diff options
Diffstat (limited to 'src/backend/access/transam/xlog.c')
| -rw-r--r-- | src/backend/access/transam/xlog.c | 36 |
1 files changed, 32 insertions, 4 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 0791404263e..3e9a12dacdd 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -10628,13 +10628,20 @@ do_pg_start_backup(const char *backupidstr, bool fast, TimeLineID *starttli_p, /* * Mark that start phase has correctly finished for an exclusive backup. * Session-level locks are updated as well to reflect that state. + * + * Note that CHECK_FOR_INTERRUPTS() must not occur while updating + * backup counters and session-level lock. Otherwise they can be + * updated inconsistently, and which might cause do_pg_abort_backup() + * to fail. */ if (exclusive) { WALInsertLockAcquireExclusive(); XLogCtl->Insert.exclusiveBackupState = EXCLUSIVE_BACKUP_IN_PROGRESS; - WALInsertLockRelease(); + + /* Set session-level lock */ sessionBackupState = SESSION_BACKUP_EXCLUSIVE; + WALInsertLockRelease(); } else sessionBackupState = SESSION_BACKUP_NON_EXCLUSIVE; @@ -10838,7 +10845,11 @@ do_pg_stop_backup(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p) } /* - * OK to update backup counters and forcePageWrites + * OK to update backup counters, forcePageWrites and session-level lock. + * + * Note that CHECK_FOR_INTERRUPTS() must not occur while updating them. + * Otherwise they can be updated inconsistently, and which might cause + * do_pg_abort_backup() to fail. */ WALInsertLockAcquireExclusive(); if (exclusive) @@ -10862,11 +10873,20 @@ do_pg_stop_backup(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p) { XLogCtl->Insert.forcePageWrites = false; } - WALInsertLockRelease(); - /* Clean up session-level lock */ + /* + * Clean up session-level lock. + * + * You might think that WALInsertLockRelease() can be called + * before cleaning up session-level lock because session-level + * lock doesn't need to be protected with WAL insertion lock. + * But since CHECK_FOR_INTERRUPTS() can occur in it, + * session-level lock must be cleaned up before it. + */ sessionBackupState = SESSION_BACKUP_NONE; + 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). @@ -11104,8 +11124,16 @@ do_pg_stop_backup(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p) void do_pg_abort_backup(void) { + /* + * Quick exit if session is not keeping around a non-exclusive backup + * already started. + */ + if (sessionBackupState == SESSION_BACKUP_NONE) + return; + WALInsertLockAcquireExclusive(); Assert(XLogCtl->Insert.nonExclusiveBackups > 0); + Assert(sessionBackupState == SESSION_BACKUP_NON_EXCLUSIVE); XLogCtl->Insert.nonExclusiveBackups--; if (XLogCtl->Insert.exclusiveBackupState == EXCLUSIVE_BACKUP_NONE && |