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help / color / mirror / Atom feedFrom: Amul Sul <[email protected]>
To: Chao Li <[email protected]>
Cc: Jakub Wartak <[email protected]>
Cc: Robert Haas <[email protected]>
Cc: PostgreSQL Hackers <[email protected]>
Subject: Re: pg_waldump: support decoding of WAL inside tarfile
Date: Fri, 2 Jan 2026 17:59:54 +0530
Message-ID: <CAAJ_b97nn9denP2SAjuXyjwbd3is-VnZVSkiRMJ-5YNiKfO9MA@mail.gmail.com> (raw)
In-Reply-To: <CAAJ_b94SEcBVJcsp0Y1-YvLqZWBHPQH4FhRzSJfaH_ah_eL_FQ@mail.gmail.com>
References: <CAAJ_b94bqdWN3h2J-PzzzQ2Npbwct5ZQHggn_QoYGhC2rn-=WQ@mail.gmail.com>
<CAAJ_b97PQjE4kFD8Qk6UvtLrfPMixw1nxBz0OP5Z2WB2B-uMxQ@mail.gmail.com>
<CAAJ_b97JA8ehy_UDddrnGwDt9HG5NmJq8ATtmeMqo7YD-=tLyQ@mail.gmail.com>
<CA+TgmoZjhWDG_AR1i+L1yss-wbuWvxrdRwSdVUUUnVPrJV2CnQ@mail.gmail.com>
<CAAJ_b94Uh+b41LQG45bZFK+i62EVvv972LiGWWWuR64=-64rTQ@mail.gmail.com>
<CA+TgmobF5c7ZcZHdEhqwNxGDZzWG2bDtpRaDtoVELWX_VHs_1A@mail.gmail.com>
<CAAJ_b94gK1np8d1h-2c1YoCccGXr4zspTa-FC7X_bfXZNz=-DA@mail.gmail.com>
<CA+TgmoayDY5b+bP1vRRN7A3xOP-=+tK13B2C1g-Xm1j4WTrT9Q@mail.gmail.com>
<CAAJ_b97JAF+Zuoh2FBO79hVwLeaBPwsbXw-fY+313a7LfRQ-Bg@mail.gmail.com>
<CA+Tgmoardk4VuthHc23vov+AVkhq7eT0mFUs-2ctAnP1uiTaog@mail.gmail.com>
<CAAJ_b959x5VjmLJFmN78r_QohQuuj=fde11VbbAOHn5TzgEzng@mail.gmail.com>
<CAAJ_b97_N+0sipFyq80n0jX-nKcjcQEMOSTVg8DsqkHR8dW_Sw@mail.gmail.com>
<CAKZiRmyDk5KqovS9Ez3iFHd+p-TChSt2QTtWkwJ5Ya-+4gg21g@mail.gmail.com>
<CAAJ_b956a+e8-HNEpeJ60ByFv7XJRqECPu3B0dozv0ChMRTPbQ@mail.gmail.com>
<CAAJ_b94f6sUDWiZY90O-t7SWWeSK0nMWT7AsydKkpAL90m0oMQ@mail.gmail.com>
<[email protected]>
<CAAJ_b94SEcBVJcsp0Y1-YvLqZWBHPQH4FhRzSJfaH_ah_eL_FQ@mail.gmail.com>
Attached is the rebased version, includes some code comment improvements.
Regards,
Amul
Attachments:
[application/octet-stream] v10-0001-Refactor-pg_waldump-Move-some-declarations-to-ne.patch (2.4K, 2-v10-0001-Refactor-pg_waldump-Move-some-declarations-to-ne.patch)
download | inline diff:
From 6e0f330b88eb027c36b1272b0bb7eccb1c50e39a Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Tue, 24 Jun 2025 11:33:20 +0530
Subject: [PATCH v10 1/8] Refactor: pg_waldump: Move some declarations to new
pg_waldump.h
This change prepares for a second source file in this directory to
support reading WAL from tar files. Common structures, declarations,
and functions are being exported through this include file so
they can be used in both files.
---
src/bin/pg_waldump/pg_waldump.c | 12 +++---------
src/bin/pg_waldump/pg_waldump.h | 27 +++++++++++++++++++++++++++
2 files changed, 30 insertions(+), 9 deletions(-)
create mode 100644 src/bin/pg_waldump/pg_waldump.h
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index aae655966ef..0a0e9b7caaf 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -29,6 +29,7 @@
#include "common/logging.h"
#include "common/relpath.h"
#include "getopt_long.h"
+#include "pg_waldump.h"
#include "rmgrdesc.h"
#include "storage/bufpage.h"
@@ -37,21 +38,14 @@
* give a thought about doing the same in pg_walinspect contrib module as well.
*/
+int WalSegSz;
+
static const char *progname;
-static int WalSegSz;
static volatile sig_atomic_t time_to_stop = false;
static const RelFileLocator emptyRelFileLocator = {0, 0, 0};
-typedef struct XLogDumpPrivate
-{
- TimeLineID timeline;
- XLogRecPtr startptr;
- XLogRecPtr endptr;
- bool endptr_reached;
-} XLogDumpPrivate;
-
typedef struct XLogDumpConfig
{
/* display options */
diff --git a/src/bin/pg_waldump/pg_waldump.h b/src/bin/pg_waldump/pg_waldump.h
new file mode 100644
index 00000000000..926d529f9d6
--- /dev/null
+++ b/src/bin/pg_waldump/pg_waldump.h
@@ -0,0 +1,27 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_waldump.h - decode and display WAL
+ *
+ * Copyright (c) 2025, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/bin/pg_waldump/pg_waldump.h
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_WALDUMP_H
+#define PG_WALDUMP_H
+
+#include "access/xlogdefs.h"
+
+extern int WalSegSz;
+
+/* Contains the necessary information to drive WAL decoding */
+typedef struct XLogDumpPrivate
+{
+ TimeLineID timeline;
+ XLogRecPtr startptr;
+ XLogRecPtr endptr;
+ bool endptr_reached;
+} XLogDumpPrivate;
+
+#endif /* end of PG_WALDUMP_H */
--
2.47.1
[application/octet-stream] v10-0002-Refactor-pg_waldump-Separate-logic-used-to-calcu.patch (2.5K, 3-v10-0002-Refactor-pg_waldump-Separate-logic-used-to-calcu.patch)
download | inline diff:
From cd4adf2105028a44527fe3fbbea65153de8d8a4c Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Thu, 26 Jun 2025 11:42:53 +0530
Subject: [PATCH v10 2/8] Refactor: pg_waldump: Separate logic used to
calculate the required read size.
This refactoring prepares the codebase for an upcoming patch that will
support reading WAL from tar files. The logic for calculating the
required read size has been updated to handle both normal WAL files
and WAL files located inside a tar archive.
---
src/bin/pg_waldump/pg_waldump.c | 46 +++++++++++++++++++++++----------
1 file changed, 33 insertions(+), 13 deletions(-)
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 0a0e9b7caaf..a33fc28b9d5 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -327,6 +327,35 @@ identify_target_directory(char *directory, char *fname)
return NULL; /* not reached */
}
+/*
+ * Returns the size in bytes of the data to be read. Returns -1 if the end
+ * point has already been reached.
+ */
+static inline int
+required_read_len(XLogDumpPrivate *private, XLogRecPtr targetPagePtr,
+ int reqLen)
+{
+ int count = XLOG_BLCKSZ;
+
+ if (unlikely(private->endptr_reached))
+ return -1;
+
+ if (XLogRecPtrIsValid(private->endptr))
+ {
+ if (targetPagePtr + XLOG_BLCKSZ <= private->endptr)
+ count = XLOG_BLCKSZ;
+ else if (targetPagePtr + reqLen <= private->endptr)
+ count = private->endptr - targetPagePtr;
+ else
+ {
+ private->endptr_reached = true;
+ return -1;
+ }
+ }
+
+ return count;
+}
+
/* pg_waldump's XLogReaderRoutine->segment_open callback */
static void
WALDumpOpenSegment(XLogReaderState *state, XLogSegNo nextSegNo,
@@ -384,21 +413,12 @@ WALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
XLogRecPtr targetPtr, char *readBuff)
{
XLogDumpPrivate *private = state->private_data;
- int count = XLOG_BLCKSZ;
+ int count = required_read_len(private, targetPagePtr, reqLen);
WALReadError errinfo;
- if (XLogRecPtrIsValid(private->endptr))
- {
- if (targetPagePtr + XLOG_BLCKSZ <= private->endptr)
- count = XLOG_BLCKSZ;
- else if (targetPagePtr + reqLen <= private->endptr)
- count = private->endptr - targetPagePtr;
- else
- {
- private->endptr_reached = true;
- return -1;
- }
- }
+ /* Bail out if the count to be read is not valid */
+ if (count < 0)
+ return -1;
if (!WALRead(state, readBuff, targetPagePtr, count, private->timeline,
&errinfo))
--
2.47.1
[application/octet-stream] v10-0003-Refactor-pg_waldump-Restructure-TAP-tests.patch (5.6K, 4-v10-0003-Refactor-pg_waldump-Restructure-TAP-tests.patch)
download | inline diff:
From f911d0ff34bc2c2e12fb0849785d2b5864c73594 Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Tue, 25 Nov 2025 16:12:11 +0530
Subject: [PATCH v10 3/8] Refactor: pg_waldump: Restructure TAP tests.
Restructured some tests to run inside a loop, facilitating their
re-execution for decoding WAL from tar archives.
== NOTE ==
This is not intended to be committed separately. It can be merged
with the next patch, which is the main patch implementing this
feature.
---
src/bin/pg_waldump/t/001_basic.pl | 123 ++++++++++++++++--------------
1 file changed, 67 insertions(+), 56 deletions(-)
diff --git a/src/bin/pg_waldump/t/001_basic.pl b/src/bin/pg_waldump/t/001_basic.pl
index 5db5d20136f..3288fadcf48 100644
--- a/src/bin/pg_waldump/t/001_basic.pl
+++ b/src/bin/pg_waldump/t/001_basic.pl
@@ -198,28 +198,6 @@ command_like(
],
qr/./,
'runs with start and end segment specified');
-command_fails_like(
- [ 'pg_waldump', '--path' => $node->data_dir ],
- qr/error: no start WAL location given/,
- 'path option requires start location');
-command_like(
- [
- 'pg_waldump',
- '--path' => $node->data_dir,
- '--start' => $start_lsn,
- '--end' => $end_lsn,
- ],
- qr/./,
- 'runs with path option and start and end locations');
-command_fails_like(
- [
- 'pg_waldump',
- '--path' => $node->data_dir,
- '--start' => $start_lsn,
- ],
- qr/error: error in WAL record at/,
- 'falling off the end of the WAL results in an error');
-
command_like(
[
'pg_waldump', '--quiet',
@@ -227,15 +205,6 @@ command_like(
],
qr/^$/,
'no output with --quiet option');
-command_fails_like(
- [
- 'pg_waldump', '--quiet',
- '--path' => $node->data_dir,
- '--start' => $start_lsn
- ],
- qr/error: error in WAL record at/,
- 'errors are shown with --quiet');
