On Tue, Sep 20, 2022 at 7:20 AM Michael Paquier <mich...@paquier.xyz> wrote:
>
> The main regression test suite should not include direct calls to
> pg_backup_start() or pg_backup_stop() as these depend on wal_level,
> and we spend a certain amount of resources in keeping the tests a
> maximum portable across such configurations, wal_level = minimal being
> one of them. One portable example is in 001_stream_rep.pl.
Understood.
> > That's a good idea. I'm marking a flag if the label name overflows (>
> > MAXPGPATH), later using it in do_pg_backup_start() to error out. We
> > could've thrown error directly, but that changes the behaviour - right
> > now, first "
> > wal_level must be set to \"replica\" or \"logical\" at server start."
> > gets emitted and then label name overflow error - I don't want to do
> > that.
>
> - if (strlen(backupidstr) > MAXPGPATH)
> + if (state->name_overflowed == true)
> ereport(ERROR,
> (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
> errmsg("backup label too long (max %d bytes)",
> It does not strike me as a huge issue to force a truncation of such
> backup label names. 1024 is large enough for basically all users,
> in my opinion. Or you could just truncate in the internal logic, but
> still complain at MAXPGPATH - 1 as the last byte would be for the zero
> termination. In short, there is no need to complicate things with
> name_overflowed.
We currently allow MAXPGPATH bytes of label name excluding null
termination. I don't want to change this behaviour. In the attached v9
patch, I'm truncating the larger names to MAXPGPATH + 1 bytes in
backup state (one extra byte for representing that the name has
overflown, and another extra byte for null termination).
> + StringInfo backup_label; /* backup_label file contents */
> + StringInfo tablespace_map; /* tablespace_map file contents */
> + StringInfo history_file; /* history file contents */
> IMV, repeating a point I already made once upthread, BackupState
> should hold none of these. Let's just generate the contents of these
> files in the contexts where they are needed, making BackupState
> something to rely on to build them in the code paths where they are
> necessary. This is going to make the reasoning around the memory
> contexts where each one of them is stored much easier and reduce the
> changes of bugs in the long-term.
I've separated out these variables from the backup state, please see
the attached v9 patch.
> > I've also taken help of the error callback mechanism to clean up the
> > allocated memory in case of a failure. For do_pg_abort_backup() cases,
> > I think we don't need to clean the memory because that gets called on
> > proc exit (before_shmem_exit()).
>
> Memory could still bloat while the process running the SQL functions
> is running depending on the error code path, anyway.
I didn't get your point. Can you please elaborate it? I think adding
error callbacks at the right places would free up the memory for us.
Please note that we already are causing memory leaks on HEAD today.
I addressed the above review comments. I also changed a wrong comment
[1] that lies before pg_backup_start() even after the removal of
exclusive backup.
I'm attaching v9 patch set herewith, 0001 - refactors the backup code
with backup state, 0002 - adds error callbacks to clean up the memory
allocated for backup variables. Please review them further.
[1]
* Essentially what this does is to create a backup label file in $PGDATA,
* where it will be archived as part of the backup dump. The label file
* contains the user-supplied label string (typically this would be used
* to tell where the backup dump will be stored) and the starting time and
* starting WAL location for the dump.
--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
From ab1e86ac7fb75a2d2219c7681ead40faf8c01446 Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Date: Tue, 20 Sep 2022 10:04:29 +0000
Subject: [PATCH v9] Refactor backup related code
Refactor backup related code, advantages of doing so are following:
1) backup state is more structured now - all in a single structure,
callers can create backup_label contents whenever required, either
during the pg_backup_start or the pg_backup_stop or in between.
2) no parsing of backup_label file lines now, no error checking
for invalid parsing.
3) backup_label and history file contents have most of the things
in common, they can now be created within a single function.
4) makes backup related code extensible and readable.
This introduces new source files xlogbackup.c/.h for backup related
code and adds the new code in there. The xlog.c file has already grown
to ~9000 LOC (as of this time). Eventually, we would want to move
all the backup related code from xlog.c, xlogfuncs.c, elsewhere to
here.
Author: Bharath Rupireddy
Reviewed-by: Michael Paquier
Reviewed-by: Fujii Masao
Discussion: https://www.postgresql.org/message-id/CALj2ACVqNUEXkaMKyHHOdvScfN9E4LuCWsX_R-YRNfzQ727CdA%40mail.gmail.com
---
src/backend/access/transam/Makefile | 1 +
src/backend/access/transam/xlog.c | 247 +++++++++---------------
src/backend/access/transam/xlogbackup.c | 151 +++++++++++++++
src/backend/access/transam/xlogfuncs.c | 90 +++++----
src/backend/backup/basebackup.c | 41 ++--
src/include/access/xlog.h | 9 +-
src/include/access/xlogbackup.h | 53 +++++
7 files changed, 384 insertions(+), 208 deletions(-)
create mode 100644 src/backend/access/transam/xlogbackup.c
create mode 100644 src/include/access/xlogbackup.h
diff --git a/src/backend/access/transam/Makefile b/src/backend/access/transam/Makefile
index 3e5444a6f7..661c55a9db 100644
--- a/src/backend/access/transam/Makefile
+++ b/src/backend/access/transam/Makefile
@@ -29,6 +29,7 @@ OBJS = \
xact.o \
xlog.o \
xlogarchive.o \
+ xlogbackup.o \
xlogfuncs.o \
xloginsert.o \
xlogprefetcher.o \
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index eb0430fe98..d25750e783 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -8236,46 +8236,40 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
/*
* do_pg_backup_start is the workhorse of the user-visible pg_backup_start()
* function. It creates the necessary starting checkpoint and constructs the
- * backup label and tablespace map.
- *
- * Input parameters are "backupidstr" (the backup label string) and "fast"
- * (if true, we do the checkpoint in immediate mode to make it faster).
- *
- * The backup label and tablespace map contents are appended to *labelfile and
- * *tblspcmapfile, and the caller is responsible for including them in the
- * backup archive as 'backup_label' and 'tablespace_map'.
- * tblspcmapfile is required mainly for tar format in windows as native windows
- * utilities are not able to create symlinks while extracting files from tar.
- * However for consistency and platform-independence, we do it the same way
- * everywhere.
- *
- * If "tablespaces" isn't NULL, it receives a list of tablespaceinfo structs
- * describing the cluster's tablespaces.
