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[PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. 267+ messages / 2 participants [nested] [flat]
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. @ 2024-05-18 01:41 Thomas Munro <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Thomas Munro @ 2024-05-18 01:41 UTC (permalink / raw) When backend processes were launched in EXEC_BACKEND builds, they would run LocalProcessControlFile() to read in pg_control and extract several important settings. This happens too early to acquire ControlFileLock, and the postmaster is also not allowed to acquire ControlFileLock, so it can't safely take a copy to give to the child. Instead, pass down the "proto-controlfile" that was read by the postmaster in LocalProcessControlFile(). Introduce functions ExportProtoControlFile() and ImportProtoControlFile() to allow that. Subprocesses will extract information from that, and then later attach to the current control file in shared memory. Reported-by: Melanie Plageman <[email protected]> per Windows CI failure Discussion: https://postgr.es/m/CAAKRu_YNGwEYrorQYza_W8tU%2B%3DtoXRHG8HpyHC-KDbZqA_ZVSA%40mail.gmail.com --- src/backend/access/transam/xlog.c | 46 +++++++++++++++++++++++-- src/backend/postmaster/launch_backend.c | 21 +++++++---- src/include/access/xlog.h | 5 +++ 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 13ec6225b85..e52517eb9c1 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -575,6 +575,10 @@ static WALInsertLockPadded *WALInsertLocks = NULL; */ static ControlFileData *ControlFile = NULL; +#ifdef EXEC_BACKEND +static ControlFileData *ProtoControlFile = NULL; +#endif + /* * Calculate the amount of space left on the page after 'endptr'. Beware * multiple evaluation! @@ -692,6 +696,7 @@ static bool PerformRecoveryXLogAction(void); static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version); static void WriteControlFile(void); static void ReadControlFile(void); +static void ScanControlFile(void); static void UpdateControlFile(void); static char *str_time(pg_time_t tnow, char *buf, size_t bufsize); @@ -4385,9 +4390,7 @@ WriteControlFile(void) static void ReadControlFile(void) { - pg_crc32c crc; int fd; - char wal_segsz_str[20]; int r; /* @@ -4420,6 +4423,15 @@ ReadControlFile(void) close(fd); + ScanControlFile(); +} + +static void +ScanControlFile(void) +{ + static char wal_segsz_str[20]; + pg_crc32c crc; + /* * Check for expected pg_control format version. If this is wrong, the * CRC check will likely fail because we'll be checking the wrong number @@ -4941,8 +4953,33 @@ LocalProcessControlFile(bool reset) Assert(reset || ControlFile == NULL); ControlFile = palloc_object(ControlFileData); ReadControlFile(); + +#ifdef EXEC_BACKEND + /* We need to be able to give this to subprocesses. */ + ProtoControlFile = ControlFile; +#endif } +#ifdef EXEC_BACKEND +void +ExportProtoControlFile(ControlFileData *copy) +{ + *copy = *ProtoControlFile; +} + +/* + * Like LocalProcessControlFile(), but used early in EXEC_BACKEND children's + * startup. This receives the same file that the postmaster first read. + */ +void +ImportProtoControlFile(const ControlFileData *copy) +{ + ControlFile = palloc(sizeof(ControlFileData)); + *ControlFile = *copy; + ScanControlFile(); +} +#endif + /* * Get the wal_level from the control file. For a standby, this value should be * considered as its active wal_level, because it may be different from what @@ -5061,7 +5098,12 @@ XLOGShmemInit(void) if (localControlFile) { memcpy(ControlFile, localControlFile, sizeof(ControlFileData)); +#ifdef EXEC_BACKEND + /* We still hold a reference to give to subprocesses. */ + Assert(ProtoControlFile == localControlFile); +#else pfree(localControlFile); +#endif } /* diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 45690b11c99..e08a405f949 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -33,6 +33,9 @@ #include <unistd.h> +#include "access/xlog.h" +#include "catalog/pg_control.h" +#include "common/file_utils.h" #include "libpq/libpq-be.