-
# Test for: Display a message that we're skipping data if `from`
# wasn't a pointer to the start of a record.
@@ -272,7 +241,6 @@ sub test_pg_waldump
my $result = IPC::Run::run [
'pg_waldump',
- '--path' => $node->data_dir,
'--start' => $start_lsn,
'--end' => $end_lsn,
@opts
@@ -288,38 +256,81 @@ sub test_pg_waldump
my @lines;
-@lines = test_pg_waldump;
-is(grep(!/^rmgr: \w/, @lines), 0, 'all output lines are rmgr lines');
+my @scenarios = (
+ {
+ 'path' => $node->data_dir
+ });
-@lines = test_pg_waldump('--limit' => 6);
-is(@lines, 6, 'limit option observed');
+for my $scenario (@scenarios)
+{
+ my $path = $scenario->{'path'};
-@lines = test_pg_waldump('--fullpage');
-is(grep(!/^rmgr:.*\bFPW\b/, @lines), 0, 'all output lines are FPW');
+ SKIP:
+ {
+ command_fails_like(
+ [ 'pg_waldump', '--path' => $path ],
+ qr/error: no start WAL location given/,
+ 'path option requires start location');
+ command_like(
+ [
+ 'pg_waldump',
+ '--path' => $path,
+ '--start' => $start_lsn,
+ '--end' => $end_lsn,
+ ],
+ qr/./,
+ 'runs with path option and start and end locations');
+ command_fails_like(
+ [
+ 'pg_waldump',
+ '--path' => $path,
+ '--start' => $start_lsn,
+ ],
+ qr/error: error in WAL record at/,
+ 'falling off the end of the WAL results in an error');
-@lines = test_pg_waldump('--stats');
-like($lines[0], qr/WAL statistics/, "statistics on stdout");
-is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
+ command_fails_like(
+ [
+ 'pg_waldump', '--quiet',
+ '--path' => $path,
+ '--start' => $start_lsn
+ ],
+ qr/error: error in WAL record at/,
+ 'errors are shown with --quiet');
-@lines = test_pg_waldump('--stats=record');
-like($lines[0], qr/WAL statistics/, "statistics on stdout");
-is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
+ @lines = test_pg_waldump('--path' => $path);
+ is(grep(!/^rmgr: \w/, @lines), 0, 'all output lines are rmgr lines');
-@lines = test_pg_waldump('--rmgr' => 'Btree');
-is(grep(!/^rmgr: Btree/, @lines), 0, 'only Btree lines');
+ @lines = test_pg_waldump('--path' => $path, '--limit' => 6);
+ is(@lines, 6, 'limit option observed');
-@lines = test_pg_waldump('--fork' => 'init');
-is(grep(!/fork init/, @lines), 0, 'only init fork lines');
+ @lines = test_pg_waldump('--path' => $path, '--fullpage');
+ is(grep(!/^rmgr:.*\bFPW\b/, @lines), 0, 'all output lines are FPW');
-@lines = test_pg_waldump(
- '--relation' => "$default_ts_oid/$postgres_db_oid/$rel_t1_oid");
-is(grep(!/rel $default_ts_oid\/$postgres_db_oid\/$rel_t1_oid/, @lines),
- 0, 'only lines for selected relation');
+ @lines = test_pg_waldump('--path' => $path, '--stats');
+ like($lines[0], qr/WAL statistics/, "statistics on stdout");
+ is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
-@lines = test_pg_waldump(
- '--relation' => "$default_ts_oid/$postgres_db_oid/$rel_i1a_oid",
- '--block' => 1);
-is(grep(!/\bblk 1\b/, @lines), 0, 'only lines for selected block');
+ @lines = test_pg_waldump('--path' => $path, '--stats=record');
+ like($lines[0], qr/WAL statistics/, "statistics on stdout");
+ is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
+ @lines = test_pg_waldump('--path' => $path, '--rmgr' => 'Btree');
+ is(grep(!/^rmgr: Btree/, @lines), 0, 'only Btree lines');
+
+ @lines = test_pg_waldump('--path' => $path, '--fork' => 'init');
+ is(grep(!/fork init/, @lines), 0, 'only init fork lines');
+
+ @lines = test_pg_waldump('--path' => $path,
+ '--relation' => "$default_ts_oid/$postgres_db_oid/$rel_t1_oid");
+ is(grep(!/rel $default_ts_oid\/$postgres_db_oid\/$rel_t1_oid/, @lines),
+ 0, 'only lines for selected relation');
+
+ @lines = test_pg_waldump('--path' => $path,
+ '--relation' => "$default_ts_oid/$postgres_db_oid/$rel_i1a_oid",
+ '--block' => 1);
+ is(grep(!/\bblk 1\b/, @lines), 0, 'only lines for selected block');
+ }
+}
done_testing();
--
2.47.1
[application/octet-stream] v10-0004-pg_waldump-Add-support-for-archived-WAL-decoding.patch (37.3K, 5-v10-0004-pg_waldump-Add-support-for-archived-WAL-decoding.patch)
download | inline diff:
From b8fba73c2abf78fd6972ac077b3d22332a4d477b Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Fri, 2 Jan 2026 17:07:34 +0530
Subject: [PATCH v10 4/8] pg_waldump: Add support for archived WAL decoding.
pg_waldump can now accept the path to a tar archive containing WAL
files and decode them. This feature was added primarily for
pg_verifybackup, which previously disabled WAL parsing for
tar-formatted backups.
Note that this patch requires that the WAL files within the archive be
in sequential order; an error will be reported otherwise. The next
patch is planned to remove this restriction.
---
doc/src/sgml/ref/pg_waldump.sgml | 8 +-
src/bin/pg_waldump/Makefile | 7 +-
src/bin/pg_waldump/archive_waldump.c | 594 +++++++++++++++++++++++++++
src/bin/pg_waldump/meson.build | 4 +-
src/bin/pg_waldump/pg_waldump.c | 218 +++++++---
src/bin/pg_waldump/pg_waldump.h | 34 ++
src/bin/pg_waldump/t/001_basic.pl | 84 +++-
src/tools/pgindent/typedefs.list | 3 +
8 files changed, 876 insertions(+), 76 deletions(-)
create mode 100644 src/bin/pg_waldump/archive_waldump.c
diff --git a/doc/src/sgml/ref/pg_waldump.sgml b/doc/src/sgml/ref/pg_waldump.sgml
index ce23add5577..d004bb0f67e 100644
--- a/doc/src/sgml/ref/pg_waldump.sgml
+++ b/doc/src/sgml/ref/pg_waldump.sgml
@@ -141,13 +141,17 @@ PostgreSQL documentation
<term><option>--path=<replaceable>path</replaceable></option></term>
<listitem>
<para>
- Specifies a directory to search for WAL segment files or a
- directory with a <literal>pg_wal</literal> subdirectory that
+ Specifies a tar archive or a directory to search for WAL segment files
+ or a directory with a <literal>pg_wal</literal> subdirectory that
contains such files. The default is to search in the current
directory, the <literal>pg_wal</literal> subdirectory of the
current directory, and the <literal>pg_wal</literal> subdirectory
of <envar>PGDATA</envar>.
</para>
+ <para>
+ If a tar archive is provided, its WAL segment files must be in
+ sequential order; otherwise, an error will be reported.
+ </para>
</listitem>
</varlistentry>
diff --git a/src/bin/pg_waldump/Makefile b/src/bin/pg_waldump/Makefile
index 4c1ee649501..aabb87566a2 100644
--- a/src/bin/pg_waldump/Makefile
+++ b/src/bin/pg_waldump/Makefile
@@ -3,6 +3,9 @@
PGFILEDESC = "pg_waldump - decode and display WAL"
PGAPPICON=win32
+# make these available to TAP test scripts
+export TAR
+
subdir = src/bin/pg_waldump
top_builddir = ../../..
include $(top_builddir)/src/Makefile.global
@@ -10,13 +13,15 @@ include $(top_builddir)/src/Makefile.global
OBJS = \
$(RMGRDESCOBJS) \
$(WIN32RES) \
+ archive_waldump.o \
compat.o \
pg_waldump.o \
rmgrdesc.o \
xlogreader.o \
xlogstats.o
-override CPPFLAGS := -DFRONTEND $(CPPFLAGS)
+override CPPFLAGS := -DFRONTEND -I$(libpq_srcdir) $(CPPFLAGS)
+LDFLAGS_INTERNAL += -L$(top_builddir)/src/fe_utils -lpgfeutils
RMGRDESCSOURCES = $(sort $(notdir $(wildcard $(top_srcdir)/src/backend/access/rmgrdesc/*desc*.c)))
RMGRDESCOBJS = $(patsubst %.c,%.o,$(RMGRDESCSOURCES))
diff --git a/src/bin/pg_waldump/archive_waldump.c b/src/bin/pg_waldump/archive_waldump.c
new file mode 100644
index 00000000000..6ba067163d5
--- /dev/null
+++ b/src/bin/pg_waldump/archive_waldump.c
@@ -0,0 +1,594 @@
+/*-------------------------------------------------------------------------
+ *
+ * archive_waldump.c
+ * A generic facility for reading WAL data from tar archives via archive
+ * streamer.
+ *
+ * Portions Copyright (c) 2026, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/bin/pg_waldump/archive_waldump.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres_fe.h"
+
+#include <unistd.h>
+
+#include "access/xlog_internal.h"
+#include "common/hashfn.h"
+#include "common/logging.h"
+#include "fe_utils/simple_list.h"
+#include "pg_waldump.h"
+
+/*
+ * How many bytes should we try to read from a file at once?
+ */
+#define READ_CHUNK_SIZE (128 * 1024)
+
+/* Hash entry structure for holding WAL segment data read from the archive */
+typedef struct ArchivedWALEntry
+{
+ uint32 status; /* hash status */
+ XLogSegNo segno; /* hash key: WAL segment number */
+ TimeLineID timeline; /* timeline of this wal file */
+
+ StringInfoData buf;
+ bool tmpseg_exists; /* spill file exists? */
+
+ int total_read; /* total read of archived WAL segment */
+} ArchivedWALEntry;
+
+#define SH_PREFIX ArchivedWAL
+#define SH_ELEMENT_TYPE ArchivedWALEntry
+#define SH_KEY_TYPE XLogSegNo
+#define SH_KEY segno
+#define SH_HASH_KEY(tb, key) murmurhash64((uint64) key)
+#define SH_EQUAL(tb, a, b) (a == b)
+#define SH_GET_HASH(tb, a) a->hash
+#define SH_SCOPE static inline
+#define SH_RAW_ALLOCATOR pg_malloc0
+#define SH_DECLARE
+#define SH_DEFINE
+#include "lib/simplehash.h"
+
+static ArchivedWAL_hash *ArchivedWAL_HTAB = NULL;
+
+typedef struct astreamer_waldump
+{
+ astreamer base;
+ XLogDumpPrivate *privateInfo;
+} astreamer_waldump;
+
+static int read_archive_file(XLogDumpPrivate *privateInfo, Size count);
+static ArchivedWALEntry *get_archive_wal_entry(XLogSegNo segno,
+ XLogDumpPrivate *privateInfo);
+
+static astreamer *astreamer_waldump_new(XLogDumpPrivate *privateInfo);
+static void astreamer_waldump_content(astreamer *streamer,
+ astreamer_member *member,
+ const char *data, int len,
+ astreamer_archive_context context);
+static void astreamer_waldump_finalize(astreamer *streamer);
+static void astreamer_waldump_free(astreamer *streamer);
+
+static bool member_is_wal_file(astreamer_waldump *mystreamer,
+ astreamer_member *member,
+ XLogSegNo *curSegNo,
+ TimeLineID *curTimeline);
+
+static const astreamer_ops astreamer_waldump_ops = {
+ .content = astreamer_waldump_content,
+ .finalize = astreamer_waldump_finalize,
+ .free = astreamer_waldump_free
+};
+
+/*
+ * Returns true if the given file is a tar archive and outputs its compression
+ * algorithm.
+ */
+bool
+is_archive_file(const char *fname, pg_compress_algorithm *compression)
+{
+ int fname_len = strlen(fname);
+ pg_compress_algorithm compress_algo;
+
+ /* Now, check the compression type of the tar */
+ if (fname_len > 4 &&
+ strcmp(fname + fname_len - 4, ".tar") == 0)
+ compress_algo = PG_COMPRESSION_NONE;
+ else if (fname_len > 4 &&
+ strcmp(fname + fname_len - 4, ".tgz") == 0)
+ compress_algo = PG_COMPRESSION_GZIP;
+ else if (fname_len > 7 &&
+ strcmp(fname + fname_len - 7, ".tar.gz") == 0)
+ compress_algo = PG_COMPRESSION_GZIP;
+ else if (fname_len > 8 &&
+ strcmp(fname + fname_len - 8, ".tar.lz4") == 0)
+ compress_algo = PG_COMPRESSION_LZ4;
+ else if (fname_len > 8 &&
+ strcmp(fname + fname_len - 8, ".tar.zst") == 0)
+ compress_algo = PG_COMPRESSION_ZSTD;
+ else
+ return false;
+
+ *compression = compress_algo;
+
+ return true;
+}
+
+/*
+ * Initializes the tar archive reader, creates a hash table for WAL entries,
+ * checks for existing valid WAL segments in the archive file and retrieves the
+ * segment size, and sets up filters for relevant entries.