- *
- * Returns the minimum WAL location that must be present to restore from this
- * backup, and the corresponding timeline ID in *starttli_p.
+ * backup state.
+ *
+ * Input parameters are "state" (containing backup state), "fast" (if true,
+ * we do the checkpoint in immediate mode to make it faster), and "tablespaces"
+ * (if non-NULL, indicates a list of tablespaceinfo structs describing the
+ * cluster's tablespaces.).
+ *
+ * The tablespace map contents are appended to passed-in parameter
+ * tablespace_map and the caller is responsible for including it in the backup
+ * archive as 'tablespace_map'. The tablespace_map file is required mainly for
+ * tar format in windows as native windows utilities are not able to create
+ * symlinks while extracting files from tar. However for consistency and
+ * platform-independence, we do it the same way everywhere.
+ *
+ * It fills in backup state with information such as the minimum WAL location
+ * that must be present to restore from this backup (starttli), and the
+ * corresponding timeline ID (starttli), last checkpoint location
+ * (checkpointloc), start time of the backup (starttime), whether the backup started
+ * in recovery (started_in_recovery) and so on.
*
* Every successfully started backup must be stopped by calling
- * do_pg_backup_stop() or do_pg_abort_backup(). There can be many
- * backups active at the same time.
+ * do_pg_backup_stop() or do_pg_abort_backup(). There can be many backups
+ * active at the same time.
*
* It is the responsibility of the caller of this function to verify the
* permissions of the calling user!
*/
-XLogRecPtr
-do_pg_backup_start(const char *backupidstr, bool fast, TimeLineID *starttli_p,
- StringInfo labelfile, List **tablespaces,
- StringInfo tblspcmapfile)
+void
+do_pg_backup_start(BackupState *state, bool fast, List **tablespaces,
+ StringInfo tablespace_map)
{
bool backup_started_in_recovery = false;
- XLogRecPtr checkpointloc;
- XLogRecPtr startpoint;
- TimeLineID starttli;
- pg_time_t stamp_time;
- char strfbuf[128];
- char xlogfilename[MAXFNAMELEN];
- XLogSegNo _logSegNo;
+ Assert(state != NULL);
backup_started_in_recovery = RecoveryInProgress();
/*
@@ -8288,7 +8282,7 @@ do_pg_backup_start(const char *backupidstr, bool fast, TimeLineID *starttli_p,
errmsg("WAL level not sufficient for making an online backup"),
errhint("wal_level must be set to \"replica\" or \"logical\" at server start.")));
- if (strlen(backupidstr) > MAXPGPATH)
+ if (strlen(state->name) > MAXPGPATH)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("backup label too long (max %d bytes)",
@@ -8385,9 +8379,9 @@ do_pg_backup_start(const char *backupidstr, bool fast, TimeLineID *starttli_p,
* pointer.
*/
LWLockAcquire(ControlFileLock, LW_SHARED);
- checkpointloc = ControlFile->checkPoint;
- startpoint = ControlFile->checkPointCopy.redo;
- starttli = ControlFile->checkPointCopy.ThisTimeLineID;
+ state->checkpointloc = ControlFile->checkPoint;
+ state->startpoint = ControlFile->checkPointCopy.redo;
+ state->starttli = ControlFile->checkPointCopy.ThisTimeLineID;
checkpointfpw = ControlFile->checkPointCopy.fullPageWrites;
LWLockRelease(ControlFileLock);
@@ -8404,7 +8398,7 @@ do_pg_backup_start(const char *backupidstr, bool fast, TimeLineID *starttli_p,
recptr = XLogCtl->lastFpwDisableRecPtr;
SpinLockRelease(&XLogCtl->info_lck);
- if (!checkpointfpw || startpoint <= recptr)
+ if (!checkpointfpw || state->startpoint <= recptr)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("WAL generated with full_page_writes=off was replayed "
@@ -8436,19 +8430,16 @@ do_pg_backup_start(const char *backupidstr, bool fast, TimeLineID *starttli_p,
* either because only few buffers have been dirtied yet.
*/
WALInsertLockAcquireExclusive();
- if (XLogCtl->Insert.lastBackupStart < startpoint)
+ if (XLogCtl->Insert.lastBackupStart < state->startpoint)
{
- XLogCtl->Insert.lastBackupStart = startpoint;
+ XLogCtl->Insert.lastBackupStart = state->startpoint;
gotUniqueStartpoint = true;
}
WALInsertLockRelease();
} while (!gotUniqueStartpoint);
- XLByteToSeg(startpoint, _logSegNo, wal_segment_size);
- XLogFileName(xlogfilename, starttli, _logSegNo, wal_segment_size);
-
/*
- * Construct tablespace_map file.
+ * Construct tablespace_map contents.
*/
datadirpathlen = strlen(DataDir);
@@ -8525,46 +8516,23 @@ do_pg_backup_start(const char *backupidstr, bool fast, TimeLineID *starttli_p,
if (tablespaces)
*tablespaces = lappend(*tablespaces, ti);
- appendStringInfo(tblspcmapfile, "%s %s\n",
+ appendStringInfo(tablespace_map, "%s %s\n",
ti->oid, escapedpath.data);
pfree(escapedpath.data);
}
FreeDir(tblspcdir);
- /*
- * Construct backup label file.
- */
-
- /* Use the log timezone here, not the session timezone */
- stamp_time = (pg_time_t) time(NULL);
- pg_strftime(strfbuf, sizeof(strfbuf),
- "%Y-%m-%d %H:%M:%S %Z",
- pg_localtime(&stamp_time, log_timezone));
- appendStringInfo(labelfile, "START WAL LOCATION: %X/%X (file %s)\n",
- LSN_FORMAT_ARGS(startpoint), xlogfilename);
- appendStringInfo(labelfile, "CHECKPOINT LOCATION: %X/%X\n",
- LSN_FORMAT_ARGS(checkpointloc));
- appendStringInfo(labelfile, "BACKUP METHOD: streamed\n");
- appendStringInfo(labelfile, "BACKUP FROM: %s\n",
- backup_started_in_recovery ? "standby" : "primary");
- appendStringInfo(labelfile, "START TIME: %s\n", strfbuf);
- appendStringInfo(labelfile, "LABEL: %s\n", backupidstr);
- appendStringInfo(labelfile, "START TIMELINE: %u\n", starttli);
+ state->starttime = (pg_time_t) time(NULL);
}
PG_END_ENSURE_ERROR_CLEANUP(pg_backup_start_callback, (Datum) 0);
+ state->started_in_recovery = backup_started_in_recovery;
+
/*
* Mark that the start phase has correctly finished for the backup.