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" @@ -133,6 +136,14 @@ typedef struct int MyPMChildSlot; + /* + * A copy of the ControlFileData from early in Postmaster startup. We + * need to access its contents it at a phase of initialization before we + * are allowed to acquire LWLocks, so we can't just use shared memory or + * read the file from disk. + */ + ControlFileData proto_controlfile; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -659,12 +670,6 @@ SubPostmasterMain(int argc, char *argv[]) */ checkDataDir(); - /* - * (re-)read control file, as it contains config. The postmaster will - * already have read this, but this process doesn't know about that. - */ - LocalProcessControlFile(false); - /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we @@ -752,6 +757,8 @@ save_backend_variables(BackendParameters *param, param->MaxBackends = MaxBackends; param->num_pmchild_slots = num_pmchild_slots; + ExportProtoControlFile(¶m->proto_controlfile); + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -1026,6 +1033,8 @@ restore_backend_variables(BackendParameters *param) strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); + ImportProtoControlFile(¶m->proto_controlfile); + /* * We need to restore fd.c's counts of externally-opened FDs; to avoid * confusion, be sure to do this after restoring max_safe_fds. (Note: diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index fdfb572467b..f1f3ad4e96e 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -208,6 +208,7 @@ typedef enum WALAvailability struct XLogRecData; struct XLogReaderState; +struct ControlFileData; extern XLogRecPtr XLogInsertRecord(struct XLogRecData *rdata, XLogRecPtr fpw_lsn, @@ -250,6 +251,10 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(uint32 data_checksum_version); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +#ifdef EXEC_BACKEND +extern void ExportProtoControlFile(struct ControlFileData *copy); +extern void ImportProtoControlFile(const struct ControlFileData *copy); +#endif extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); -- 2.47.3 --dhbc6bswyy6qufwn-- ^ permalink raw reply [nested|flat] 267+ messages in thread
* [PATCH v9 2/2] handle relation statistics correctly during rewrites @ 2025-11-04 13:52 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Bertrand Drouvot @ 2025-11-04 13:52 UTC (permalink / raw) Now that PGSTAT_KIND_RELATION is keyed by refilenode, we need to handle rewrites. To do so, this patch: - Adds PgStat_PendingRewrite, a new struct to track rewrite operations within a transaction, storing the old locator, new locator, and original locator (for rewrite chains). This allows stats to be copied from the original location to the final location at commit time. - Adds a new function, pgstat_mark_rewrite(), called when a table rewrite begins. It records the rewrite operation in a local list and detects rewrite chains by checking if the old_locator matches any existing new_locator, preserving the chain's original_locator. - Modifies pgstat_copy_relation_stats(), to accept RelFileLocators instead of Relations, with a new increment parameter to accumulate stats (needed for rewrite chains with DML between rewrites). - Ensures that AtEOXact_PgStat_Relations(), AtPrepare_PgStat_Relations(), pgstat_twophase_postcommit()/postabort() pgstat_drop_relation() handle the PgStat_PendingRewrite list correctly. Note that due to the new flush call in pgstat_twophase_postcommit() we can not call GetCurrentTransactionStopTimestamp() in pgstat_relation_flush_cb(). So, adding a check to handle this special case and call GetCurrentTimestamp() instead. Note that we'd call GetCurrentTimestamp() only if there is a rewrite, so that the GetCurrentTimestamp() extra cost should be negligible. Another solution could be to trigger the flush from FinishPreparedTransaction() but that's not worth the extra complexity. The