+ */
+void
+init_archive_reader(XLogDumpPrivate *privateInfo, const char *waldir,
+ pg_compress_algorithm compression)
+{
+ int fd;
+ astreamer *streamer;
+ ArchivedWALEntry *entry = NULL;
+ XLogLongPageHeader longhdr;
+
+ /* Open tar archive and store its file descriptor */
+ fd = open_file_in_directory(waldir, privateInfo->archive_name);
+
+ if (fd < 0)
+ pg_fatal("could not open file \"%s\"", privateInfo->archive_name);
+
+ privateInfo->archive_fd = fd;
+
+ streamer = astreamer_waldump_new(privateInfo);
+
+ /* Before that we must parse the tar archive. */
+ streamer = astreamer_tar_parser_new(streamer);
+
+ /* Before that we must decompress, if archive is compressed. */
+ if (compression == PG_COMPRESSION_GZIP)
+ streamer = astreamer_gzip_decompressor_new(streamer);
+ else if (compression == PG_COMPRESSION_LZ4)
+ streamer = astreamer_lz4_decompressor_new(streamer);
+ else if (compression == PG_COMPRESSION_ZSTD)
+ streamer = astreamer_zstd_decompressor_new(streamer);
+
+ privateInfo->archive_streamer = streamer;
+
+ /* Hash table storing WAL entries read from the archive */
+ ArchivedWAL_HTAB = ArchivedWAL_create(16, NULL);
+
+ /*
+ * Verify that the archive contains valid WAL files and fetch WAL segment
+ * size
+ */
+ while (entry == NULL || entry->buf.len < XLOG_BLCKSZ)
+ {
+ if (read_archive_file(privateInfo, XLOG_BLCKSZ) == 0)
+ pg_fatal("could not find WAL in \"%s\" archive",
+ privateInfo->archive_name);
+
+ entry = privateInfo->cur_wal;
+ }
+
+ /* Set WalSegSz if WAL data is successfully read */
+ longhdr = (XLogLongPageHeader) entry->buf.data;
+
+ WalSegSz = longhdr->xlp_seg_size;
+
+ if (!IsValidWalSegSize(WalSegSz))
+ {
+ pg_log_error(ngettext("invalid WAL segment size in WAL file from archive \"%s\" (%d byte)",
+ "invalid WAL segment size in WAL file from archive \"%s\" (%d bytes)",
+ WalSegSz),
+ privateInfo->archive_name, WalSegSz);
+ pg_log_error_detail("The WAL segment size must be a power of two between 1 MB and 1 GB.");
+ exit(1);
+ }
+
+ /*
+ * With the WAL segment size available, we can now initialize the
+ * dependent start and end segment numbers.
+ */
+ Assert(!XLogRecPtrIsInvalid(privateInfo->startptr));
+ XLByteToSeg(privateInfo->startptr, privateInfo->startSegNo, WalSegSz);
+
+ if (XLogRecPtrIsInvalid(privateInfo->endptr))
+ privateInfo->endSegNo = UINT64_MAX;
+ else
+ XLByteToSeg(privateInfo->endptr, privateInfo->endSegNo, WalSegSz);
+}
+
+/*
+ * Release the archive streamer chain and close the archive file.
+ */
+void
+free_archive_reader(XLogDumpPrivate *privateInfo)
+{
+ /*
+ * NB: Normally, astreamer_finalize() is called before astreamer_free() to
+ * flush any remaining buffered data or to ensure the end of the tar
+ * archive is reached. However, when decoding a WAL file, once we hit the
+ * end LSN, any remaining WAL data in the buffer or the tar archive's
+ * unreached end can be safely ignored.
+ */
+ astreamer_free(privateInfo->archive_streamer);
+
+ /* Close the file. */
+ if (close(privateInfo->archive_fd) != 0)
+ pg_log_error("could not close file \"%s\": %m",
+ privateInfo->archive_name);
+}
+
+/*
+ * Copies WAL data from astreamer to readBuff; if unavailable, fetches more
+ * from the tar archive via astreamer.
+ */
+int
+read_archive_wal_page(XLogDumpPrivate *privateInfo, XLogRecPtr targetPagePtr,
+ Size count, char *readBuff)
+{
+ char *p = readBuff;
+ Size nbytes = count;
+ XLogRecPtr recptr = targetPagePtr;
+ XLogSegNo segno;
+ ArchivedWALEntry *entry;
+
+ XLByteToSeg(targetPagePtr, segno, WalSegSz);
+ entry = get_archive_wal_entry(segno, privateInfo);
+
+ while (nbytes > 0)
+ {
+ char *buf = entry->buf.data;
+ int len = entry->buf.len;
+
+ /* WAL record range that the buffer contains */
+ XLogRecPtr endPtr;
+ XLogRecPtr startPtr;
+
+ XLogSegNoOffsetToRecPtr(entry->segno, entry->total_read,
+ WalSegSz, endPtr);
+ startPtr = endPtr - len;
+
+ /*
+ * pg_waldump may request to re-read the currently active page, but
+ * never a page older than the current one. Therefore, any fully
+ * consumed WAL data preceding the current page can be safely
+ * discarded.
+ */
+ if (recptr >= endPtr)
+ {
+ /* Discard the buffered data */
+ resetStringInfo(&entry->buf);
+ len = 0;
+
+ /*
+ * Push back the partial page data for the current page to the
+ * buffer, ensuring it remains full page available for re-reading
+ * if requested.
+ */
+ if (p > readBuff)
+ {
+ Assert((count - nbytes) > 0);
+ appendBinaryStringInfo(&entry->buf, readBuff, count - nbytes);
+ }
+ }
+
+ if (len > 0 && recptr > startPtr)
+ {
+ int skipBytes = 0;
+
+ /*
+ * The required offset is not at the start of the buffer, so skip
+ * bytes until reaching the desired offset of the target page.
+ */
+ skipBytes = recptr - startPtr;
+
+ buf += skipBytes;
+ len -= skipBytes;
+ }
+
+ if (len > 0)
+ {
+ int readBytes = len >= nbytes ? nbytes : len;
+
+ /* Ensure the reading page is in the buffer */
+ Assert(recptr >= startPtr && recptr < endPtr);
+
+ memcpy(p, buf, readBytes);
+
+ /* Update state for read */
+ nbytes -= readBytes;
+ p += readBytes;
+ recptr += readBytes;
+ }
+ else
+ {
+ /*
+ * Fetch more data; raise an error if it's not the current segment
+ * being read by the archive streamer or if reading of the
+ * archived file has finished.
+ */
+ if (privateInfo->cur_wal != entry ||
+ read_archive_file(privateInfo, READ_CHUNK_SIZE) == 0)
+ {
+ char fname[MAXFNAMELEN];
+
+ XLogFileName(fname, privateInfo->timeline, entry->segno,
+ WalSegSz);
+ pg_fatal("could not read file \"%s\" from archive \"%s\": read %lld of %lld",
+ fname, privateInfo->archive_name,
+ (long long int) count - nbytes,
+ (long long int) nbytes);
+ }
+ }
+ }
+
+ /*
+ * Should have either have successfully read all the requested bytes or
+ * reported a failure before this point.
+ */
+ Assert(nbytes == 0);
+
+ /*
+ * NB: We return the fixed value provided as input. Although we could
+ * return a boolean since we either successfully read the WAL page or
+ * raise an error, but the caller expects this value to be returned. The
+ * routine that reads WAL pages from the physical WAL file follows the
+ * same convention.
+ */
+ return count;
+}
+
+/*
+ * Reads the archive file and passes it to the archive streamer for
+ * decompression.
+ */
+static int
+read_archive_file(XLogDumpPrivate *privateInfo, Size count)
+{
+ int rc;
+ char *buffer;
+
+ buffer = pg_malloc(READ_CHUNK_SIZE * sizeof(uint8));
+
+ rc = read(privateInfo->archive_fd, buffer, count);
+ if (rc < 0)
+ pg_fatal("could not read file \"%s\": %m",
+ privateInfo->archive_name);
+
+ /*
+ * Decompress (if required), and then parse the previously read contents
+ * of the tar file.
+ */
+ if (rc > 0)
+ astreamer_content(privateInfo->archive_streamer, NULL,
+ buffer, rc, ASTREAMER_UNKNOWN);
+ pg_free(buffer);
+
+ return rc;
+}
+
+/*
+ * Returns the archived WAL entry from the hash table if it exists. Otherwise,
+ * it invokes the routine to read the archived file, which then populates the
+ * entry in the hash table.
+ */
+static ArchivedWALEntry *
+get_archive_wal_entry(XLogSegNo segno, XLogDumpPrivate *privateInfo)
+{
+ ArchivedWALEntry *entry = NULL;
+ char fname[MAXFNAMELEN];
+
+ /* Search hash table */
+ entry = ArchivedWAL_lookup(ArchivedWAL_HTAB, segno);
+
+ if (entry != NULL)
+ return entry;
+
+ /* Needed WAL yet to be decoded from archive, do the same */
+ while (1)
+ {
+ entry = privateInfo->cur_wal;
+
+ /* Fetch more data */
+ if (read_archive_file(privateInfo, READ_CHUNK_SIZE) == 0)
+ break; /* archive file ended */
+
+ /*
+ * Either, here for the first time, or the archived streamer is
+ * reading a non-WAL file or an irrelevant WAL file.
+ */
+ if (entry == NULL)
+ continue;
+
+ /* Found the required entry */
+ if (entry->segno == segno)
+ return entry;
+
+ /*
+ * Ignore if the timeline is different or the current segment is not
+ * the desired one.
+ */
+ if (privateInfo->timeline != entry->timeline ||
+ privateInfo->startSegNo > entry->segno ||
+ privateInfo->endSegNo < entry->segno)
+ {
+ privateInfo->cur_wal = NULL;
+ continue;
+ }
+
+ /*
+ * XXX: If the segment being read not the requested one, the data must
+ * be buffered, as we currently lack the mechanism to write it to a
+ * temporary file. This is a known limitation that will be fixed in the
+ * next patch, as the buffer could grow up to the full WAL segment
+ * size.
+ */
+ if (segno > entry->segno)
+ continue;
+
+ /* WAL segments must be archived in order */
+ pg_log_error("WAL files are not archived in sequential order");
+ pg_log_error_detail("Expecting segment number " UINT64_FORMAT " but found " UINT64_FORMAT ".",
+ segno, entry->segno);
+ exit(1);
+ }
+
+ /* Requested WAL segment not found */
+ XLogFileName(fname, privateInfo->timeline, segno, WalSegSz);
+ pg_fatal("could not find file \"%s\" in archive", fname);
+}
+
+/*
+ * Create an astreamer that can read WAL from a tar file.
+ */
+static astreamer *
+astreamer_waldump_new(XLogDumpPrivate *privateInfo)
+{
+ astreamer_waldump *streamer;
+
+ streamer = palloc0(sizeof(astreamer_waldump));
+ *((const astreamer_ops **) &streamer->base.bbs_ops) =
+ &astreamer_waldump_ops;
+
+ streamer->privateInfo = privateInfo;
+
+ return &streamer->base;
+}
+
+/*
+ * Main entry point of the archive streamer for reading WAL data from a tar
+ * file. If a member is identified as a valid WAL file, a hash entry is created
+ * for it, and its contents are copied into that entry's buffer, making them
+ * accessible to the decoding routine.