*/
sessionBackupState = SESSION_BACKUP_RUNNING;
-
- /*
- * We're done. As a convenience, return the starting WAL location.
- */
- if (starttli_p)
- *starttli_p = starttli;
- return startpoint;
}
/* Error cleanup callback for pg_backup_start */
@@ -8596,48 +8564,43 @@ get_backup_status(void)
/*
* do_pg_backup_stop
*
- * Utility function called at the end of an online backup. It cleans up the
- * backup state and can optionally wait for WAL segments to be archived.
+ * Utility function called at the end of an online backup. It creates history
+ * file (if required), resets sessionBackupState and so on. It can optionally
+ * wait for WAL segments to be archived.
*
- * Returns the last WAL location that must be present to restore from this
- * backup, and the corresponding timeline ID in *stoptli_p.
+ * It fills in backup state with information such as the last WAL location that
+ * must be present to restore from this backup (stoppoint), and the
+ * corresponding timeline ID (stoptli), stop time of the backup (stoptime) and
+ * so on.
*
* It is the responsibility of the caller of this function to verify the
* permissions of the calling user!
+ *
+ * It is the responsibility of the caller to create backup label contents by
+ * calling build_backup_content() with appropriate parameters.
*/
-XLogRecPtr
-do_pg_backup_stop(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p)
+void
+do_pg_backup_stop(BackupState *state, bool waitforarchive)
{
- bool backup_started_in_recovery = false;
- XLogRecPtr startpoint;
- XLogRecPtr stoppoint;
- TimeLineID stoptli;
- pg_time_t stamp_time;
- char strfbuf[128];
+ bool backup_stopped_in_recovery = false;
char histfilepath[MAXPGPATH];
- char startxlogfilename[MAXFNAMELEN];
- char stopxlogfilename[MAXFNAMELEN];
char lastxlogfilename[MAXFNAMELEN];
char histfilename[MAXFNAMELEN];
- char backupfrom[20];
XLogSegNo _logSegNo;
FILE *fp;
- char ch;
int seconds_before_warning;
int waits = 0;
bool reported_waiting = false;
- char *remaining;
- char *ptr;
- uint32 hi,
- lo;
- backup_started_in_recovery = RecoveryInProgress();
+ Assert(state != NULL);
+
+ backup_stopped_in_recovery = RecoveryInProgress();
/*
* During recovery, we don't need to check WAL level. Because, if WAL
* level is not sufficient, it's impossible to get here during recovery.
*/
- if (!backup_started_in_recovery && !XLogIsNeeded())
+ if (!backup_stopped_in_recovery && !XLogIsNeeded())
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("WAL level not sufficient for making an online backup"),
@@ -8678,29 +8641,11 @@ do_pg_backup_stop(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p)
WALInsertLockRelease();
/*
- * Read and parse the START WAL LOCATION line (this code is pretty crude,
- * but we are not expecting any variability in the file format).
- */
- if (sscanf(labelfile, "START WAL LOCATION: %X/%X (file %24s)%c",
- &hi, &lo, startxlogfilename,
- &ch) != 4 || ch != '\n')
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("invalid data in file \"%s\"", BACKUP_LABEL_FILE)));
- startpoint = ((uint64) hi) << 32 | lo;
- remaining = strchr(labelfile, '\n') + 1; /* %n is not portable enough */
-
- /*
- * Parse the BACKUP FROM line. If we are taking an online backup from the
- * standby, we confirm that the standby has not been promoted during the
- * backup.
+ * If we are taking an online backup from the standby, we confirm that the
+ * standby has not been promoted during the backup.
*/
- ptr = strstr(remaining, "BACKUP FROM:");
- if (!ptr || sscanf(ptr, "BACKUP FROM: %19s\n", backupfrom) != 1)
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("invalid data in file \"%s\"", BACKUP_LABEL_FILE)));
- if (strcmp(backupfrom, "standby") == 0 && !backup_started_in_recovery)
+ if (state->started_in_recovery == true &&
+ backup_stopped_in_recovery == false)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("the standby was promoted during online backup"),
@@ -8736,7 +8681,7 @@ do_pg_backup_stop(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p)
* an archiver is not invoked. So it doesn't seem worthwhile to write a
* backup history file during recovery.
*/
- if (backup_started_in_recovery)
+ if (backup_stopped_in_recovery)
{
XLogRecPtr recptr;
@@ -8748,7 +8693,7 @@ do_pg_backup_stop(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p)
recptr = XLogCtl->lastFpwDisableRecPtr;
SpinLockRelease(&XLogCtl->info_lck);
- if (startpoint <= recptr)
+ if (state->startpoint <= recptr)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("WAL generated with full_page_writes=off was replayed "
@@ -8760,24 +8705,27 @@ do_pg_backup_stop(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p)
LWLockAcquire(ControlFileLock, LW_SHARED);
- stoppoint = ControlFile->minRecoveryPoint;
- stoptli = ControlFile->minRecoveryPointTLI;
+ state->stoppoint = ControlFile->minRecoveryPoint;
+ state->stoptli = ControlFile->minRecoveryPointTLI;
LWLockRelease(ControlFileLock);
}
else
{
+ StringInfo history_file;
+
/*
* Write the backup-end xlog record
*/
XLogBeginInsert();
- XLogRegisterData((char *) (&startpoint), sizeof(startpoint));
- stoppoint = XLogInsert(RM_XLOG_ID, XLOG_BACKUP_END);
+ XLogRegisterData((char *) (&state->startpoint),
+ sizeof(state->startpoint));
+ state->stoppoint = XLogInsert(RM_XLOG_ID, XLOG_BACKUP_END);
/*
* Given that we're not in recovery, InsertTimeLineID is set and can't
* change, so we can read it without a lock.