new pending_rewrites list is traversed in multiple places. The overhead should be negligible in comparison to a rewrite and the list should not contain a lot of rewrites in practice. The pending_rewrites list is traversed in multiple places. In typical usage, the list will contain only a few entries so the traversal cost is negligible ( furthermore in comparison to a rewrite). --- src/backend/catalog/index.c | 2 +- src/backend/commands/cluster.c | 5 + src/backend/commands/tablecmds.c | 6 + src/backend/utils/activity/pgstat_relation.c | 391 ++++++++++++++++++- src/backend/utils/activity/pgstat_xact.c | 25 +- src/backend/utils/cache/relcache.c | 6 + src/include/pgstat.h | 5 +- src/tools/pgindent/typedefs.list | 1 + 8 files changed, 424 insertions(+), 17 deletions(-) 92.8% src/backend/utils/activity/ 4.9% src/backend/ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 8dea58ad96b..b71925a22c3 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -1795,7 +1795,7 @@ index_concurrently_swap(Oid newIndexId, Oid oldIndexId, const char *oldName) changeDependenciesOn(RelationRelationId, oldIndexId, newIndexId); /* copy over statistics from old to new index */ - pgstat_copy_relation_stats(newClassRel, oldClassRel); + pgstat_copy_relation_stats(newClassRel->rd_locator, oldClassRel->rd_locator, false); /* Copy data of pg_statistic from the old index to the new one */ CopyStatistics(oldIndexId, newIndexId); diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c index 2120c85ccb4..6155b12afab 100644 --- a/src/backend/commands/cluster.c +++ b/src/backend/commands/cluster.c @@ -1196,6 +1196,11 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class, rel1 = relation_open(r1, NoLock); rel2 = relation_open(r2, NoLock); + + /* Mark that a rewrite happened */ + if (RELKIND_HAS_STORAGE(rel1->rd_rel->relkind)) + pgstat_mark_rewrite(rel1->rd_locator, rel2->rd_locator); + rel2->rd_createSubid = rel1->rd_createSubid; rel2->rd_newRelfilelocatorSubid = rel1->rd_newRelfilelocatorSubid; rel2->rd_firstRelfilelocatorSubid = rel1->rd_firstRelfilelocatorSubid; diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 6b1a00ed477..9de70f321ed 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -16884,6 +16884,7 @@ ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode) Oid reltoastrelid; RelFileNumber newrelfilenumber; RelFileLocator newrlocator; + RelFileLocator oldrlocator; List *reltoastidxids = NIL; ListCell *lc; @@ -16922,6 +16923,7 @@ ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode) newrlocator = rel->rd_locator; newrlocator.relNumber = newrelfilenumber; newrlocator.spcOid = newTableSpace; + oldrlocator = rel->rd_locator; /* hand off to AM to actually create new rel storage and copy the data */ if (rel->rd_rel->relkind == RELKIND_INDEX) @@ -16934,6 +16936,10 @@ ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode) table_relation_copy_data(rel, &newrlocator); } + /* mark that a rewrite happened */ + if (RELKIND_HAS_STORAGE(rel->rd_rel->relkind)) + pgstat_mark_rewrite(oldrlocator, newrlocator); + /* * Update the pg_class row. * diff --git a/src/backend/utils/activity/pgstat_relation.c b/src/backend/utils/activity/pgstat_relation.c index 48bf93cae6e..b6ba8fdf440 100644 --- a/src/backend/utils/activity/pgstat_relation.c +++ b/src/backend/utils/activity/pgstat_relation.c @@ -30,6 +30,19 @@ #include "utils/syscache.h" #include "utils/timestamp.h" +/* Pending rewrite operations for stats copying */ +typedef struct PgStat_PendingRewrite +{ + RelFileLocator old_locator; + RelFileLocator new_locator; + RelFileLocator original_locator; + int nest_level; /* Transaction nesting level where rewrite + * occurred */ + struct PgStat_PendingRewrite *next; +} PgStat_PendingRewrite; + +/* The pending rewrites list for current transaction */ +static PgStat_PendingRewrite *pending_rewrites = NULL; /* Record that's written to 2PC state file when pgstat state is persisted */ typedef struct TwoPhasePgStatRecord @@ -43,6 +56,8 @@ typedef struct TwoPhasePgStatRecord PgStat_Counter deleted_pre_truncdrop; RelFileLocator locator; /* table's rd_locator */ bool truncdropped; /* was the relation truncated/dropped? */ + RelFileLocator rewrite_old_locator; + int rewrite_nest_level; } TwoPhasePgStatRecord; @@ -54,27 +69,70 @@ static void restore_truncdrop_counters(PgStat_TableXactStatus *trans); /* - * Copy stats between relations. This is used for things like REINDEX + * Copy stats between RelFileLocator. This is used for things like REINDEX * CONCURRENTLY. */ void -pgstat_copy_relation_stats(Relation dst, Relation src) +pgstat_copy_relation_stats(RelFileLocator dst, RelFileLocator src, bool increment) { PgStat_StatTabEntry *srcstats; PgStatShared_Relation *dstshstats; PgStat_EntryRef *dst_ref; - srcstats = pgstat_fetch_stat_tabentry_ext(RelationGetRelid(src)); + srcstats = (PgStat_StatTabEntry *) pgstat_fetch_entry(PGSTAT_KIND_RELATION, + src.dbOid, + RelFileLocatorToPgStatObjid(src)); if (!srcstats) return; dst_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_RELATION, - dst->rd_rel->relisshared ? InvalidOid : MyDatabaseId, - RelationGetRelid(dst), + dst.dbOid, + RelFileLocatorToPgStatObjid(dst), false); dstshstats = (PgStatShared_Relation *) dst_ref->shared_stats; - dstshstats->stats = *srcstats; + + if (!increment) + dstshstats->stats = *srcstats; + else + { + /* Increment those statistics */ +#define RELFSTAT_ACC(fld, stats_to_add) \ + (dstshstats->stats.fld += stats_to_add->fld) + RELFSTAT_ACC(numscans, srcstats); + RELFSTAT_ACC(tuples_returned, srcstats); + RELFSTAT_ACC(tuples_fetched, srcstats); + RELFSTAT_ACC(tuples_inserted, srcstats); + RELFSTAT_ACC(tuples_updated, srcstats); + RELFSTAT_ACC(tuples_deleted, srcstats); + RELFSTAT_ACC(tuples_hot_updated, srcstats); + RELFSTAT_ACC(tuples_newpage_updated, srcstats); + RELFSTAT_ACC(live_tuples, srcstats); + RELFSTAT_ACC(dead_tuples, srcstats); + RELFSTAT_ACC(mod_since_analyze, srcstats); + RELFSTAT_ACC(ins_since_vacuum, srcstats); + RELFSTAT_ACC(blocks_fetched, srcstats); + RELFSTAT_ACC(blocks_hit, srcstats); + RELFSTAT_ACC(vacuum_count, srcstats); + RELFSTAT_ACC(autovacuum_count, srcstats); + RELFSTAT_ACC(analyze_count, srcstats); + RELFSTAT_ACC(autoanalyze_count, srcstats); + RELFSTAT_ACC(total_vacuum_time, srcstats); + RELFSTAT_ACC(total_autovacuum_time, srcstats); + RELFSTAT_ACC(total_analyze_time, srcstats); + RELFSTAT_ACC(total_autoanalyze_time, srcstats); +#undef RELFSTAT_ACC + + /* Replace those statistics */ +#define RELFSTAT_REP(fld, stats_to_rep) \ + (dstshstats->stats.fld = stats_to_rep->fld) + RELFSTAT_REP(lastscan, srcstats); + RELFSTAT_REP(last_vacuum_time, srcstats); + RELFSTAT_REP(last_autovacuum_time, srcstats); + RELFSTAT_REP(last_analyze_time, srcstats); + RELFSTAT_REP(last_autoanalyze_time, srcstats); +#undef RELFSTAT_REP + } pgstat_unlock_entry(dst_ref); } @@ -136,6 +194,7 @@ void pgstat_assoc_relation(Relation rel) { RelFileLocator locator; + PgStat_TableStatus *pgstat_info; Assert(rel->pgstat_enabled); Assert(rel->pgstat_info == NULL); @@ -164,14 +223,54 @@ pgstat_assoc_relation(Relation rel) locator.relNumber = rel->rd_id; } + /* + * If this relation was rewritten during the current transaction we may be + * reopening it with its new RelFileLocator. In that case, continue using + * the stats entry associated with the old locator rather than creating a + * new one. This ensures all stats from before and after the rewrite are + * tracked in a single entry which will be properly copied to the new + * locator at transaction commit. + */ + if (pending_rewrites != NULL) + { + PgStat_PendingRewrite *rewrite; + + for (rewrite = pending_rewrites; rewrite != NULL; rewrite = rewrite->next) + { + if (locator.dbOid == rewrite->new_locator.dbOid && + locator.spcOid == rewrite->new_locator.spcOid && + locator.relNumber == rewrite->new_locator.relNumber) + { + pgstat_info = pgstat_prep_relation_pending(rewrite->old_locator); + goto found_entry; + } + } + } + /* Else