+ */
+static void
+astreamer_waldump_content(astreamer *streamer, astreamer_member *member,
+ const char *data, int len,
+ astreamer_archive_context context)
+{
+ astreamer_waldump *mystreamer = (astreamer_waldump *) streamer;
+ XLogDumpPrivate *privateInfo = mystreamer->privateInfo;
+
+ Assert(context != ASTREAMER_UNKNOWN);
+
+ switch (context)
+ {
+ case ASTREAMER_MEMBER_HEADER:
+ {
+ XLogSegNo segno;
+ TimeLineID timeline;
+ ArchivedWALEntry *entry;
+ bool found;
+
+ pg_log_debug("reading \"%s\"", member->pathname);
+
+ if (!member_is_wal_file(mystreamer, member,
+ &segno, &timeline))
+ break;
+
+ entry = ArchivedWAL_insert(ArchivedWAL_HTAB, segno, &found);
+
+ /*
+ * Shouldn't happen, but if it does, simply ignore the
+ * duplicate WAL file.
+ */
+ if (found)
+ {
+ pg_log_warning("ignoring duplicate WAL file found in archive: \"%s\"",
+ member->pathname);
+ break;
+ }
+
+ initStringInfo(&entry->buf);
+ entry->timeline = timeline;
+ entry->total_read = 0;
+
+ privateInfo->cur_wal = entry;
+ }
+ break;
+
+ case ASTREAMER_MEMBER_CONTENTS:
+ if (privateInfo->cur_wal)
+ {
+ appendBinaryStringInfo(&privateInfo->cur_wal->buf, data, len);
+ privateInfo->cur_wal->total_read += len;
+ }
+ break;
+
+ case ASTREAMER_MEMBER_TRAILER:
+ privateInfo->cur_wal = NULL;
+ break;
+
+ case ASTREAMER_ARCHIVE_TRAILER:
+ break;
+
+ default:
+ /* Shouldn't happen. */
+ pg_fatal("unexpected state while parsing tar file");
+ }
+}
+
+/*
+ * End-of-stream processing for an astreamer_waldump stream.
+ */
+static void
+astreamer_waldump_finalize(astreamer *streamer)
+{
+ Assert(streamer->bbs_next == NULL);
+}
+
+/*
+ * Free memory associated with a astreamer_waldump stream.
+ */
+static void
+astreamer_waldump_free(astreamer *streamer)
+{
+ Assert(streamer->bbs_next == NULL);
+ pfree(streamer);
+}
+
+/*
+ * Returns true if the archive member name matches the WAL naming format. If
+ * successful, it also outputs the WAL segment number, and timeline.
+ */
+static bool
+member_is_wal_file(astreamer_waldump *mystreamer, astreamer_member *member,
+ XLogSegNo *curSegNo, TimeLineID *curTimeline)
+{
+ int pathlen;
+ XLogSegNo segNo;
+ TimeLineID timeline;
+ char *fname;
+
+ /* We are only interested in normal files. */
+ if (member->is_directory || member->is_link)
+ return false;
+
+ pathlen = strlen(member->pathname);
+ if (pathlen < XLOG_FNAME_LEN)
+ return false;
+
+ /* WAL file could be with full path */
+ fname = member->pathname + (pathlen - XLOG_FNAME_LEN);
+ if (!IsXLogFileName(fname))
+ return false;
+
+ /*
+ * XXX: On some systems (e.g., OpenBSD), the tar utility includes
+ * PaxHeaders when creating an archive. These are special entries that
+ * store extended metadata for the file entry immediately following them,
+ * and they share the exact same name as that file.
+ */
+ if (strstr(member->pathname, "PaxHeaders."))
+ return false;
+
+ /* Parse position from file */
+ XLogFromFileName(fname, &timeline, &segNo, WalSegSz);
+
+ *curSegNo = segNo;
+ *curTimeline = timeline;
+
+ return true;
+}
diff --git a/src/bin/pg_waldump/meson.build b/src/bin/pg_waldump/meson.build
index 633a9874bb5..a93bd947ca2 100644
--- a/src/bin/pg_waldump/meson.build
+++ b/src/bin/pg_waldump/meson.build
@@ -1,6 +1,7 @@
# Copyright (c) 2022-2026, PostgreSQL Global Development Group
pg_waldump_sources = files(
+ 'archive_waldump.c',
'compat.c',
'pg_waldump.c',
'rmgrdesc.c',
@@ -18,7 +19,7 @@ endif
pg_waldump = executable('pg_waldump',
pg_waldump_sources,
- dependencies: [frontend_code, lz4, zstd],
+ dependencies: [frontend_code, lz4, zstd, libpq],
c_args: ['-DFRONTEND'], # needed for xlogreader et al
kwargs: default_bin_args,
)
@@ -29,6 +30,7 @@ tests += {
'sd': meson.current_source_dir(),
'bd': meson.current_build_dir(),
'tap': {
+ 'env': {'TAR': tar.found() ? tar.full_path() : ''},
'tests': [
't/001_basic.pl',
't/002_save_fullpage.pl',
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index a33fc28b9d5..e2c96c3f4ca 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -38,7 +38,7 @@
* give a thought about doing the same in pg_walinspect contrib module as well.
*/
-int WalSegSz;
+int WalSegSz = DEFAULT_XLOG_SEG_SIZE;
static const char *progname;
@@ -178,7 +178,7 @@ split_path(const char *path, char **dir, char **fname)
*
* return a read only fd
*/
-static int
+int
open_file_in_directory(const char *directory, const char *fname)
{
int fd = -1;
@@ -444,6 +444,45 @@ WALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
return count;
}
+/*
+ * pg_waldump's XLogReaderRoutine->segment_open callback to support dumping WAL
+ * files from tar archives.
+ */
+static void
+TarWALDumpOpenSegment(XLogReaderState *state, XLogSegNo nextSegNo,
+ TimeLineID *tli_p)
+{
+ /* No action needed */
+}
+
+/*
+ * pg_waldump's XLogReaderRoutine->segment_close callback.
+ */
+static void
+TarWALDumpCloseSegment(XLogReaderState *state)
+{
+ /* No action needed */
+}
+
+/*
+ * pg_waldump's XLogReaderRoutine->page_read callback to support dumping WAL
+ * files from tar archives.
+ */
+static int
+TarWALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
+ XLogRecPtr targetPtr, char *readBuff)
+{
+ XLogDumpPrivate *private = state->private_data;
+ int count = required_read_len(private, targetPagePtr, reqLen);
+
+ /* Bail out if the count to be read is not valid */
+ if (count < 0)
+ return -1;
+
+ /* Read the WAL page from the archive streamer */
+ return read_archive_wal_page(private, targetPagePtr, count, readBuff);
+}
+
/*
* Boolean to return whether the given WAL record matches a specific relation
* and optionally block.
@@ -781,8 +820,8 @@ usage(void)
printf(_(" -F, --fork=FORK only show records that modify blocks in fork FORK;\n"
" valid names are main, fsm, vm, init\n"));
printf(_(" -n, --limit=N number of records to display\n"));
- printf(_(" -p, --path=PATH directory in which to find WAL segment files or a\n"
- " directory with a ./pg_wal that contains such files\n"
+ printf(_(" -p, --path=PATH tar archive or a directory in which to find WAL segment files or\n"
+ " a directory with a ./pg_wal that contains such files\n"
" (default: current directory, ./pg_wal, $PGDATA/pg_wal)\n"));
printf(_(" -q, --quiet do not print any output, except for errors\n"));
printf(_(" -r, --rmgr=RMGR only show records generated by resource manager RMGR;\n"
@@ -814,7 +853,10 @@ main(int argc, char **argv)
XLogRecord *record;
XLogRecPtr first_record;
char *waldir = NULL;
+ char *walpath = NULL;
char *errormsg;
+ bool is_archive = false;
+ pg_compress_algorithm compression;
static struct option long_options[] = {
{"bkp-details", no_argument, NULL, 'b'},
@@ -946,7 +988,7 @@ main(int argc, char **argv)
}
break;
case 'p':
- waldir = pg_strdup(optarg);
+ walpath = pg_strdup(optarg);
break;
case 'q':
config.quiet = true;
@@ -1110,10 +1152,20 @@ main(int argc, char **argv)
goto bad_argument;
}
- if (waldir != NULL)
+ if (walpath != NULL)
{
+ /* validate path points to tar archive */
+ if (is_archive_file(walpath, &compression))
+ {
+ char *fname = NULL;
+
+ split_path(walpath, &waldir, &fname);
+
+ private.archive_name = fname;
+ is_archive = true;
+ }
/* validate path points to directory */
- if (!verify_directory(waldir))
+ else if (!verify_directory(walpath))
{
pg_log_error("could not open directory \"%s\": %m", waldir);
goto bad_argument;
@@ -1131,6 +1183,17 @@ main(int argc, char **argv)
int fd;
XLogSegNo segno;
+ /*
+ * If a tar archive is passed using the --path option, all other
+ * arguments become unnecessary.