*/
- stoptli = XLogCtl->InsertTimeLineID;
+ state->stoptli = XLogCtl->InsertTimeLineID;
/*
* Force a switch to a new xlog segment file, so that the backup is
@@ -8785,45 +8733,36 @@ do_pg_backup_stop(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p)
*/
RequestXLogSwitch(false);
- XLByteToPrevSeg(stoppoint, _logSegNo, wal_segment_size);
- XLogFileName(stopxlogfilename, stoptli, _logSegNo, wal_segment_size);
-
- /* Use the log timezone here, not the session timezone */
- stamp_time = (pg_time_t) time(NULL);
- pg_strftime(strfbuf, sizeof(strfbuf),
- "%Y-%m-%d %H:%M:%S %Z",
- pg_localtime(&stamp_time, log_timezone));
+ XLByteToPrevSeg(state->stoppoint, _logSegNo, wal_segment_size);
+ state->stoptime = (pg_time_t) time(NULL);
/*
- * Write the backup history file
+ * Write the backup history file. Add backup_label file contents too it.
*/
- XLByteToSeg(startpoint, _logSegNo, wal_segment_size);
- BackupHistoryFilePath(histfilepath, stoptli, _logSegNo,
- startpoint, wal_segment_size);
+ XLByteToSeg(state->startpoint, _logSegNo, wal_segment_size);
+ BackupHistoryFilePath(histfilepath, state->stoptli, _logSegNo,
+ state->startpoint, wal_segment_size);
fp = AllocateFile(histfilepath, "w");
if (!fp)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not create file \"%s\": %m",
histfilepath)));
- fprintf(fp, "START WAL LOCATION: %X/%X (file %s)\n",
- LSN_FORMAT_ARGS(startpoint), startxlogfilename);
- fprintf(fp, "STOP WAL LOCATION: %X/%X (file %s)\n",
- LSN_FORMAT_ARGS(stoppoint), stopxlogfilename);
- /*
- * Transfer remaining lines including label and start timeline to
- * history file.
- */
- fprintf(fp, "%s", remaining);
- fprintf(fp, "STOP TIME: %s\n", strfbuf);
- fprintf(fp, "STOP TIMELINE: %u\n", stoptli);
+ /* Construct history file contents. */
+ history_file = makeStringInfo();
+ build_backup_content(state, true, history_file);
+
+ fprintf(fp, "%s", history_file->data);
+
if (fflush(fp) || ferror(fp) || FreeFile(fp))
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not write file \"%s\": %m",
histfilepath)));
+ pfree(history_file->data);
+
/*
* Clean out any no-longer-needed history files. As a side effect,
* this will post a .ready file for the newly created history file,
@@ -8855,15 +8794,16 @@ do_pg_backup_stop(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p)
*/
if (waitforarchive &&
- ((!backup_started_in_recovery && XLogArchivingActive()) ||
- (backup_started_in_recovery && XLogArchivingAlways())))
+ ((!backup_stopped_in_recovery && XLogArchivingActive()) ||
+ (backup_stopped_in_recovery && XLogArchivingAlways())))
{
- XLByteToPrevSeg(stoppoint, _logSegNo, wal_segment_size);
- XLogFileName(lastxlogfilename, stoptli, _logSegNo, wal_segment_size);
+ XLByteToPrevSeg(state->stoppoint, _logSegNo, wal_segment_size);
+ XLogFileName(lastxlogfilename, state->stoptli, _logSegNo,
+ wal_segment_size);
- XLByteToSeg(startpoint, _logSegNo, wal_segment_size);
- BackupHistoryFileName(histfilename, stoptli, _logSegNo,
- startpoint, wal_segment_size);
+ XLByteToSeg(state->startpoint, _logSegNo, wal_segment_size);
+ BackupHistoryFileName(histfilename, state->stoptli, _logSegNo,
+ state->startpoint, wal_segment_size);
seconds_before_warning = 60;
waits = 0;
@@ -8904,13 +8844,6 @@ do_pg_backup_stop(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p)
else if (waitforarchive)
ereport(NOTICE,
(errmsg("WAL archiving is not enabled; you must ensure that all required WAL segments are copied through other means to complete the backup")));
-
- /*
- * We're done. As a convenience, return the ending WAL location.
- */
- if (stoptli_p)
- *stoptli_p = stoptli;
- return stoppoint;
}
diff --git a/src/backend/access/transam/xlogbackup.c b/src/backend/access/transam/xlogbackup.c
new file mode 100644
index 0000000000..38c37cc7db
--- /dev/null
+++ b/src/backend/access/transam/xlogbackup.c
@@ -0,0 +1,151 @@
+/*-------------------------------------------------------------------------
+ * xlogbackup.c
+ *
+ * This file contains backup related code.
+ *
+ * Copyright (c) 2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/backend/access/transam/xlogbackup.c
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/xlog.h"
+#include "access/xlog_internal.h"
+#include <access/xlogbackup.h>
+#include "utils/memutils.h"
+
+static void fill_backup_label_name(BackupState *state, const char* name);
+
+/*
+ * Allocate backup state and fill in the passed-in label name.
+ *
+ * Note that the caller has to ensure right memory context is set for the
+ * backup state.
+ */
+BackupState *
+allocate_backup_state(const char *name)
+{
+ BackupState *state;
+
+ state = (BackupState *) palloc0(sizeof(BackupState));
+
+ fill_backup_label_name(state, name);
+
+ return state;
+}
+
+/*
+ * Reset backup state and its members and fill in the passed-in label name.
+ */
+void
+reset_backup_state(BackupState *state, const char *name)
+{
+ if (state == NULL)
+ return; /* nothing to do */
+
+ MemSet(state, 0, sizeof(BackupState));
+ MemSet(state->name, '\0', sizeof(state->name));
+
+ fill_backup_label_name(state, name);
+}
+
+/*
+ * Thin helper function to fill label name (after truncating it, if necessary)
+ * in backup state.
+ */
+static void
+fill_backup_label_name(BackupState *state, const char* name)
+{
+ Size length;
+
+ length = strlen(name);
+
+ /*
+ * Truncate the backup label name whose length is greater than MAXPGPATH
+ * bytes as we will anyways error out later in do_pg_backup_start(). We
+ * truncate it to be one byte more to figure out the name has actually
+ * overflown.
+ */
+ if (length > MAXPGPATH)
+ length = MAXPGPATH + 1;
+
+ memcpy(state->name, name, length);
+}
+
+/*
+ * Deallocate backup state, backup_label and tablespace_map variables.
