diff options
| author | Thomas Munro <tmunro@postgresql.org> | 2020-06-08 13:57:24 +1200 |
|---|---|---|
| committer | Thomas Munro <tmunro@postgresql.org> | 2020-06-08 14:01:51 +1200 |
| commit | 644cac32a0bcfb1749e82c17f2d01d1b6aad8207 (patch) | |
| tree | bb05f5cd495e913e00246c84d759ac67f3732fb5 | |
| parent | 5c28a7bf1c57756e8992c2a6a083a34109f38323 (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
| -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 cec8c4c629d..02e18d48525 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -9318,6 +9318,8 @@ 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; @@ -9326,6 +9328,8 @@ XLogReportParameters(void) ControlFile->wal_log_hints = wal_log_hints; ControlFile->track_commit_timestamp = track_commit_timestamp; UpdateControlFile(); + + LWLockRelease(ControlFileLock); } } @@ -9545,8 +9549,10 @@ 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); @@ -9604,8 +9610,10 @@ 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); |