+ */
+ if (is_archive)
+ {
+ pg_log_error("unnecessary command-line arguments specified with tar archive (first is \"%s\")",
+ argv[optind]);
+ goto bad_argument;
+ }
+
split_path(argv[optind], &directory, &fname);
if (waldir == NULL && directory != NULL)
@@ -1141,69 +1204,77 @@ main(int argc, char **argv)
pg_fatal("could not open directory \"%s\": %m", waldir);
}
- waldir = identify_target_directory(waldir, fname);
- fd = open_file_in_directory(waldir, fname);
- if (fd < 0)
- pg_fatal("could not open file \"%s\"", fname);
- close(fd);
-
- /* parse position from file */
- XLogFromFileName(fname, &private.timeline, &segno, WalSegSz);
-
- if (!XLogRecPtrIsValid(private.startptr))
- XLogSegNoOffsetToRecPtr(segno, 0, WalSegSz, private.startptr);
- else if (!XLByteInSeg(private.startptr, segno, WalSegSz))
+ if (fname != NULL && is_archive_file(fname, &compression))
{
- pg_log_error("start WAL location %X/%08X is not inside file \"%s\"",
- LSN_FORMAT_ARGS(private.startptr),
- fname);
- goto bad_argument;
+ private.archive_name = fname;
+ is_archive = true;
}
-
- /* no second file specified, set end position */
- if (!(optind + 1 < argc) && !XLogRecPtrIsValid(private.endptr))
- XLogSegNoOffsetToRecPtr(segno + 1, 0, WalSegSz, private.endptr);
-
- /* parse ENDSEG if passed */
- if (optind + 1 < argc)
+ else
{
- XLogSegNo endsegno;
-
- /* ignore directory, already have that */
- split_path(argv[optind + 1], &directory, &fname);
-
+ waldir = identify_target_directory(waldir, fname);
fd = open_file_in_directory(waldir, fname);
if (fd < 0)
pg_fatal("could not open file \"%s\"", fname);
close(fd);
/* parse position from file */
- XLogFromFileName(fname, &private.timeline, &endsegno, WalSegSz);
+ XLogFromFileName(fname, &private.timeline, &segno, WalSegSz);
- if (endsegno < segno)
- pg_fatal("ENDSEG %s is before STARTSEG %s",
- argv[optind + 1], argv[optind]);
+ if (!XLogRecPtrIsValid(private.startptr))
+ XLogSegNoOffsetToRecPtr(segno, 0, WalSegSz, private.startptr);
+ else if (!XLByteInSeg(private.startptr, segno, WalSegSz))
+ {
+ pg_log_error("start WAL location %X/%08X is not inside file \"%s\"",
+ LSN_FORMAT_ARGS(private.startptr),
+ fname);
+ goto bad_argument;
+ }
- if (!XLogRecPtrIsValid(private.endptr))
- XLogSegNoOffsetToRecPtr(endsegno + 1, 0, WalSegSz,
- private.endptr);
+ /* no second file specified, set end position */
+ if (!(optind + 1 < argc) && !XLogRecPtrIsValid(private.endptr))
+ XLogSegNoOffsetToRecPtr(segno + 1, 0, WalSegSz, private.endptr);
- /* set segno to endsegno for check of --end */
- segno = endsegno;
- }
+ /* parse ENDSEG if passed */
+ if (optind + 1 < argc)
+ {
+ XLogSegNo endsegno;
+ /* ignore directory, already have that */
+ split_path(argv[optind + 1], &directory, &fname);
- if (!XLByteInSeg(private.endptr, segno, WalSegSz) &&
- private.endptr != (segno + 1) * WalSegSz)
- {
- pg_log_error("end WAL location %X/%08X is not inside file \"%s\"",
- LSN_FORMAT_ARGS(private.endptr),
- argv[argc - 1]);
- goto bad_argument;
+ fd = open_file_in_directory(waldir, fname);
+ if (fd < 0)
+ pg_fatal("could not open file \"%s\"", fname);
+ close(fd);
+
+ /* parse position from file */
+ XLogFromFileName(fname, &private.timeline, &endsegno, WalSegSz);
+
+ if (endsegno < segno)
+ pg_fatal("ENDSEG %s is before STARTSEG %s",
+ argv[optind + 1], argv[optind]);
+
+ if (!XLogRecPtrIsValid(private.endptr))
+ XLogSegNoOffsetToRecPtr(endsegno + 1, 0, WalSegSz,
+ private.endptr);
+
+ /* set segno to endsegno for check of --end */
+ segno = endsegno;
+ }
+
+
+ if (!XLByteInSeg(private.endptr, segno, WalSegSz) &&
+ private.endptr != (segno + 1) * WalSegSz)
+ {
+ pg_log_error("end WAL location %X/%08X is not inside file \"%s\"",
+ LSN_FORMAT_ARGS(private.endptr),
+ argv[argc - 1]);
+ goto bad_argument;
+ }
}
}
- else
- waldir = identify_target_directory(waldir, NULL);
+ else if (!is_archive)
+ waldir = identify_target_directory(walpath, NULL);
/* we don't know what to print */
if (!XLogRecPtrIsValid(private.startptr))
@@ -1215,12 +1286,36 @@ main(int argc, char **argv)
/* done with argument parsing, do the actual work */
/* we have everything we need, start reading */
- xlogreader_state =
- XLogReaderAllocate(WalSegSz, waldir,
- XL_ROUTINE(.page_read = WALDumpReadPage,
- .segment_open = WALDumpOpenSegment,
- .segment_close = WALDumpCloseSegment),
- &private);
+ if (is_archive)
+ {
+ /*
+ * A NULL WAL directory indicates that the archive file is located in
+ * the current working directory of the pg_waldump execution
+ */
+ waldir = waldir ? pg_strdup(waldir) : pg_strdup(".");
+
+ /* Set up for reading tar file */
+ init_archive_reader(&private, waldir, compression);
+
+ /* Routine to decode WAL files in tar archive */
+ xlogreader_state =
+ XLogReaderAllocate(WalSegSz, waldir,
+ XL_ROUTINE(.page_read = TarWALDumpReadPage,
+ .segment_open = TarWALDumpOpenSegment,
+ .segment_close = TarWALDumpCloseSegment),
+ &private);
+ }
+ else
+ {
+ /* Routine to decode WAL files */
+ xlogreader_state =
+ XLogReaderAllocate(WalSegSz, waldir,
+ XL_ROUTINE(.page_read = WALDumpReadPage,
+ .segment_open = WALDumpOpenSegment,
+ .segment_close = WALDumpCloseSegment),
+ &private);
+ }
+
if (!xlogreader_state)
pg_fatal("out of memory while allocating a WAL reading processor");
@@ -1329,6 +1424,9 @@ main(int argc, char **argv)
XLogReaderFree(xlogreader_state);
+ if (is_archive)
+ free_archive_reader(&private);
+
return EXIT_SUCCESS;
bad_argument:
diff --git a/src/bin/pg_waldump/pg_waldump.h b/src/bin/pg_waldump/pg_waldump.h
index 926d529f9d6..ec7a33d40e0 100644
--- a/src/bin/pg_waldump/pg_waldump.h
+++ b/src/bin/pg_waldump/pg_waldump.h
@@ -12,9 +12,13 @@
#define PG_WALDUMP_H
#include "access/xlogdefs.h"
+#include "fe_utils/astreamer.h"
extern int WalSegSz;
+/* Forward declaration */
+struct ArchivedWALEntry;
+
/* Contains the necessary information to drive WAL decoding */
typedef struct XLogDumpPrivate
{
@@ -22,6 +26,36 @@ typedef struct XLogDumpPrivate
XLogRecPtr startptr;
XLogRecPtr endptr;
bool endptr_reached;
+
+ /* Fields required to read WAL from archive */
+ char *archive_name; /* Tar archive name */
+ int archive_fd; /* File descriptor for the open tar file */
+
+ astreamer *archive_streamer;
+
+ /* What the archive streamer is currently reading */
+ struct ArchivedWALEntry *cur_wal;
+
+ /*
+ * Although these values can be easily derived from startptr and endptr,
+ * doing so repeatedly for each archived member would be inefficient, as
+ * it would involve recalculating and filtering out irrelevant WAL
+ * segments.
+ */
+ XLogSegNo startSegNo;
+ XLogSegNo endSegNo;
} XLogDumpPrivate;
+extern int open_file_in_directory(const char *directory, const char *fname);
+
+extern bool is_archive_file(const char *fname,
+ pg_compress_algorithm *compression);
+extern void init_archive_reader(XLogDumpPrivate *privateInfo,
+ const char *waldir,
+ pg_compress_algorithm compression);
+extern void free_archive_reader(XLogDumpPrivate *privateInfo);
+extern int read_archive_wal_page(XLogDumpPrivate *privateInfo,
+ XLogRecPtr targetPagePtr,
+ Size count, char *readBuff);
+
#endif /* end of PG_WALDUMP_H */
diff --git a/src/bin/pg_waldump/t/001_basic.pl b/src/bin/pg_waldump/t/001_basic.pl
index 3288fadcf48..13567fbdba1 100644
--- a/src/bin/pg_waldump/t/001_basic.pl
+++ b/src/bin/pg_waldump/t/001_basic.pl
@@ -3,10 +3,13 @@
use strict;
use warnings FATAL => 'all';
+use Cwd;
use PostgreSQL::Test::Cluster;
use PostgreSQL::Test::Utils;
use Test::More;
+my $tar = $ENV{TAR};
+
program_help_ok('pg_waldump');
program_version_ok('pg_waldump');
program_options_handling_ok('pg_waldump');
@@ -235,7 +238,7 @@ command_like(
sub test_pg_waldump
{
local $Test::Builder::Level = $Test::Builder::Level + 1;
- my @opts = @_;
+ my ($path, @opts) = @_;
my ($stdout, $stderr);
@@ -243,6 +246,7 @@ sub test_pg_waldump
'pg_waldump',
'--start' => $start_lsn,
'--end' => $end_lsn,
+ '--path' => $path,
@opts
],
'>' => \$stdout,
@@ -254,11 +258,50 @@ sub test_pg_waldump
return @lines;
}
-my @lines;
+# Create a tar archive, sorting the file order
+sub generate_archive
+{
+ my ($archive, $directory, $compression_flags) = @_;
+
+ my @files;
+ opendir my $dh, $directory or die "opendir: $!";
+ while (my $entry = readdir $dh) {
+ # Skip '.' and '..'
+ next if $entry eq '.' || $entry eq '..';
+ push @files, $entry;
+ }
+ closedir $dh;
+
+ @files = sort @files;
+
+ # move into the WAL directory before archiving files
+ my $cwd = getcwd;
+ chdir($directory) || die "chdir: $!";
+ command_ok([$tar, $compression_flags, $archive, @files]);
+ chdir($cwd) || die "chdir: $!";
+}
+
+my $tmp_dir = PostgreSQL::Test::Utils::tempdir_short();
my @scenarios = (
{
- 'path' => $node->data_dir
+ 'path' => $node->data_dir,
+ 'is_archive' => 0,
+ 'enabled' => 1
+ },
+ {
+ 'path' => "$tmp_dir/pg_wal.tar",
+ 'compression_method' => 'none',
+ 'compression_flags' => '-cf',
+ 'is_archive' => 1,
+ 'enabled' => 1
+ },
+ {
+ 'path' => "$tmp_dir/pg_wal.tar.gz",
+ 'compression_method' => 'gzip',
+ 'compression_flags' => '-czf',
+ 'is_archive' => 1,
+ 'enabled' => check_pg_config("#define HAVE_LIBZ 1")
});
for my $scenario (@scenarios)
@@ -267,6 +310,19 @@ for my $scenario (@scenarios)
SKIP:
{
+ skip "tar command is not available", 3
+ if !defined $tar;
+ skip "$scenario->{'compression_method'} compression not supported by this build", 3
+ if !$scenario->{'enabled'} && $scenario->{'is_archive'};
+
+ # create pg_wal archive
+ if ($scenario->{'is_archive'})
+ {
+ generate_archive($path,
+ $node->data_dir . '/pg_wal',
+ $scenario->{'compression_flags'});
+ }
+
command_fails_like(
[ 'pg_waldump', '--path' => $path ],
qr/error: no start WAL location given/,
@@ -298,38 +354,42 @@ for my $scenario (@scenarios)
qr/error: error in WAL record at/,
'errors are shown with --quiet');
- @lines = test_pg_waldump('--path' => $path);
+ my @lines;
+ @lines = test_pg_waldump($path);
is(grep(!/^rmgr: \w/, @lines), 0, 'all output lines are rmgr lines');
- @lines = test_pg_waldump('--path' => $path, '--limit' => 6);
+ @lines = test_pg_waldump($path, '--limit' => 6);
is(@lines, 6, 'limit option observed');
- @lines = test_pg_waldump('--path' => $path, '--fullpage');
+ @lines = test_pg_waldump($path, '--fullpage');
is(grep(!/^rmgr:.*\bFPW\b/, @lines), 0, 'all output lines are FPW');
- @lines = test_pg_waldump('--path' => $path, '--stats');
+ @lines = test_pg_waldump($path, '--stats');
like($lines[0], qr/WAL statistics/, "statistics on stdout");
is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
- @lines = test_pg_waldump('--path' => $path, '--stats=record');
+ @lines = test_pg_waldump($path, '--stats=record');
like($lines[0], qr/WAL statistics/, "statistics on stdout");
is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
- @lines = test_pg_waldump('--path' => $path, '--rmgr' => 'Btree');
+ @lines = test_pg_waldump($path, '--rmgr' => 'Btree');
is(grep(!/^rmgr: Btree/, @lines), 0, 'only Btree lines');
- @lines = test_pg_waldump('--path' => $path, '--fork' => 'init');
+ @lines = test_pg_waldump($path, '--fork' => 'init');
is(grep(!/fork init/, @lines), 0, 'only init fork lines');
- @lines = test_pg_waldump('--path' => $path,
+ @lines = test_pg_waldump($path,
'--relation' => "$default_ts_oid/$postgres_db_oid/$rel_t1_oid");
is(grep(!/rel $default_ts_oid\/$postgres_db_oid\/$rel_t1_oid/, @lines),
0, 'only lines for selected relation');
- @lines = test_pg_waldump('--path' => $path,
+ @lines = test_pg_waldump($path,
'--relation' => "$default_ts_oid/$postgres_db_oid/$rel_i1a_oid",
'--block' => 1);
is(grep(!/\bblk 1\b/, @lines), 0, 'only lines for selected block');
+
+ # Cleanup.
+ unlink $path if $scenario->{'is_archive'};
}
}
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b9e671fcda8..b0d73743cea 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -144,6 +144,8 @@ ArchiveOpts
ArchiveShutdownCB
ArchiveStartupCB
ArchiveStreamState
+ArchivedWALEntry
+ArchivedWAL_hash
ArchiverOutput
ArchiverStage
ArrayAnalyzeExtraData
@@ -3495,6 +3497,7 @@ astreamer_recovery_injector
astreamer_tar_archiver
astreamer_tar_parser
astreamer_verify
+astreamer_waldump
astreamer_zstd_frame
auth_password_hook_typ
autovac_table
--
2.47.1
[application/octet-stream] v10-0005-pg_waldump-Remove-the-restriction-on-the-order-o.patch (13.3K, 6-v10-0005-pg_waldump-Remove-the-restriction-on-the-order-o.patch)
download | inline diff:
From c2811b147d50a7e2e8f6566344e9f1f85614560d Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Thu, 6 Nov 2025 13:48:33 +0530
Subject: [PATCH v10 5/8] pg_waldump: Remove the restriction on the order of
archived WAL files.