+ */
+void
+deallocate_backup_variables(BackupState *state, StringInfo backup_label,
+ StringInfo tablespace_map)
+{
+ if (state != NULL)
+ pfree(state);
+
+ if (backup_label != NULL)
+ pfree(backup_label->data);
+
+ if (tablespace_map != NULL)
+ pfree(tablespace_map->data);
+}
+
+/*
+ * Construct backup_label file or history file contents
+ *
+ * When ishistoryfile is true, it creates contents for backup history file,
+ * otherwise, it creates contents for backup_label file.
+ */
+void
+build_backup_content(BackupState *state, bool ishistoryfile, StringInfo str)
+{
+ char startstrbuf[128];
+ char startxlogfile[MAXFNAMELEN]; /* backup start WAL file */
+ XLogSegNo startsegno;
+
+ Assert(state != NULL);
+ Assert(str != NULL);
+
+ /* Use the log timezone here, not the session timezone */
+ pg_strftime(startstrbuf, sizeof(startstrbuf), "%Y-%m-%d %H:%M:%S %Z",
+ pg_localtime(&state->starttime, log_timezone));
+
+ XLByteToSeg(state->startpoint, startsegno, wal_segment_size);
+ XLogFileName(startxlogfile, state->starttli, startsegno, wal_segment_size);
+ appendStringInfo(str, "START WAL LOCATION: %X/%X (file %s)\n",
+ LSN_FORMAT_ARGS(state->startpoint), startxlogfile);
+
+ if (ishistoryfile)
+ {
+ char stopxlogfile[MAXFNAMELEN]; /* backup stop WAL file */
+ XLogSegNo stopsegno;
+
+ XLByteToSeg(state->startpoint, stopsegno, wal_segment_size);
+ XLogFileName(stopxlogfile, state->starttli, stopsegno, wal_segment_size);
+ appendStringInfo(str, "STOP WAL LOCATION: %X/%X (file %s)\n",
+ LSN_FORMAT_ARGS(state->startpoint), stopxlogfile);
+ }
+
+ appendStringInfo(str, "CHECKPOINT LOCATION: %X/%X\n",
+ LSN_FORMAT_ARGS(state->checkpointloc));
+ appendStringInfo(str, "BACKUP METHOD: streamed\n");
+ appendStringInfo(str, "BACKUP FROM: %s\n",
+ state->started_in_recovery ? "standby" : "primary");
+ appendStringInfo(str, "START TIME: %s\n", startstrbuf);
+ appendStringInfo(str, "LABEL: %s\n", state->name);
+ appendStringInfo(str, "START TIMELINE: %u\n", state->starttli);
+
+ if (ishistoryfile)
+ {
+ char stopstrfbuf[128];
+
+ /* Use the log timezone here, not the session timezone */
+ pg_strftime(stopstrfbuf, sizeof(stopstrfbuf), "%Y-%m-%d %H:%M:%S %Z",
+ pg_localtime(&state->stoptime, log_timezone));
+
+ appendStringInfo(str, "STOP TIME: %s\n", stopstrfbuf);
+ appendStringInfo(str, "STOP TIMELINE: %u\n", state->stoptli);
+ }
+}
diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c
index 27aeb6e281..e078579e6f 100644
--- a/src/backend/access/transam/xlogfuncs.c
+++ b/src/backend/access/transam/xlogfuncs.c
@@ -20,6 +20,7 @@
#include "access/htup_details.h"
#include "access/xlog_internal.h"
+#include <access/xlogbackup.h>
#include "access/xlogrecovery.h"
#include "access/xlogutils.h"
#include "catalog/pg_type.h"
@@ -39,19 +40,15 @@
#include "utils/tuplestore.h"
/*
- * Store label file and tablespace map during backups.
+ * Backup related variables.
*/
-static StringInfo label_file;
-static StringInfo tblspc_map_file;
+static BackupState *backup_state = NULL;
+static StringInfo tablespace_map = NULL;
/*
- * pg_backup_start: set up for taking an on-line backup dump
+ * pg_backup_start: start taking an on-line backup.
*
- * Essentially what this does is to create a backup label file in $PGDATA,
- * where it will be archived as part of the backup dump. The label file
- * contains the user-supplied label string (typically this would be used
- * to tell where the backup dump will be stored) and the starting time and
- * starting WAL location for the dump.
+ * This function starts the backup and creates tablespace_map contents.
*
* Permission checking for this function is managed through the normal
* GRANT system.
@@ -62,7 +59,6 @@ pg_backup_start(PG_FUNCTION_ARGS)
text *backupid = PG_GETARG_TEXT_PP(0);
bool fast = PG_GETARG_BOOL(1);
char *backupidstr;
- XLogRecPtr startpoint;
SessionBackupState status = get_backup_status();
MemoryContext oldcontext;
@@ -74,20 +70,33 @@ pg_backup_start(PG_FUNCTION_ARGS)
errmsg("a backup is already in progress in this session")));
/*
- * Label file and tablespace map file need to be long-lived, since they
- * are read in pg_backup_stop.
+ * backup_state and tablespace_map need to be long-lived as they are used
+ * in pg_backup_stop(), hence allocate in TopMemoryContext.
*/
oldcontext = MemoryContextSwitchTo(TopMemoryContext);
- label_file = makeStringInfo();
- tblspc_map_file = makeStringInfo();
+
+ if (backup_state == NULL)
+ backup_state = allocate_backup_state(backupidstr);
+ else
+ reset_backup_state(backup_state, backupidstr);
+
+ /*
+ * tablespace_map memory may have been enlarged previously, hence we free
+ * it up and allocate again instead of resetting to save some memory.
+ */
+ if (tablespace_map != NULL)
+ {
+ pfree(tablespace_map->data);
+ tablespace_map = NULL;
+ }
+
+ tablespace_map = makeStringInfo();
MemoryContextSwitchTo(oldcontext);
register_persistent_abort_backup_handler();
+ do_pg_backup_start(backup_state, fast, NULL, tablespace_map);
- startpoint = do_pg_backup_start(backupidstr, fast, NULL, label_file,
- NULL, tblspc_map_file);
-
- PG_RETURN_LSN(startpoint);
+ PG_RETURN_LSN(backup_state->startpoint);
}
@@ -98,6 +107,9 @@ pg_backup_start(PG_FUNCTION_ARGS)
* allows the user to choose if they want to wait for the WAL to be archived
* or if we should just return as soon as the WAL record is written.