find or make the PgStat_TableStatus entry, and update link */ - rel->pgstat_info = pgstat_prep_relation_pending(locator); + pgstat_info = pgstat_prep_relation_pending(locator); + +found_entry: + rel->pgstat_info = pgstat_info; + + /* + * For relations stats, we key by physical file location, not by relation + * OID. This means during operations like ALTER TYPE it's possible that + * the relation OID changes but the relfilenode stays the same (no actual + * rewrite needed). Unlink the old relation first. + */ + if (pgstat_info->relation != NULL && + pgstat_info->relation != rel) + { + pgstat_info->relation->pgstat_info = NULL; + pgstat_info->relation = NULL; + } /* don't allow link a stats to multiple relcache entries */ - Assert(rel->pgstat_info->relation == NULL); + Assert(pgstat_info->relation == NULL); /* mark this relation as the owner */ - rel->pgstat_info->relation = rel; + pgstat_info->relation = rel; } /* @@ -214,14 +313,37 @@ pgstat_drop_relation(Relation rel) { int nest_level = GetCurrentTransactionNestLevel(); PgStat_TableStatus *pgstat_info; + bool skip_transactional_drop = false; /* don't track stats for relations without storage */ if (!RELKIND_HAS_STORAGE(rel->rd_rel->relkind)) return; - pgstat_drop_transactional(PGSTAT_KIND_RELATION, - rel->rd_locator.dbOid, - RelFileLocatorToPgStatObjid(rel->rd_locator)); + /* Check if this drop is part of a pending rewrite */ + if (pending_rewrites != NULL) + { + PgStat_PendingRewrite *rewrite; + + for (rewrite = pending_rewrites; rewrite != NULL; rewrite = rewrite->next) + { + if (rel->rd_locator.dbOid == rewrite->old_locator.dbOid && + rel->rd_locator.spcOid == rewrite->old_locator.spcOid && + rel->rd_locator.relNumber == rewrite->old_locator.relNumber) + { + skip_transactional_drop = true; + break; + } + } + } + + /* + * If it is part of a rewrite, drop its stats later, for example in + * AtEOXact_PgStat_Relations(), so skip it here. + */ + if (!skip_transactional_drop) + pgstat_drop_transactional(PGSTAT_KIND_RELATION, + rel->rd_locator.dbOid, + RelFileLocatorToPgStatObjid(rel->rd_locator)); if (!pgstat_should_count_relation(rel)) return; @@ -666,6 +788,48 @@ AtEOXact_PgStat_Relations(PgStat_SubXactStatus *xact_state, bool isCommit) } tabstat->trans = NULL; } + + /* preserve the stats in case of rewrite */ + if (isCommit && pending_rewrites != NULL) + { + PgStat_PendingRewrite *rewrite; + PgStat_PendingRewrite *prev = NULL; + PgStat_PendingRewrite *current = pending_rewrites; + PgStat_PendingRewrite *next; + + /* reverse the rewrites list to process in chronological order */ + while (current != NULL) + { + next = current->next; + current->next = prev; + prev = current; + current = next; + } + + /* now process rewrites in chronological order */ + for (rewrite = prev; rewrite != NULL; rewrite = rewrite->next) + { + PgStat_EntryRef *old_entry_ref; + + old_entry_ref = pgstat_fetch_pending_entry(PGSTAT_KIND_RELATION, + rewrite->old_locator.dbOid, + RelFileLocatorToPgStatObjid(rewrite->old_locator)); + + if (old_entry_ref && old_entry_ref->pending) + pgstat_relation_flush_cb(old_entry_ref, false); + + pgstat_copy_relation_stats(rewrite->new_locator, + rewrite->old_locator, true); + + /* drop old locator's stats */ + if (!pgstat_drop_entry(PGSTAT_KIND_RELATION, + rewrite->old_locator.dbOid, + RelFileLocatorToPgStatObjid(rewrite->old_locator))) + pgstat_request_entry_refs_gc(); + } + } + + pending_rewrites = NULL; } /* @@ -681,6 +845,30 @@ AtEOSubXact_PgStat_Relations(PgStat_SubXactStatus *xact_state, bool isCommit, in PgStat_TableXactStatus *trans; PgStat_TableXactStatus *next_trans; + /* + * If we don't commit then remove the associated rewrites if any, to keep + * the rewrite chain in sync with what will be eventually committed. + */ + if (!isCommit) + { + PgStat_PendingRewrite **rewrite_ptr = &pending_rewrites; + + while (*rewrite_ptr != NULL) + { + if ((*rewrite_ptr)->nest_level >= nestDepth) + { + PgStat_PendingRewrite *to_remove = *rewrite_ptr; + + *rewrite_ptr = (*rewrite_ptr)->next; + pfree(to_remove); + } + else + { + rewrite_ptr = &((*rewrite_ptr)->next); + } + } + } + for (trans = xact_state->first; trans != NULL; trans = next_trans) { PgStat_TableStatus *tabstat; @@ -760,11 +948,19 @@ void AtPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state) { PgStat_TableXactStatus *trans; + PgStat_PendingRewrite *rewrite; + /* + * For each tabstat, find its matching rewrite and remove it from the + * pending rewrites list. This way, after processing all tabstats, pending + * rewrites will only contain rewrite only transactions. + */ for (trans = xact_state->first; trans != NULL; trans = trans->next) { PgStat_TableStatus *tabstat PG_USED_FOR_ASSERTS_ONLY; TwoPhasePgStatRecord record; + PgStat_PendingRewrite **rewrite_ptr; + bool found_rewrite = false; Assert(trans->nest_level == 1); Assert(trans->upper == NULL); @@ -784,10 +980,83 @@ AtPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state) record.locator = tabstat->locator; record.truncdropped = trans->truncdropped; + record.rewrite_nest_level = 0; + + /* + * Look for a matching rewrite and remove it from pending rewrites. We + * check three possible matches: + * + * The new_locator when stats have been added after the rewrite. The + * old_locator when stats have been added before the rewrite but not + * after. The original_locator when this tabstat is part of a rewrite + * chain. + */ + rewrite_ptr = &pending_rewrites; + while (*rewrite_ptr != NULL) + { + rewrite = *rewrite_ptr; + + if ((record.locator.dbOid == rewrite->new_locator.dbOid && + record.locator.spcOid == rewrite->new_locator.spcOid && + record.locator.relNumber == rewrite->new_locator.relNumber) || + (tabstat->locator.dbOid == rewrite->old_locator.dbOid && + tabstat->locator.spcOid == rewrite->old_locator.spcOid && + tabstat->locator.relNumber == rewrite->old_locator.relNumber) || + (tabstat->locator.dbOid == rewrite->original_locator.dbOid && + tabstat->locator.spcOid == rewrite->original_locator.spcOid && + tabstat->locator.relNumber == rewrite->original_locator.relNumber)) + { + /* + * Found matching rewrite. Record the rewrite information and + * remove this rewrite from the list since it's now handled. + */ + record.rewrite_old_locator = rewrite->original_locator; + record.rewrite_nest_level = rewrite->nest_level; + record.locator = rewrite->new_locator; + found_rewrite = true; + + /* Remove from pending_rewrites list */ + *rewrite_ptr = rewrite->next; + pfree(rewrite); + break; + } + else + { + /* Move to next rewrite in the list */ + rewrite_ptr = &(rewrite->next); + } + } + + /* If no rewrite found, clear the rewrite fields */ + if (!found_rewrite) + { + memset(&record.rewrite_old_locator, 0, sizeof(RelFileLocator)); + } + + RegisterTwoPhaseRecord(TWOPHASE_RM_PGSTAT_ID, 0, + &record, sizeof(TwoPhasePgStatRecord)); + } + + /* + * Now process any rewrites still pending. These are rewrite only + * transactions. We need to preserve their stats even though there's no + * tabstat entry for them. + */ + for (rewrite = pending_rewrites; rewrite != NULL; rewrite = rewrite->next) + { + TwoPhasePgStatRecord record; + + memset(&record, 0, sizeof(TwoPhasePgStatRecord)); + record.locator = rewrite->new_locator; + record.rewrite_old_locator = rewrite->original_locator; + record.rewrite_nest_level = rewrite->nest_level; + record.truncdropped = false; RegisterTwoPhaseRecord(TWOPHASE_RM_PGSTAT_ID, 0, &record, sizeof(TwoPhasePgStatRecord)); } + + pending_rewrites = NULL; } /* @@ -810,6 +1079,8 @@ PostPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state) tabstat = trans->parent; tabstat->trans = NULL; } + + pending_rewrites = NULL; } /* @@ -845,6 +1116,29 @@ pgstat_twophase_postcommit(FullTransactionId fxid, uint16 info, pgstat_info->counts.changed_tuples += rec->tuples_inserted + rec->tuples_updated + rec->tuples_deleted; + + if (rec->rewrite_nest_level > 0) + { + PgStat_EntryRef *old_entry_ref; + + /* Flush