With previous patch, pg_waldump would stop decoding if WAL files were
not in the required sequence. With this patch, decoding will now
continue. Any WAL file that is out of order will be written to a
temporary location, from which it will be read later. Once a temporary
file has been read, it will be removed.
---
doc/src/sgml/ref/pg_waldump.sgml | 8 +-
src/bin/pg_waldump/archive_waldump.c | 230 ++++++++++++++++++++++++---
src/bin/pg_waldump/pg_waldump.c | 41 ++++-
src/bin/pg_waldump/pg_waldump.h | 4 +
src/bin/pg_waldump/t/001_basic.pl | 3 +-
5 files changed, 264 insertions(+), 22 deletions(-)
diff --git a/doc/src/sgml/ref/pg_waldump.sgml b/doc/src/sgml/ref/pg_waldump.sgml
index d004bb0f67e..27adf77755c 100644
--- a/doc/src/sgml/ref/pg_waldump.sgml
+++ b/doc/src/sgml/ref/pg_waldump.sgml
@@ -149,8 +149,12 @@ PostgreSQL documentation
of <envar>PGDATA</envar>.
</para>
<para>
- If a tar archive is provided, its WAL segment files must be in
- sequential order; otherwise, an error will be reported.
+ If a tar archive is provided and its WAL segment files are not in
+ sequential order, those files will be written to a temporary directory
+ named starting with <filename>waldump_tmp</filename>. This directory will be
+ created inside the directory specified by the <envar>TMPDIR</envar>
+ environment variable if it is set; otherwise, it will be created within
+ the same directory as the tar archive.
</para>
</listitem>
</varlistentry>
diff --git a/src/bin/pg_waldump/archive_waldump.c b/src/bin/pg_waldump/archive_waldump.c
index 6ba067163d5..aa64da9a57d 100644
--- a/src/bin/pg_waldump/archive_waldump.c
+++ b/src/bin/pg_waldump/archive_waldump.c
@@ -17,6 +17,7 @@
#include <unistd.h>
#include "access/xlog_internal.h"
+#include "common/file_perm.h"
#include "common/hashfn.h"
#include "common/logging.h"
#include "fe_utils/simple_list.h"
@@ -27,6 +28,9 @@
*/
#define READ_CHUNK_SIZE (128 * 1024)
+/* Temporary exported WAL file directory */
+static char *TmpWalSegDir = NULL;
+
/* Hash entry structure for holding WAL segment data read from the archive */
typedef struct ArchivedWALEntry
{
@@ -64,6 +68,11 @@ typedef struct astreamer_waldump
static int read_archive_file(XLogDumpPrivate *privateInfo, Size count);
static ArchivedWALEntry *get_archive_wal_entry(XLogSegNo segno,
XLogDumpPrivate *privateInfo);
+static void setup_tmpseg_dir(const char *waldir);
+static void cleanup_tmpseg_dir_atexit(void);
+
+static FILE *prepare_tmp_write(XLogSegNo segno);
+static void perform_tmp_write(XLogSegNo segno, StringInfo buf, FILE *file);
static astreamer *astreamer_waldump_new(XLogDumpPrivate *privateInfo);
static void astreamer_waldump_content(astreamer *streamer,
@@ -121,7 +130,9 @@ is_archive_file(const char *fname, pg_compress_algorithm *compression)
/*
* Initializes the tar archive reader, creates a hash table for WAL entries,
* checks for existing valid WAL segments in the archive file and retrieves the
- * segment size, and sets up filters for relevant entries.
+ * segment size, and sets up filters for relevant entries. It also configures a
+ * temporary directory for out-of-order WAL data and registers an exit callback
+ * to clean up temporary files.
*/
void
init_archive_reader(XLogDumpPrivate *privateInfo, const char *waldir,
@@ -197,6 +208,13 @@ init_archive_reader(XLogDumpPrivate *privateInfo, const char *waldir,
privateInfo->endSegNo = UINT64_MAX;
else
XLByteToSeg(privateInfo->endptr, privateInfo->endSegNo, WalSegSz);
+
+ /*
+ * Setup temporary directory to store WAL segments and set up an exit
+ * callback to remove it upon completion.
+ */
+ setup_tmpseg_dir(waldir);
+ atexit(cleanup_tmpseg_dir_atexit);
}
/*
@@ -370,15 +388,18 @@ read_archive_file(XLogDumpPrivate *privateInfo, Size count)
}
/*
- * Returns the archived WAL entry from the hash table if it exists. Otherwise,
+ * Returns the archived WAL entry from the hash table if it exists. Otherwise,
* it invokes the routine to read the archived file, which then populates the
- * entry in the hash table.
+ * entry in the hash table. If the archive streamer happens to be reading a
+ * WAL from archive file that is not currently needed, that WAL data is written
+ * to a temporary file.
*/
static ArchivedWALEntry *
get_archive_wal_entry(XLogSegNo segno, XLogDumpPrivate *privateInfo)
{
ArchivedWALEntry *entry = NULL;
char fname[MAXFNAMELEN];
+ FILE *write_fp = NULL;
/* Search hash table */
entry = ArchivedWAL_lookup(ArchivedWAL_HTAB, segno);
@@ -392,8 +413,11 @@ get_archive_wal_entry(XLogSegNo segno, XLogDumpPrivate *privateInfo)
entry = privateInfo->cur_wal;
/* Fetch more data */
- if (read_archive_file(privateInfo, READ_CHUNK_SIZE) == 0)
- break; /* archive file ended */
+ if (entry == NULL || entry->buf.len == 0)
+ {
+ if (read_archive_file(privateInfo, READ_CHUNK_SIZE) == 0)
+ break; /* archive file ended */
+ }
/*
* Either, here for the first time, or the archived streamer is
@@ -419,20 +443,31 @@ get_archive_wal_entry(XLogSegNo segno, XLogDumpPrivate *privateInfo)
}
/*
- * XXX: If the segment being read not the requested one, the data must
- * be buffered, as we currently lack the mechanism to write it to a
- * temporary file. This is a known limitation that will be fixed in the
- * next patch, as the buffer could grow up to the full WAL segment
- * size.
+ * Archive streamer is currently reading a file that isn't the one
+ * asked for, but it's required in the future. It should be written to
+ * a temporary location for retrieval when needed.
*/
- if (segno > entry->segno)
- continue;
- /* WAL segments must be archived in order */
- pg_log_error("WAL files are not archived in sequential order");
- pg_log_error_detail("Expecting segment number " UINT64_FORMAT " but found " UINT64_FORMAT ".",
- segno, entry->segno);
- exit(1);
+ /* Create a temporary file if one does not already exist */
+ if (!entry->tmpseg_exists)
+ {
+ write_fp = prepare_tmp_write(entry->segno);
+ entry->tmpseg_exists = true;
+ }
+
+ /* Flush data from the buffer to the file */
+ perform_tmp_write(entry->segno, &entry->buf, write_fp);
+ resetStringInfo(&entry->buf);
+
+ /*
+ * The change in the current segment entry indicates that the reading
+ * of this file has ended.
+ */
+ if (entry != privateInfo->cur_wal && write_fp != NULL)
+ {
+ fclose(write_fp);
+ write_fp = NULL;
+ }
}
/* Requested WAL segment not found */
@@ -441,7 +476,166 @@ get_archive_wal_entry(XLogSegNo segno, XLogDumpPrivate *privateInfo)
}
/*
- * Create an astreamer that can read WAL from a tar file.
+ * Set up a temporary directory to temporarily store WAL segments.
+ */
+static void
+setup_tmpseg_dir(const char *waldir)
+{
+ char *template;
+
+ /*
+ * Use the directory specified by the TMPDIR environment variable. If it's
+ * not set, use the provided WAL directory to extract WAL file
+ * temporarily.
+ */
+ template = psprintf("%s/waldump_tmp-XXXXXX",
+ getenv("TMPDIR") ? getenv("TMPDIR") : waldir);
+ TmpWalSegDir = mkdtemp(template);
+
+ if (TmpWalSegDir == NULL)
+ pg_fatal("could not create directory \"%s\": %m", template);
+
+ canonicalize_path(TmpWalSegDir);
+
+ pg_log_debug("created directory \"%s\"", TmpWalSegDir);
+}
+
+/*
+ * Removes the temporarily store WAL segments, if any, at exiting.
+ */
+static void
+cleanup_tmpseg_dir_atexit(void)
+{
+ ArchivedWAL_iterator it;
+ ArchivedWALEntry *entry;
+
+ /* Remove temporary segments */
+ ArchivedWAL_start_iterate(ArchivedWAL_HTAB, &it);
+ while ((entry = ArchivedWAL_iterate(ArchivedWAL_HTAB, &it)) != NULL)
+ {
+ if (entry->tmpseg_exists)
+ {
+ remove_tmp_walseg(entry->segno, false);
+ entry->tmpseg_exists = false;
+ }
+ }
+
+ /* Remove temporary directory */
+ if (rmdir(TmpWalSegDir) == 0)
+ pg_log_debug("removed directory \"%s\"", TmpWalSegDir);
+}
+
+/*
+ * Generate the temporary WAL file path.
+ *
+ * Note that the caller is responsible to pfree it.
+ */
+char *
+get_tmp_walseg_path(XLogSegNo segno)
+{
+ char *fpath = (char *) palloc(MAXPGPATH);
+
+ Assert(TmpWalSegDir);
+
+ snprintf(fpath, MAXPGPATH, "%s/%08X%08X",
+ TmpWalSegDir,
+ (uint32) (segno / XLogSegmentsPerXLogId(WalSegSz)),
+ (uint32) (segno % XLogSegmentsPerXLogId(WalSegSz)));
+
+ return fpath;
+}
+
+/*
+ * Routine to check whether a temporary file exists for the corresponding WAL
+ * segment number.
+ */
+bool
+tmp_walseg_exists(XLogSegNo segno)
+{
+ ArchivedWALEntry *entry;
+
+ entry = ArchivedWAL_lookup(ArchivedWAL_HTAB, segno);
+
+ if (entry == NULL)
+ return false;
+
+ return entry->tmpseg_exists;
+}
+
+/*
+ * Create an empty placeholder file and return its handle.
+ */
+static FILE *
+prepare_tmp_write(XLogSegNo segno)
+{
+ FILE *file;
+ char *fpath;
+
+ fpath = get_tmp_walseg_path(segno);
+
+ /* Create an empty placeholder */
+ file = fopen(fpath, PG_BINARY_W);
+ if (file == NULL)
+ pg_fatal("could not create file \"%s\": %m", fpath);
+
+#ifndef WIN32
+ if (chmod(fpath, pg_file_create_mode))
+ pg_fatal("could not set permissions on file \"%s\": %m",
+ fpath);
+#endif
+
+ pg_log_debug("temporarily exporting file \"%s\"", fpath);
+ pfree(fpath);
+
+ return file;
+}
+
+/*
+ * Write buffer data to the given file handle.
+ */
+static void
+perform_tmp_write(XLogSegNo segno, StringInfo buf, FILE *file)
+{
+ Assert(file);
+
+ errno = 0;
+ if (buf->len > 0 && fwrite(buf->data, buf->len, 1, file) != 1)
+ {
+ /*
+ * If write didn't set errno, assume problem is no disk space
+ */
+ if (errno == 0)
+ errno = ENOSPC;
+ pg_fatal("could not write to file \"%s\": %m",
+ get_tmp_walseg_path(segno));
+ }
+}
+
+/*
+ * Remove temporary file
+ */
+void
+remove_tmp_walseg(XLogSegNo segno, bool update_entry)
+{
+ char *fpath = get_tmp_walseg_path(segno);
+
+ if (unlink(fpath) == 0)
+ pg_log_debug("removed file \"%s\"", fpath);
+ pfree(fpath);
+
+ /* Update entry if requested */
+ if (update_entry)
+ {
+ ArchivedWALEntry *entry;
+
+ entry = ArchivedWAL_lookup(ArchivedWAL_HTAB, segno);
+ Assert(entry != NULL);
+ entry->tmpseg_exists = false;
+ }
+}
+
+/*
+ * Create an astreamer that can read WAL from tar file.