*
+ * This function stops an in-progress backup, creates backup_label contents and
+ * it returns the backup stop LSN, backup_label and tablespace_map contents.
+ *
* Permission checking for this function is managed through the normal
* GRANT system.
*/
@@ -108,9 +120,8 @@ pg_backup_stop(PG_FUNCTION_ARGS)
TupleDesc tupdesc;
Datum values[PG_BACKUP_STOP_V2_COLS] = {0};
bool nulls[PG_BACKUP_STOP_V2_COLS] = {0};
-
bool waitforarchive = PG_GETARG_BOOL(0);
- XLogRecPtr stoppoint;
+ StringInfo backup_label;
SessionBackupState status = get_backup_status();
/* Initialize attributes information in the tuple descriptor */
@@ -123,23 +134,36 @@ pg_backup_stop(PG_FUNCTION_ARGS)
errmsg("backup is not in progress"),
errhint("Did you call pg_backup_start()?")));
+ /*
+ * Assert the fact that these backup variables are allocated in
+ * pg_backup_start().
+ */
+ Assert(backup_state != NULL);
+ Assert(tablespace_map != NULL);
+
/*
* Stop the backup. Return a copy of the backup label and tablespace map
* so they can be written to disk by the caller.
*/
- stoppoint = do_pg_backup_stop(label_file->data, waitforarchive, NULL);
-
- values[0] = LSNGetDatum(stoppoint);
- values[1] = CStringGetTextDatum(label_file->data);
- values[2] = CStringGetTextDatum(tblspc_map_file->data);
-
- /* Free structures allocated in TopMemoryContext */
- pfree(label_file->data);
- pfree(label_file);
- label_file = NULL;
- pfree(tblspc_map_file->data);
- pfree(tblspc_map_file);
- tblspc_map_file = NULL;
+ do_pg_backup_stop(backup_state, waitforarchive);
+
+ /*
+ * Construct backup_label contents. Note that the backup_label doesn't have
+ * to be in TopMemoryContext unlike backup_state and tablespace_map as it
+ * is short-lived.
+ */
+ backup_label = makeStringInfo();
+ build_backup_content(backup_state, false, backup_label);
+
+ values[0] = LSNGetDatum(backup_state->stoppoint);
+ values[1] = CStringGetTextDatum(backup_label->data);
+ values[2] = CStringGetTextDatum(tablespace_map->data);
+
+ /* Deallocate backup related variables. */
+ deallocate_backup_variables(backup_state, backup_label, tablespace_map);
+ backup_state = NULL;
+ backup_label = NULL;
+ tablespace_map = NULL;
/* Returns the record as Datum */
PG_RETURN_DATUM(HeapTupleGetDatum(heap_form_tuple(tupdesc, values, nulls)));
diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c
index 1f1cff1a58..7ba4f340bc 100644
--- a/src/backend/backup/basebackup.c
+++ b/src/backend/backup/basebackup.c
@@ -17,6 +17,7 @@
#include <time.h>
#include "access/xlog_internal.h"
+#include <access/xlogbackup.h>
#include "backup/backup_manifest.h"
#include "backup/basebackup.h"
#include "backup/basebackup_sink.h"
@@ -231,9 +232,10 @@ perform_base_backup(basebackup_options *opt, bbsink *sink)
bbsink_state state;
XLogRecPtr endptr;
TimeLineID endtli;
- StringInfo labelfile;
- StringInfo tblspc_map_file;
backup_manifest_info manifest;
+ BackupState *backup_state;
+ StringInfo backup_label;
+ StringInfo tablespace_map;
/* Initial backup state, insofar as we know it now. */
state.tablespaces = NIL;
@@ -248,18 +250,25 @@ perform_base_backup(basebackup_options *opt, bbsink *sink)
backup_started_in_recovery = RecoveryInProgress();
- labelfile = makeStringInfo();
- tblspc_map_file = makeStringInfo();
InitializeBackupManifest(&manifest, opt->manifest,
opt->manifest_checksum_type);
total_checksum_failures = 0;
+ /* Allocate backup related varilables. */
+ backup_state = allocate_backup_state(opt->label);
+ backup_label = makeStringInfo();
+ tablespace_map = makeStringInfo();
+
basebackup_progress_wait_checkpoint();
- state.startptr = do_pg_backup_start(opt->label, opt->fastcheckpoint,
- &state.starttli,
- labelfile, &state.tablespaces,
- tblspc_map_file);
+ do_pg_backup_start(backup_state, opt->fastcheckpoint,
+ &state.tablespaces, tablespace_map);
+
+ /* Construct backup_label contents. */
+ build_backup_content(backup_state, false, backup_label);
+
+ state.startptr = backup_state->startpoint;
+ state.starttli = backup_state->starttli;
/*
* Once do_pg_backup_start has been called, ensure that any failure causes
@@ -317,14 +326,14 @@ perform_base_backup(basebackup_options *opt, bbsink *sink)
bbsink_begin_archive(sink, "base.tar");
/* In the main tar, include the backup_label first... */
- sendFileWithContent(sink, BACKUP_LABEL_FILE, labelfile->data,
- &manifest);
+ sendFileWithContent(sink, BACKUP_LABEL_FILE,
+ backup_label->data, &manifest);
/* Then the tablespace_map file, if required... */
if (opt->sendtblspcmapfile)
{
- sendFileWithContent(sink, TABLESPACE_MAP, tblspc_map_file->data,
- &manifest);
+ sendFileWithContent(sink, TABLESPACE_MAP,
+ tablespace_map->data, &manifest);
sendtblspclinks = false;
}
@@ -374,7 +383,13 @@ perform_base_backup(basebackup_options *opt, bbsink *sink)
}
basebackup_progress_wait_wal_archive(&state);
- endptr = do_pg_backup_stop(labelfile->data, !opt->nowait, &endtli);
+ do_pg_backup_stop(backup_state, !opt->nowait);
+
+ endptr = backup_state->stoppoint;
+ endtli = backup_state->stoptli;
+
+ deallocate_backup_variables(backup_state, backup_label,
+ tablespace_map);
}
PG_END_ENSURE_ERROR_CLEANUP(do_pg_abort_backup, BoolGetDatum(false));
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 3dbfa6b593..5a47c5552b 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -11,6 +11,7 @@
#ifndef XLOG_H
#define XLOG_H
+#include <access/xlogbackup.h>
#include "access/xlogdefs.h"
#include "access/xlogreader.h"
#include "datatype/timestamp.h"
@@ -277,11 +278,9 @@ typedef enum SessionBackupState
SESSION_BACKUP_RUNNING,
} SessionBackupState;
-extern XLogRecPtr do_pg_backup_start(const char *backupidstr, bool fast,
- TimeLineID *starttli_p, StringInfo labelfile,
- List **tablespaces, StringInfo tblspcmapfile);
-extern XLogRecPtr do_pg_backup_stop(char *labelfile, bool waitforarchive,
- TimeLineID *stoptli_p);
+extern void do_pg_backup_start(BackupState *state, bool fast,
+ List **tablespaces, StringInfo tablespace_map);
+extern void do_pg_backup_stop(BackupState *state, bool waitforarchive);
extern void do_pg_abort_backup(int code, Datum arg);
extern void register_persistent_abort_backup_handler(void);
extern SessionBackupState get_backup_status(void);
diff --git a/src/include/access/xlogbackup.h b/src/include/access/xlogbackup.h
new file mode 100644
index 0000000000..5b43b7d1d7
--- /dev/null
+++ b/src/include/access/xlogbackup.h
@@ -0,0 +1,53 @@
+/*-------------------------------------------------------------------------
+ * xlogbackup.h
+ *
+ * Declarations for the backup related code.