any pending stats for old locator first */ + old_entry_ref = pgstat_fetch_pending_entry(PGSTAT_KIND_RELATION, + rec->rewrite_old_locator.dbOid, + RelFileLocatorToPgStatObjid(rec->rewrite_old_locator)); + + if (old_entry_ref && old_entry_ref->pending) + pgstat_relation_flush_cb(old_entry_ref, false); + + /* Copy stats from old to new locator */ + pgstat_copy_relation_stats(rec->locator, rec->rewrite_old_locator, + true); + + /* Drop old locator's stats */ + if (!pgstat_drop_entry(PGSTAT_KIND_RELATION, + rec->rewrite_old_locator.dbOid, + RelFileLocatorToPgStatObjid(rec->rewrite_old_locator))) + pgstat_request_entry_refs_gc(); + } } /* @@ -859,9 +1153,26 @@ pgstat_twophase_postabort(FullTransactionId fxid, uint16 info, { TwoPhasePgStatRecord *rec = (TwoPhasePgStatRecord *) recdata; PgStat_TableStatus *pgstat_info; + RelFileLocator target_locator; + + /* + * For aborted transactions with rewrites (like TRUNCATE), we need to + * restore stats to the old locator, not the new one. The new locator + * should be dropped since the rewrite is being rolled back. + */ + if (rec->rewrite_nest_level > 0) + { + /* Use the old locator */ + target_locator = rec->rewrite_old_locator; + } + else + { + /* No rewrite, use the original locator */ + target_locator = rec->locator; + } /* Find or create a tabstat entry for the target locator */ - pgstat_info = pgstat_prep_relation_pending(rec->locator); + pgstat_info = pgstat_prep_relation_pending(target_locator); /* Same math as in AtEOXact_PgStat, abort case */ if (rec->truncdropped) @@ -916,7 +1227,17 @@ pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait) tabentry->numscans += lstats->counts.numscans; if (lstats->counts.numscans) { - TimestampTz t = GetCurrentTransactionStopTimestamp(); + TimestampTz t; + + /* + * Checking the transaction state due to the flush call in + * pgstat_twophase_postcommit() that would break the assertion on the + * state in GetCurrentTransactionStopTimestamp(). + */ + if (!IsTransactionState()) + t = GetCurrentTransactionStopTimestamp(); + else + t = GetCurrentTimestamp(); if (t > tabentry->lastscan) tabentry->lastscan = t; @@ -1167,3 +1488,45 @@ pgstat_reloid_to_relfilelocator(Oid reloid, RelFileLocator *locator) ReleaseSysCache(tuple); return result; } + +/* + * Mark that a relation rewrite has occurred, preserving the original locator + * so stats can be copied at transaction commit. + */ +void +pgstat_mark_rewrite(RelFileLocator old_locator, RelFileLocator new_locator) +{ + PgStat_PendingRewrite *rewrite; + PgStat_PendingRewrite *existing; + RelFileLocator original_locator = old_locator; + + for (existing = pending_rewrites; existing != NULL; existing = existing->next) + { + if (old_locator.dbOid == existing->new_locator.dbOid && + old_locator.spcOid == existing->new_locator.spcOid && + old_locator.relNumber == existing->new_locator.relNumber) + { + original_locator = existing->original_locator; + break; + } + } + + /* Allocate in TopTransactionContext memory context */ + rewrite = MemoryContextAlloc(TopTransactionContext, + sizeof(PgStat_PendingRewrite)); + + rewrite->old_locator = old_locator; + rewrite->new_locator = new_locator; + rewrite->original_locator = original_locator; + rewrite->nest_level = GetCurrentTransactionNestLevel(); + + /* Add to the list */ + rewrite->next = pending_rewrites; + pending_rewrites = rewrite; +} + +void +pgstat_clear_rewrite(void) +{ + pending_rewrites = NULL; +} diff --git a/src/backend/utils/activity/pgstat_xact.c b/src/backend/utils/activity/pgstat_xact.c index bc9864bd8d9..f8cf3755ce2 100644 --- a/src/backend/utils/activity/pgstat_xact.c +++ b/src/backend/utils/activity/pgstat_xact.c @@ -55,6 +55,8 @@ AtEOXact_PgStat(bool isCommit, bool parallel) } pgStatXactStack = NULL; + pgstat_clear_rewrite(); + /* Make sure any stats snapshot is thrown away */ pgstat_clear_snapshot(); } @@ -360,8 +362,29 @@ create_drop_transactional_internal(PgStat_Kind kind, Oid dboid, uint64 objid, bo