*/
static astreamer *
astreamer_waldump_new(XLogDumpPrivate *privateInfo)
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index e2c96c3f4ca..96d17e99690 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -474,12 +474,51 @@ TarWALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
{
XLogDumpPrivate *private = state->private_data;
int count = required_read_len(private, targetPagePtr, reqLen);
+ XLogSegNo nextSegNo;
/* Bail out if the count to be read is not valid */
if (count < 0)
return -1;
- /* Read the WAL page from the archive streamer */
+ /*
+ * If the target page is in a different segment, first check for the WAL
+ * segment's physical existence in the temporary directory.
+ */
+ nextSegNo = state->seg.ws_segno;
+ if (!XLByteInSeg(targetPagePtr, nextSegNo, WalSegSz))
+ {
+ if (state->seg.ws_file >= 0)
+ {
+ close(state->seg.ws_file);
+ state->seg.ws_file = -1;
+
+ /* Remove this file, as it is no longer needed. */
+ remove_tmp_walseg(nextSegNo, true);
+ }
+
+ XLByteToSeg(targetPagePtr, nextSegNo, WalSegSz);
+ state->seg.ws_tli = private->timeline;
+ state->seg.ws_segno = nextSegNo;
+
+ /*
+ * If the next segment exists, open it and continue reading from there
+ */
+ if (tmp_walseg_exists(nextSegNo))
+ {
+ char *fpath;
+
+ fpath = get_tmp_walseg_path(nextSegNo);
+ state->seg.ws_file = open(fpath, O_RDONLY | PG_BINARY, 0);
+ pfree(fpath);
+ }
+ }
+
+ /* Continue reading from the open WAL segment, if any */
+ if (state->seg.ws_file >= 0)
+ return WALDumpReadPage(state, targetPagePtr, count, targetPtr,
+ readBuff);
+
+ /* Otherwise, read the WAL page from the archive streamer */
return read_archive_wal_page(private, targetPagePtr, count, readBuff);
}
diff --git a/src/bin/pg_waldump/pg_waldump.h b/src/bin/pg_waldump/pg_waldump.h
index ec7a33d40e0..03e02625ba1 100644
--- a/src/bin/pg_waldump/pg_waldump.h
+++ b/src/bin/pg_waldump/pg_waldump.h
@@ -58,4 +58,8 @@ extern int read_archive_wal_page(XLogDumpPrivate *privateInfo,
XLogRecPtr targetPagePtr,
Size count, char *readBuff);
+extern char *get_tmp_walseg_path(XLogSegNo segno);
+extern bool tmp_walseg_exists(XLogSegNo segno);
+extern void remove_tmp_walseg(XLogSegNo segno, bool update_entry);
+
#endif /* end of PG_WALDUMP_H */
diff --git a/src/bin/pg_waldump/t/001_basic.pl b/src/bin/pg_waldump/t/001_basic.pl
index 13567fbdba1..68b0cdd29e5 100644
--- a/src/bin/pg_waldump/t/001_basic.pl
+++ b/src/bin/pg_waldump/t/001_basic.pl
@@ -7,6 +7,7 @@ use Cwd;
use PostgreSQL::Test::Cluster;
use PostgreSQL::Test::Utils;
use Test::More;
+use List::Util qw(shuffle);
my $tar = $ENV{TAR};
@@ -272,7 +273,7 @@ sub generate_archive
}
closedir $dh;
- @files = sort @files;
+ @files = shuffle @files;
# move into the WAL directory before archiving files
my $cwd = getcwd;
--
2.47.1
[application/octet-stream] v10-0006-pg_verifybackup-Delay-default-WAL-directory-prep.patch (1.7K, 7-v10-0006-pg_verifybackup-Delay-default-WAL-directory-prep.patch)
download | inline diff:
From 4f62c2263fb567811dd11b275d883ea1e0b7a4db Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Wed, 16 Jul 2025 14:47:43 +0530
Subject: [PATCH v10 6/8] pg_verifybackup: Delay default WAL directory
preparation.
We are not sure whether to parse WAL from a directory or an archive
until the backup format is known. Therefore, we delay preparing the
default WAL directory until the point of parsing. This delay is
harmless, as the WAL directory is not used elsewhere.
---
src/bin/pg_verifybackup/pg_verifybackup.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/bin/pg_verifybackup/pg_verifybackup.c b/src/bin/pg_verifybackup/pg_verifybackup.c
index 456e0375e13..c6be75eba74 100644
--- a/src/bin/pg_verifybackup/pg_verifybackup.c
+++ b/src/bin/pg_verifybackup/pg_verifybackup.c
@@ -285,10 +285,6 @@ main(int argc, char **argv)
manifest_path = psprintf("%s/backup_manifest",
context.backup_directory);
- /* By default, look for the WAL in the backup directory, too. */
- if (wal_directory == NULL)
- wal_directory = psprintf("%s/pg_wal", context.backup_directory);
-
/*
* Try to read the manifest. We treat any errors encountered while parsing
* the manifest as fatal; there doesn't seem to be much point in trying to
@@ -368,6 +364,10 @@ main(int argc, char **argv)
if (context.format == 'p' && !context.skip_checksums)
verify_backup_checksums(&context);
+ /* By default, look for the WAL in the backup directory, too. */
+ if (wal_directory == NULL)
+ wal_directory = psprintf("%s/pg_wal", context.backup_directory);
+
/*
* Try to parse the required ranges of WAL records, unless we were told
* not to do so.
--
2.47.1
[application/octet-stream] v10-0007-pg_verifybackup-Rename-the-wal-directory-switch-.patch (5.9K, 8-v10-0007-pg_verifybackup-Rename-the-wal-directory-switch-.patch)
download | inline diff:
From d547aeb99303cc83cb1f8ad233804eb2e603d72e Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Tue, 25 Nov 2025 17:32:14 +0530
Subject: [PATCH v10 7/8] pg_verifybackup: Rename the wal-directory switch to
wal-path
With previous patches to pg_waldump can now decode WAL directly from
tar files. This means you'll be able to specify a tar archive path
instead of a traditional WAL directory.
To keep things consistent and more versatile, we should also
generalize the input switch for pg_verifybackup. It should accept
either a directory or a tar file path that contains WALs. This change
will also aligning it with the existing manifest-path switch naming.
== NOTE ==
The corresponding PO files require updating due to this change.
---
doc/src/sgml/ref/pg_verifybackup.sgml | 2 +-
src/bin/pg_verifybackup/pg_verifybackup.c | 22 +++++++++++-----------
src/bin/pg_verifybackup/t/007_wal.pl | 4 ++--
3 files changed, 14 insertions(+), 14 deletions(-)
diff --git a/doc/src/sgml/ref/pg_verifybackup.sgml b/doc/src/sgml/ref/pg_verifybackup.sgml
index 61c12975e4a..e9b8bfd51b1 100644
--- a/doc/src/sgml/ref/pg_verifybackup.sgml
+++ b/doc/src/sgml/ref/pg_verifybackup.sgml
@@ -261,7 +261,7 @@ PostgreSQL documentation
<varlistentry>
<term><option>-w <replaceable class="parameter">path</replaceable></option></term>
- <term><option>--wal-directory=<replaceable class="parameter">path</replaceable></option></term>
+ <term><option>--wal-path=<replaceable class="parameter">path</replaceable></option></term>
<listitem>
<para>
Try to parse WAL files stored in the specified directory, rather than
diff --git a/src/bin/pg_verifybackup/pg_verifybackup.c b/src/bin/pg_verifybackup/pg_verifybackup.c
index c6be75eba74..97178d585c3 100644
--- a/src/bin/pg_verifybackup/pg_verifybackup.c
+++ b/src/bin/pg_verifybackup/pg_verifybackup.c
@@ -93,7 +93,7 @@ static void verify_file_checksum(verifier_context *context,
uint8 *buffer);
static void parse_required_wal(verifier_context *context,
char *pg_waldump_path,
- char *wal_directory);
+ char *wal_path);
static astreamer *create_archive_verifier(verifier_context *context,
char *archive_name,
Oid tblspc_oid,
@@ -126,7 +126,7 @@ main(int argc, char **argv)
{"progress", no_argument, NULL, 'P'},
{"quiet", no_argument, NULL, 'q'},
{"skip-checksums", no_argument, NULL, 's'},
- {"wal-directory", required_argument, NULL, 'w'},
+ {"wal-path", required_argument, NULL, 'w'},
{NULL, 0, NULL, 0}
};
@@ -135,7 +135,7 @@ main(int argc, char **argv)
char *manifest_path = NULL;
bool no_parse_wal = false;
bool quiet = false;
- char *wal_directory = NULL;
+ char *wal_path = NULL;
char *pg_waldump_path = NULL;
DIR *dir;
@@ -221,8 +221,8 @@ main(int argc, char **argv)
context.skip_checksums = true;
break;
case 'w':
- wal_directory = pstrdup(optarg);
- canonicalize_path(wal_directory);
+ wal_path = pstrdup(optarg);
+ canonicalize_path(wal_path);
break;
default:
/* getopt_long already emitted a complaint */
@@ -365,15 +365,15 @@ main(int argc, char **argv)
verify_backup_checksums(&context);
/* By default, look for the WAL in the backup directory, too. */
- if (wal_directory == NULL)
- wal_directory = psprintf("%s/pg_wal", context.backup_directory);
+ if (wal_path == NULL)
+ wal_path = psprintf("%s/pg_wal", context.backup_directory);
/*
* Try to parse the required ranges of WAL records, unless we were told
* not to do so.
*/
if (!no_parse_wal)
- parse_required_wal(&context, pg_waldump_path, wal_directory);
+ parse_required_wal(&context, pg_waldump_path, wal_path);
/*
* If everything looks OK, tell the user this, unless we were asked to
@@ -1198,7 +1198,7 @@ verify_file_checksum(verifier_context *context, manifest_file *m,
*/
static void
parse_required_wal(verifier_context *context, char *pg_waldump_path,
- char *wal_directory)
+ char *wal_path)
{
manifest_data *manifest = context->manifest;
manifest_wal_range *this_wal_range = manifest->first_wal_range;
@@ -1208,7 +1208,7 @@ parse_required_wal(verifier_context *context, char *pg_waldump_path,
char *pg_waldump_cmd;
pg_waldump_cmd = psprintf("\"%s\" --quiet --path=\"%s\" --timeline=%u --start=%X/%08X --end=%X/%08X\n",
- pg_waldump_path, wal_directory, this_wal_range->tli,
+ pg_waldump_path, wal_path, this_wal_range->tli,
LSN_FORMAT_ARGS(this_wal_range->start_lsn),
LSN_FORMAT_ARGS(this_wal_range->end_lsn));
fflush(NULL);
@@ -1376,7 +1376,7 @@ usage(void)
printf(_(" -P, --progress show progress information\n"));
printf(_(" -q, --quiet do not print any output, except for errors\n"));
printf(_(" -s, --skip-checksums skip checksum verification\n"));
- printf(_(" -w, --wal-directory=PATH use specified path for WAL files\n"));
+ printf(_(" -w, --wal-path=PATH use specified path for WAL files\n"));
printf(_(" -V, --version output version information, then exit\n"));
printf(_(" -?, --help show this help, then exit\n"));
printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
diff --git a/src/bin/pg_verifybackup/t/007_wal.pl b/src/bin/pg_verifybackup/t/007_wal.pl
index 79087a1f6be..8ad2234453d 100644
--- a/src/bin/pg_verifybackup/t/007_wal.pl
+++ b/src/bin/pg_verifybackup/t/007_wal.pl
@@ -42,10 +42,10 @@ command_ok([ 'pg_verifybackup', '--no-parse-wal', $backup_path ],
command_ok(
[
'pg_verifybackup',
- '--wal-directory' => $relocated_pg_wal,
+ '--wal-path' => $relocated_pg_wal,
$backup_path
],
- '--wal-directory can be used to specify WAL directory');
+ '--wal-path can be used to specify WAL directory');
# Move directory back to original location.
rename($relocated_pg_wal, $original_pg_wal) || die "rename pg_wal back: $!";
--
2.47.1
[application/octet-stream] v10-0008-pg_verifybackup-enabled-WAL-parsing-for-tar-form.patch (9.9K, 9-v10-0008-pg_verifybackup-enabled-WAL-parsing-for-tar-form.patch)
download | inline diff:
From 31791ed0320af216c80a8a72017670f0b0e06752 Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Tue, 25 Nov 2025 17:34:26 +0530
Subject: [PATCH v10 8/8] pg_verifybackup: enabled WAL parsing for tar-format
backup
Now that pg_waldump supports decoding from tar archives, we should
leverage this functionality to remove the previous restriction on WAL
parsing for tar-backed formats.