+ *
+ * Copyright (c) 2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/include/access/xlogbackup.h
+ *-------------------------------------------------------------------------
+ */
+#ifndef XLOG_BACKUP_H
+#define XLOG_BACKUP_H
+
+#include "access/xlogdefs.h"
+#include "lib/stringinfo.h"
+#include "pgtime.h"
+
+/* Structure to hold backup state. */
+typedef struct BackupState
+{
+ /* Following are the fields captured when the backup starts. */
+
+ /*
+ * Null-terminated backup label name. If the label name is of size more
+ * than MAXPGPATH, an error is emitted in do_pg_backup_start(). We do not
+ * want to over-allocate memory in this structure, hence we truncate it to
+ * MAXPGPATH + 2 bytes (one extra byte for representing that the name has
+ * overflown, and another extra byte for null-termination).
+ */
+ char name[MAXPGPATH + 2];
+ XLogRecPtr startpoint; /* backup start WAL location */
+ TimeLineID starttli; /* backup start TLI */
+ XLogRecPtr checkpointloc; /* last checkpoint location */
+ pg_time_t starttime; /* backup start time */
+ bool started_in_recovery; /* backup started in recovery? */
+
+ /* Following are the fields captured during or after the backup stops. */
+
+ XLogRecPtr stoppoint; /* backup stop WAL location */
+ TimeLineID stoptli; /* backup stop TLI */
+ pg_time_t stoptime; /* backup stop time */
+} BackupState;
+
+extern BackupState *allocate_backup_state(const char *name);
+extern void reset_backup_state(BackupState *state, const char *name);
+extern void deallocate_backup_variables(BackupState *state,
+ StringInfo backup_label,
+ StringInfo tablespace_map);
+extern void build_backup_content(BackupState *state,
+ bool ishistoryfile,
+ StringInfo str);
+#endif /* XLOG_BACKUP_H */
--
2.34.1
From b20d5455f746ec8f2ca4bd325f8636aa2b991438 Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Date: Tue, 20 Sep 2022 10:44:42 +0000
Subject: [PATCH v9] Add error callbacks for deallocating backup related
variables
This adds error callbacks for deallocating backup related
variables to save on some palloc-ed memory upon errors while
taking backup.
---
src/backend/access/transam/xlogbackup.c | 22 ++++++++++
src/backend/access/transam/xlogfuncs.c | 54 +++++++++++++++++++++++++
src/backend/backup/basebackup.c | 14 +++++++
src/backend/utils/error/elog.c | 17 ++++++++
src/include/access/xlogbackup.h | 11 +++++
src/include/utils/elog.h | 1 +
6 files changed, 119 insertions(+)
diff --git a/src/backend/access/transam/xlogbackup.c b/src/backend/access/transam/xlogbackup.c
index 38c37cc7db..39210af41b 100644
--- a/src/backend/access/transam/xlogbackup.c
+++ b/src/backend/access/transam/xlogbackup.c
@@ -92,6 +92,28 @@ deallocate_backup_variables(BackupState *state, StringInfo backup_label,
pfree(tablespace_map->data);
}
+/*
+ * Erro callback for deallocating backup variables.
+ */
+void
+deallocate_backup_variables_err_cb(void *arg)
+{
+ BackupErrorInfo *errinfo = (BackupErrorInfo *) arg;
+
+ /*
+ * Since error callbacks are called for elevel lesser than ERROR, we
+ * proceed further only if elevel is ERROR or greater.
+ */
+ if (geterrlevel() < ERROR)
+ return;
+
+ if (errinfo == NULL)
+ return; /* nothing to do */
+
+ deallocate_backup_variables(errinfo->state, errinfo->backup_label,
+ errinfo->tablespace_map);
+}
+
/*
* Construct backup_label file or history file contents
*
diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c
index e078579e6f..7d801aefc7 100644
--- a/src/backend/access/transam/xlogfuncs.c
+++ b/src/backend/access/transam/xlogfuncs.c
@@ -45,6 +45,32 @@
static BackupState *backup_state = NULL;
static StringInfo tablespace_map = NULL;
+/*
+ * Erro callback for deallocating and resetting backup variables.
+ */
+static void
+deallocate_and_reset_backup_variables_err_cb(void *arg)
+{
+ BackupErrorInfo *errinfo = (BackupErrorInfo *) arg;
+
+ /*
+ * Since error callbacks are called for elevel lesser than ERROR, we
+ * proceed further only if elevel is ERROR or greater.
+ */
+ if (geterrlevel() < ERROR)
+ return;
+
+ if (errinfo == NULL)
+ return; /* nothing to do */
+
+ deallocate_backup_variables(errinfo->state, errinfo->backup_label,
+ errinfo->tablespace_map);
+
+ /* Reset the static variables. */
+ backup_state = NULL;
+ tablespace_map = NULL;
+}
+
/*
* pg_backup_start: start taking an on-line backup.