void pgstat_create_transactional(PgStat_Kind kind, Oid dboid, uint64 objid) { - if (pgstat_get_entry_ref(kind, dboid, objid, false, NULL)) + PgStat_EntryRef *entry_ref; + + entry_ref = pgstat_get_entry_ref(kind, dboid, objid, false, NULL); + + if (entry_ref) { + /* + * For relations stats, we key by physical file location, not by + * relation OID. This means during operations like ALTER TYPE where + * the relation OID changes but the relfilenode stays the same (no + * actual rewrite needed), we'll find an existing entry. + * + * This is expected behavior, we want to preserve stats across the + * catalog change. Simply reset and recreate the entry for the new + * relation OID without warning. + */ + if (kind == PGSTAT_KIND_RELATION) + { + pgstat_reset(kind, dboid, objid); + create_drop_transactional_internal(kind, dboid, objid, true); + return; + } + ereport(WARNING, errmsg("resetting existing statistics for kind %s, db=%u, oid=%" PRIu64, (pgstat_get_kind_info(kind))->name, dboid, diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c index 2d0cb7bcfd4..c98e5c51d63 100644 --- a/src/backend/utils/cache/relcache.c +++ b/src/backend/utils/cache/relcache.c @@ -85,6 +85,7 @@ #include "utils/inval.h" #include "utils/lsyscache.h" #include "utils/memutils.h" +#include "utils/pgstat_internal.h" #include "utils/relmapper.h" #include "utils/resowner.h" #include "utils/snapmgr.h" @@ -3780,6 +3781,7 @@ RelationSetNewRelfilenumber(Relation relation, char persistence) MultiXactId minmulti = InvalidMultiXactId; TransactionId freezeXid = InvalidTransactionId; RelFileLocator newrlocator; + RelFileLocator oldrlocator = relation->rd_locator; if (!IsBinaryUpgrade) { @@ -3951,6 +3953,10 @@ RelationSetNewRelfilenumber(Relation relation, char persistence) table_close(pg_class, RowExclusiveLock); + /* Mark that a rewrite happened */ + if (RELKIND_HAS_STORAGE(relation->rd_rel->relkind)) + pgstat_mark_rewrite(oldrlocator, newrlocator); + /* * Make the pg_class row change or relation map change visible. This will * cause the relcache entry to get updated, too. diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 3102f86aa24..8750c025bbe 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -670,7 +670,7 @@ extern PgStat_FunctionCounts *find_funcstat_entry(Oid func_id); extern void pgstat_create_relation(Relation rel); extern void pgstat_drop_relation(Relation rel); -extern void pgstat_copy_relation_stats(Relation dst, Relation src); +extern void pgstat_copy_relation_stats(RelFileLocator dst, RelFileLocator src, bool increment); extern void pgstat_init_relation(Relation rel); extern void pgstat_assoc_relation(Relation rel); @@ -682,6 +682,9 @@ extern void pgstat_report_vacuum(Relation rel, PgStat_Counter livetuples, extern void pgstat_report_analyze(Relation rel, PgStat_Counter livetuples, PgStat_Counter deadtuples, bool resetcounter, TimestampTz starttime); +extern void pgstat_mark_rewrite(RelFileLocator old_locator, + RelFileLocator new_locator); +extern void pgstat_clear_rewrite(void); /* * If stats are enabled, but pending data hasn't been prepared yet, call diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list index 3451538565e..0ca3eae8026 100644 --- a/src/tools/pgindent/typedefs.list +++ b/src/tools/pgindent/typedefs.list @@ -2268,6 +2268,7 @@ PgStat_KindInfo PgStat_LocalState PgStat_PendingDroppedStatsItem PgStat_PendingIO +PgStat_PendingRewrite PgStat_SLRUStats PgStat_ShmemControl PgStat_Snapshot -- 2.34.1 --tV2Nti+lXhoeT6I5-- ^ permalink raw reply [nested|flat] 267+ messages in thread
end of thread, other threads:[~2025-11-04 13:52 UTC | newest] Thread overview: 267+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2024-05-18 01:41 [PATCH v2] Fix pg_control corruption in EXEC_BACKEND startup. Thomas Munro <[email protected]> 2025-11-04 13:52 [PATCH v9 2/2] handle relation statistics correctly during rewrites Bertrand Drouvot <[email protected]>
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