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| author | Thomas Munro <tmunro@postgresql.org> | 2020-06-08 13:57:24 +1200 |
|---|---|---|
| committer | Thomas Munro <tmunro@postgresql.org> | 2020-06-08 13:59:57 +1200 |
| commit | 48eb6a3c895dac239f7e04fc3d62c09a17c1fc4a (patch) | |
| tree | b65a746af5e931c04970e87c158b18115d944464 | |
| parent | a35896c4b2a18b84f35c2cc6a9f5aee6ba041c43 (diff) | |
| download | postgresql-48eb6a3c895dac239f7e04fc3d62c09a17c1fc4a.tar.gz postgresql-48eb6a3c895dac239f7e04fc3d62c09a17c1fc4a.zip | |
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 28f19f1c786..bceef897d6e 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -9680,6 +9680,8 @@ 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; @@ -9688,6 +9690,8 @@ XLogReportParameters(void) ControlFile->wal_log_hints = wal_log_hints; ControlFile->track_commit_timestamp = track_commit_timestamp; UpdateControlFile(); + + LWLockRelease(ControlFileLock); } } @@ -9912,8 +9916,10 @@ 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); @@ -9971,8 +9977,10 @@ 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); |