*
@@ -61,6 +87,8 @@ pg_backup_start(PG_FUNCTION_ARGS)
char *backupidstr;
SessionBackupState status = get_backup_status();
MemoryContext oldcontext;
+ ErrorContextCallback errcallback;
+ BackupErrorInfo errinfo;
backupidstr = text_to_cstring(backupid);
@@ -93,9 +121,21 @@ pg_backup_start(PG_FUNCTION_ARGS)
tablespace_map = makeStringInfo();
MemoryContextSwitchTo(oldcontext);
+ /* Set up callback to clean up backup related variables */
+ errcallback.callback = deallocate_and_reset_backup_variables_err_cb;
+ errinfo.state = backup_state;
+ errinfo.backup_label = NULL;
+ errinfo.tablespace_map = tablespace_map;
+ errcallback.arg = (void *) &errinfo;
+ errcallback.previous = error_context_stack;
+ error_context_stack = &errcallback;
+
register_persistent_abort_backup_handler();
do_pg_backup_start(backup_state, fast, NULL, tablespace_map);
+ /* Pop the error context stack */
+ error_context_stack = errcallback.previous;
+
PG_RETURN_LSN(backup_state->startpoint);
}
@@ -123,6 +163,8 @@ pg_backup_stop(PG_FUNCTION_ARGS)
bool waitforarchive = PG_GETARG_BOOL(0);
StringInfo backup_label;
SessionBackupState status = get_backup_status();
+ ErrorContextCallback errcallback;
+ BackupErrorInfo errinfo;
/* Initialize attributes information in the tuple descriptor */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
@@ -141,12 +183,24 @@ pg_backup_stop(PG_FUNCTION_ARGS)
Assert(backup_state != NULL);
Assert(tablespace_map != NULL);
+ /* Set up callback to clean up backup related variables */
+ errcallback.callback = deallocate_and_reset_backup_variables_err_cb;
+ errinfo.state = backup_state;
+ errinfo.backup_label = NULL;
+ errinfo.tablespace_map = tablespace_map;
+ errcallback.arg = (void *) &errinfo;
+ errcallback.previous = error_context_stack;
+ error_context_stack = &errcallback;
+
/*
* Stop the backup. Return a copy of the backup label and tablespace map
* so they can be written to disk by the caller.
*/
do_pg_backup_stop(backup_state, waitforarchive);
+ /* Pop the error context stack */
+ error_context_stack = errcallback.previous;
+
/*
* Construct backup_label contents. Note that the backup_label doesn't have
* to be in TopMemoryContext unlike backup_state and tablespace_map as it
diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c
index 7ba4f340bc..3edbe4c460 100644
--- a/src/backend/backup/basebackup.c
+++ b/src/backend/backup/basebackup.c
@@ -236,6 +236,8 @@ perform_base_backup(basebackup_options *opt, bbsink *sink)
BackupState *backup_state;
StringInfo backup_label;
StringInfo tablespace_map;
+ ErrorContextCallback errcallback;
+ BackupErrorInfo errinfo;
/* Initial backup state, insofar as we know it now. */
state.tablespaces = NIL;
@@ -260,6 +262,15 @@ perform_base_backup(basebackup_options *opt, bbsink *sink)
backup_label = makeStringInfo();
tablespace_map = makeStringInfo();
+ /* Set up callback to clean up backup related variables */
+ errcallback.callback = deallocate_backup_variables_err_cb;
+ errinfo.state = backup_state;
+ errinfo.backup_label = backup_label;
+ errinfo.tablespace_map = tablespace_map;
+ errcallback.arg = (void *) &errinfo;
+ errcallback.previous = error_context_stack;
+ error_context_stack = &errcallback;
+
basebackup_progress_wait_checkpoint();
do_pg_backup_start(backup_state, opt->fastcheckpoint,
&state.tablespaces, tablespace_map);
@@ -663,6 +674,9 @@ perform_base_backup(basebackup_options *opt, bbsink *sink)
/* clean up the resource owner we created */
WalSndResourceCleanup(true);
+ /* Pop the error context stack */
+ error_context_stack = errcallback.previous;
+
basebackup_progress_done();
}
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 96c694da8f..d2868648db 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -1404,6 +1404,23 @@ geterrcode(void)
return edata->sqlerrcode;
}
+/*
+ * geterrlevel --- return the currently error level
+ *
+ * This is only intended for use in error callback subroutines, since there
+ * is no other place outside elog.c where the concept is meaningful.
+ */
+int
+geterrlevel(void)
+{
+ ErrorData *edata = &errordata[errordata_stack_depth];
+
+ /* we don't bother incrementing recursion_depth */
+ CHECK_STACK_DEPTH();
+
+ return edata->elevel;
+}
+
/*
* geterrposition --- return the currently set error position (0 if none)
*
diff --git a/src/include/access/xlogbackup.h b/src/include/access/xlogbackup.h
index 5b43b7d1d7..e98fe6132c 100644
--- a/src/include/access/xlogbackup.h
+++ b/src/include/access/xlogbackup.h
@@ -42,6 +42,16 @@ typedef struct BackupState
pg_time_t stoptime; /* backup stop time */
} BackupState;
+/*
+ * Structure to hold input parameters for backup error callback.
+ */
+typedef struct BackupErrorInfo
+{
+ BackupState *state;
+ StringInfo backup_label;
+ StringInfo tablespace_map;
+} BackupErrorInfo;
+
extern BackupState *allocate_backup_state(const char *name);
extern void reset_backup_state(BackupState *state, const char *name);
extern void deallocate_backup_variables(BackupState *state,
@@ -50,4 +60,5 @@ extern void deallocate_backup_variables(BackupState *state,
extern void build_backup_content(BackupState *state,
bool ishistoryfile,
StringInfo str);
+extern void deallocate_backup_variables_err_cb(void *arg);
#endif /* XLOG_BACKUP_H */
diff --git a/src/include/utils/elog.h b/src/include/utils/elog.h
index 4dd9658a3c..a8955f9572 100644
--- a/src/include/utils/elog.h
+++ b/src/include/utils/elog.h
@@ -222,6 +222,7 @@ extern int internalerrquery(const char *query);
extern int err_generic_string(int field, const char *str);
extern int geterrcode(void);
+extern int geterrlevel(void);
extern int geterrposition(void);
extern int getinternalerrposition(void);
--
2.34.1