---
doc/src/sgml/ref/pg_verifybackup.sgml | 5 +-
src/bin/pg_verifybackup/pg_verifybackup.c | 66 +++++++++++++------
src/bin/pg_verifybackup/t/002_algorithm.pl | 4 --
src/bin/pg_verifybackup/t/003_corruption.pl | 4 +-
src/bin/pg_verifybackup/t/008_untar.pl | 5 +-
src/bin/pg_verifybackup/t/010_client_untar.pl | 5 +-
6 files changed, 50 insertions(+), 39 deletions(-)
diff --git a/doc/src/sgml/ref/pg_verifybackup.sgml b/doc/src/sgml/ref/pg_verifybackup.sgml
index e9b8bfd51b1..16b50b5a4df 100644
--- a/doc/src/sgml/ref/pg_verifybackup.sgml
+++ b/doc/src/sgml/ref/pg_verifybackup.sgml
@@ -36,10 +36,7 @@ PostgreSQL documentation
<literal>backup_manifest</literal> generated by the server at the time
of the backup. The backup may be stored either in the "plain" or the "tar"
format; this includes tar-format backups compressed with any algorithm
- supported by <application>pg_basebackup</application>. However, at present,
- <literal>WAL</literal> verification is supported only for plain-format
- backups. Therefore, if the backup is stored in tar-format, the
- <literal>-n, --no-parse-wal</literal> option should be used.
+ supported by <application>pg_basebackup</application>.
</para>
<para>
diff --git a/src/bin/pg_verifybackup/pg_verifybackup.c b/src/bin/pg_verifybackup/pg_verifybackup.c
index 97178d585c3..baa5f9dfa5e 100644
--- a/src/bin/pg_verifybackup/pg_verifybackup.c
+++ b/src/bin/pg_verifybackup/pg_verifybackup.c
@@ -74,7 +74,9 @@ pg_noreturn static void report_manifest_error(JsonManifestParseContext *context,
const char *fmt,...)
pg_attribute_printf(2, 3);
-static void verify_tar_backup(verifier_context *context, DIR *dir);
+static void verify_tar_backup(verifier_context *context, DIR *dir,
+ char **base_archive_path,
+ char **wal_archive_path);
static void verify_plain_backup_directory(verifier_context *context,
char *relpath, char *fullpath,
DIR *dir);
@@ -83,7 +85,9 @@ static void verify_plain_backup_file(verifier_context *context, char *relpath,
static void verify_control_file(const char *controlpath,
uint64 manifest_system_identifier);
static void precheck_tar_backup_file(verifier_context *context, char *relpath,
- char *fullpath, SimplePtrList *tarfiles);
+ char *fullpath, SimplePtrList *tarfiles,
+ char **base_archive_path,
+ char **wal_archive_path);
static void verify_tar_file(verifier_context *context, char *relpath,
char *fullpath, astreamer *streamer);
static void report_extra_backup_files(verifier_context *context);
@@ -136,6 +140,8 @@ main(int argc, char **argv)
bool no_parse_wal = false;
bool quiet = false;
char *wal_path = NULL;
+ char *base_archive_path = NULL;
+ char *wal_archive_path = NULL;
char *pg_waldump_path = NULL;
DIR *dir;
@@ -327,17 +333,6 @@ main(int argc, char **argv)
pfree(path);
}
- /*
- * XXX: In the future, we should consider enhancing pg_waldump to read WAL
- * files from an archive.
- */
- if (!no_parse_wal && context.format == 't')
- {
- pg_log_error("pg_waldump cannot read tar files");
- pg_log_error_hint("You must use -n/--no-parse-wal when verifying a tar-format backup.");
- exit(1);
- }
-
/*
* Perform the appropriate type of verification appropriate based on the
* backup format. This will close 'dir'.
@@ -346,7 +341,7 @@ main(int argc, char **argv)
verify_plain_backup_directory(&context, NULL, context.backup_directory,
dir);
else
- verify_tar_backup(&context, dir);
+ verify_tar_backup(&context, dir, &base_archive_path, &wal_archive_path);
/*
* The "matched" flag should now be set on every entry in the hash table.
@@ -364,9 +359,28 @@ main(int argc, char **argv)
if (context.format == 'p' && !context.skip_checksums)
verify_backup_checksums(&context);
- /* By default, look for the WAL in the backup directory, too. */
+ /*
+ * By default, WAL files are expected to be found in the backup directory
+ * for plain-format backups. In the case of tar-format backups, if a
+ * separate WAL archive is not found, the WAL files are most likely
+ * included within the main data directory archive.
+ */
if (wal_path == NULL)
- wal_path = psprintf("%s/pg_wal", context.backup_directory);
+ {
+ if (context.format == 'p')
+ wal_path = psprintf("%s/pg_wal", context.backup_directory);
+ else if (wal_archive_path)
+ wal_path = wal_archive_path;
+ else if (base_archive_path)
+ wal_path = base_archive_path;
+ else
+ {
+ pg_log_error("WAL archive not found");
+ pg_log_error_hint("Specify the correct path using the option -w/--wal-path. "
+ "Or you must use -n/--no-parse-wal when verifying a tar-format backup.");
+ exit(1);
+ }
+ }
/*
* Try to parse the required ranges of WAL records, unless we were told
@@ -787,7 +801,8 @@ verify_control_file(const char *controlpath, uint64 manifest_system_identifier)
* close when we're done with it.
*/
static void
-verify_tar_backup(verifier_context *context, DIR *dir)
+verify_tar_backup(verifier_context *context, DIR *dir, char **base_archive_path,
+ char **wal_archive_path)
{
struct dirent *dirent;
SimplePtrList tarfiles = {NULL, NULL};
@@ -816,7 +831,8 @@ verify_tar_backup(verifier_context *context, DIR *dir)
char *fullpath;
fullpath = psprintf("%s/%s", context->backup_directory, filename);
- precheck_tar_backup_file(context, filename, fullpath, &tarfiles);
+ precheck_tar_backup_file(context, filename, fullpath, &tarfiles,
+ base_archive_path, wal_archive_path);
pfree(fullpath);
}
}
@@ -875,11 +891,13 @@ verify_tar_backup(verifier_context *context, DIR *dir)
*
* The arguments to this function are mostly the same as the
* verify_plain_backup_file. The additional argument outputs a list of valid
- * tar files.
+ * tar files, along with the full paths to the main archive and the WAL
+ * directory archive.
*/
static void
precheck_tar_backup_file(verifier_context *context, char *relpath,
- char *fullpath, SimplePtrList *tarfiles)
+ char *fullpath, SimplePtrList *tarfiles,
+ char **base_archive_path, char **wal_archive_path)
{
struct stat sb;
Oid tblspc_oid = InvalidOid;
@@ -918,9 +936,17 @@ precheck_tar_backup_file(verifier_context *context, char *relpath,
* extension such as .gz, .lz4, or .zst.
*/
if (strncmp("base", relpath, 4) == 0)
+ {
suffix = relpath + 4;
+
+ *base_archive_path = pstrdup(fullpath);
+ }
else if (strncmp("pg_wal", relpath, 6) == 0)
+ {
suffix = relpath + 6;
+
+ *wal_archive_path = pstrdup(fullpath);
+ }
else
{
/* Expected a <tablespaceoid>.tar file here. */
diff --git a/src/bin/pg_verifybackup/t/002_algorithm.pl b/src/bin/pg_verifybackup/t/002_algorithm.pl
index 0556191ec9d..edc515d5904 100644
--- a/src/bin/pg_verifybackup/t/002_algorithm.pl
+++ b/src/bin/pg_verifybackup/t/002_algorithm.pl
@@ -30,10 +30,6 @@ sub test_checksums
{
# Add switch to get a tar-format backup
push @backup, ('--format' => 'tar');
-
- # Add switch to skip WAL verification, which is not yet supported for
- # tar-format backups
- push @verify, ('--no-parse-wal');
}
# A backup with a bogus algorithm should fail.
diff --git a/src/bin/pg_verifybackup/t/003_corruption.pl b/src/bin/pg_verifybackup/t/003_corruption.pl
index b1d65b8aa0f..882d75d9dc2 100644
--- a/src/bin/pg_verifybackup/t/003_corruption.pl
+++ b/src/bin/pg_verifybackup/t/003_corruption.pl
@@ -193,10 +193,8 @@ for my $scenario (@scenario)
command_ok([ $tar, '-cf' => "$tar_backup_path/base.tar", '.' ]);
chdir($cwd) || die "chdir: $!";
- # Now check that the backup no longer verifies. We must use -n
- # here, because pg_waldump can't yet read WAL from a tarfile.
command_fails_like(
- [ 'pg_verifybackup', '--no-parse-wal', $tar_backup_path ],
+ [ 'pg_verifybackup', $tar_backup_path ],
$scenario->{'fails_like'},
"corrupt backup fails verification: $name");
diff --git a/src/bin/pg_verifybackup/t/008_untar.pl b/src/bin/pg_verifybackup/t/008_untar.pl
index ae67ae85a31..161c08c190d 100644
--- a/src/bin/pg_verifybackup/t/008_untar.pl
+++ b/src/bin/pg_verifybackup/t/008_untar.pl
@@ -47,7 +47,6 @@ my $tsoid = $primary->safe_psql(
SELECT oid FROM pg_tablespace WHERE spcname = 'regress_ts1'));
my $backup_path = $primary->backup_dir . '/server-backup';
-my $extract_path = $primary->backup_dir . '/extracted-backup';
my @test_configuration = (
{
@@ -123,14 +122,12 @@ for my $tc (@test_configuration)
# Verify tar backup.
$primary->command_ok(
[
- 'pg_verifybackup', '--no-parse-wal',
- '--exit-on-error', $backup_path,
+ 'pg_verifybackup', '--exit-on-error', $backup_path,
],
"verify backup, compression $method");
# Cleanup.
rmtree($backup_path);
- rmtree($extract_path);
}
}
diff --git a/src/bin/pg_verifybackup/t/010_client_untar.pl b/src/bin/pg_verifybackup/t/010_client_untar.pl
index 1ac7b5db75a..9670fbe4fda 100644
--- a/src/bin/pg_verifybackup/t/010_client_untar.pl
+++ b/src/bin/pg_verifybackup/t/010_client_untar.pl
@@ -32,7 +32,6 @@ print $jf $junk_data;
close $jf;
my $backup_path = $primary->backup_dir . '/client-backup';
-my $extract_path = $primary->backup_dir . '/extracted-backup';
my @test_configuration = (
{
@@ -137,13 +136,11 @@ for my $tc (@test_configuration)
# Verify tar backup.
$primary->command_ok(
[
- 'pg_verifybackup', '--no-parse-wal',
- '--exit-on-error', $backup_path,
+ 'pg_verifybackup', '--exit-on-error', $backup_path,
],
"verify backup, compression $method");
# Cleanup.
- rmtree($extract_path);
rmtree($backup_path);
}
}
--
2.47.1
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Subject: Re: pg_waldump: support decoding of WAL inside tarfile
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