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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 1/3] stress test for repack concurrently @ 2025-12-13 17:13 Mikhail Nikalayeu <[email protected]> 0 siblings, 0 replies; 267+ messages in thread From: Mikhail Nikalayeu @ 2025-12-13 17:13 UTC (permalink / raw) --- contrib/amcheck/meson.build | 1 + contrib/amcheck/t/007_repack_1.pl | 121 ++++++++++++++++++++++++++++++ doc/src/sgml/regress.sgml | 16 ++++ 3 files changed, 138 insertions(+) create mode 100644 contrib/amcheck/t/007_repack_1.pl diff --git a/contrib/amcheck/meson.build b/contrib/amcheck/meson.build index d5137ef691d..cb4bc32e98a 100644 --- a/contrib/amcheck/meson.build +++ b/contrib/amcheck/meson.build @@ -50,6 +50,7 @@ tests += { 't/004_verify_nbtree_unique.pl', 't/005_pitr.pl', 't/006_verify_gin.pl', + 't/007_repack_1.pl', ], }, } diff --git a/contrib/amcheck/t/007_repack_1.pl b/contrib/amcheck/t/007_repack_1.pl new file mode 100644 index 00000000000..17f3caa3a38 --- /dev/null +++ b/contrib/amcheck/t/007_repack_1.pl @@ -0,0 +1,121 @@ +# Copyright (c) 2021-2026, PostgreSQL Global Development Group + +# Test REPACK CONCURRENTLY with concurrent modifications +use strict; +use warnings FATAL => 'all'; + +use PostgreSQL::Test::Cluster; +use PostgreSQL::Test::Utils; + +use Test::More; + +# PG_TEST_EXTRA carries a numerical stress value; 0 disables the test, +# 1 means the test takes about 6 seconds, and the increase should be +# roughly linear. +my $matched = ($ENV{PG_TEST_EXTRA} // '') =~ /\bstress_concurrently(?:=(?<stressval>[0-9]*))?\b/; +my $stressval = $+{stressval} // 1; +if (!$matched or $stressval == 0) +{ + plan skip_all => 'skipping disabled REPACK CONCURRENTLY stress test'; +} + +note "stressval is $stressval"; + +my $node; + +# Test set-up +$node = PostgreSQL::Test::Cluster->new('CIC_test'); +$node->init; +$node->append_conf('postgresql.conf', + 'lock_timeout = ' . (1000 * $PostgreSQL::Test::Utils::timeout_default)); +$node->append_conf( + 'postgresql.conf', qq( +wal_level = logical +)); + +my $nrows = 10_000 * $stressval; +my $duration = 6 * $stressval; +my $no_hot = int(rand(2)); + +$node->start; +$node->safe_psql('postgres', q(CREATE TABLE tbl(id int PRIMARY KEY, val int))); + +if ($no_hot) +{ + $node->safe_psql('postgres', q(CREATE INDEX test_idx ON tbl(val);)); +} +else +{ + $node->safe_psql('postgres', q(CREATE INDEX test_idx ON tbl(id);)); +} + + +# Load amcheck +$node->safe_psql('postgres', q(CREATE EXTENSION amcheck)); + +# Insert $nrows rows into tbl +$node->safe_psql('postgres', qq( + INSERT INTO tbl SELECT g, g FROM generate_series(1, $nrows) g +)); + +my $sum = $node->safe_psql('postgres', q( + SELECT SUM(val) AS sum FROM tbl +)); + + +$node->pgbench( +"--no-vacuum --client=30 --jobs=4 --exit-on-abort -T $duration", +0, +[qr{actually processed}], +[qr{^$}], +'concurrent operations with REINDEX/CREATE INDEX CONCURRENTLY', +{ + 'concurrent_ops' => qq( + SELECT pg_try_advisory_lock(42)::integer AS gotlock \\gset + \\if :gotlock + REPACK (CONCURRENTLY) tbl USING INDEX tbl_pkey; + SELECT bt_index_parent_check('tbl_pkey', heapallindexed => true); + SELECT bt_index_parent_check('test_idx', heapallindexed => true); + \\sleep 10 ms + + REPACK (CONCURRENTLY) tbl USING INDEX test_idx; + SELECT bt_index_parent_check('tbl_pkey', heapallindexed => true); + SELECT bt_index_parent_check('test_idx', heapallindexed => true); + \\sleep 10 ms + + REPACK (CONCURRENTLY) tbl; + SELECT bt_index_parent_check('tbl_pkey', heapallindexed => true); + SELECT bt_index_parent_check('test_idx', heapallindexed => true); + \\sleep 10 ms + + SELECT pg_advisory_unlock(42); + \\else + \\set num_a random(1, $nrows) + \\set num_b random(1, $nrows) + \\set diff random(1, 10000) + BEGIN; + UPDATE tbl SET val = val + :diff WHERE id = :num_a; + \\sleep 1 ms + UPDATE tbl SET val = val - :diff WHERE id = :num_b; + \\sleep 1 ms + COMMIT; + + BEGIN + --TRANSACTION ISOLATION LEVEL REPEATABLE READ + ; + SELECT 1; + \\sleep 1 ms + SELECT COALESCE(SUM(val), 0) AS sum FROM tbl \\gset p_ + \\if :p_sum != $sum + COMMIT; + SELECT (:p_sum) / 0; + \\endif + + COMMIT; + \\endif + ) +}); + +$node->stop; + +done_testing(); diff --git a/doc/src/sgml/regress.sgml b/doc/src/sgml/regress.sgml index c74941bfbf2..c5b1b79a60c 100644 --- a/doc/src/sgml/regress.sgml +++ b/doc/src/sgml/regress.sgml @@ -386,6 +386,22 @@ make check-world PG_TEST_EXTRA='kerberos ldap ssl load_balance libpq_encryption' </listitem> </varlistentry> + <varlistentry> + <term><literal>stress_concurrently</literal><optional>=VALUE</optional></term> + <listitem> + <para> + Run some additional, moderately expensive tests for commands with a + <literal>CONCURRENTLY</literal> option. Optionally, an integer can be + given after an equal sign, which affects how long each such test + runs for. + Each test is calibrated so that, when given a value of 10, + it runs for approximately 60 seconds. + If no value is given, 1 is assumed. + Explicitly giving a value of 0 causes the test to be skipped. + </para> + </listitem> + </varlistentry> + <varlistentry> <term><literal>wal_consistency_checking</literal></term> <listitem> -- 2.47.3 --tbdehtstrqwksfdh Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename="0002-one-more-stress-test-for-repack-concurrently.patch" ^ permalink raw reply [nested|flat] 267+ messages in thread
end of thread, other threads:[~2025-12-13 17:13 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]> 2025-12-13 17:13 [PATCH 1/3] stress test for repack concurrently Mikhail Nikalayeu <[email protected]>
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