diff options
| author | Thomas Munro <tmunro@postgresql.org> | 2020-06-08 13:57:24 +1200 |
|---|---|---|
| committer | Thomas Munro <tmunro@postgresql.org> | 2020-06-08 14:01:07 +1200 |
| commit | fd11b842eba944d62014f7072b0c76e36cbe652e (patch) | |
| tree | cd26bb9782c209b215062cd66c7a909372682ab9 /src | |
| parent | 682c28baf9251a1406bfcad15243c8fca6594742 (diff) | |
Fix locking bugs that could corrupt pg_control.
The redo routines for XLOG_CHECKPOINT_{ONLINE,SHUTDOWN} must acquire
ControlFileLock before modifying ControlFile->checkPointCopy, or the
checkpointer could write out a control file with a bad checksum.
Likewise, XLogReportParameters() must acquire ControlFileLock before
modifying ControlFile and calling UpdateControlFile().
Back-patch to all supported releases.
Author: Nathan Bossart <bossartn@amazon.com>
Author: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/70BF24D6-DC51-443F-B55A-95735803842A%40amazon.com
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/access/transam/xlog.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 7c40b1a5111..7ab920a55d0 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -9647,6 +9647,8 @@ XLogReportParameters(void) XLogFlush(recptr); } + LWLockAcquire(ControlFileLock, LW_EXCLUSIVE); + ControlFile->MaxConnections = MaxConnections; ControlFile->max_worker_processes = max_worker_processes; ControlFile->max_prepared_xacts = max_prepared_xacts; @@ -9655,6 +9657,8 @@ XLogReportParameters(void) ControlFile->wal_log_hints = wal_log_hints; ControlFile->track_commit_timestamp = track_commit_timestamp; UpdateControlFile(); + + LWLockRelease(ControlFileLock); } } @@ -9879,8 +9883,10 @@ xlog_redo(XLogReaderState *record) } /* ControlFile->checkPointCopy always tracks the latest ckpt XID */ + LWLockAcquire(ControlFileLock, LW_EXCLUSIVE); ControlFile->checkPointCopy.nextXidEpoch = checkPoint.nextXidEpoch; ControlFile->checkPointCopy.nextXid = checkPoint.nextXid; + LWLockRelease(ControlFileLock); /* Update shared-memory copy of checkpoint XID/epoch */ SpinLockAcquire(&XLogCtl->info_lck); @@ -9938,8 +9944,10 @@ xlog_redo(XLogReaderState *record) SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB); /* ControlFile->checkPointCopy always tracks the latest ckpt XID */ + LWLockAcquire(ControlFileLock, LW_EXCLUSIVE); ControlFile->checkPointCopy.nextXidEpoch = checkPoint.nextXidEpoch; ControlFile->checkPointCopy.nextXid = checkPoint.nextXid; + LWLockRelease(ControlFileLock); /* Update shared-memory copy of checkpoint XID/epoch */ SpinLockAcquire(&XLogCtl->info_lck); |