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| author | Peter Eisentraut <peter@eisentraut.org> | 2020-03-26 11:51:39 +0100 |
|---|---|---|
| committer | Peter Eisentraut <peter@eisentraut.org> | 2020-03-26 13:51:07 +0100 |
| commit | ba4cc05ce22d8b83194f46085f54c23b7e2f448c (patch) | |
| tree | 53d2a2a16488fa4b7c78a56250665f7de0f36ab1 /src | |
| parent | 58995db07e374c2878960e0516acc49683ea102b (diff) | |
| download | postgresql-ba4cc05ce22d8b83194f46085f54c23b7e2f448c.tar.gz postgresql-ba4cc05ce22d8b83194f46085f54c23b7e2f448c.zip | |
Drop slot's LWLock before returning from SaveSlotToPath()
When SaveSlotToPath() is called with elevel=LOG, the early exits didn't
release the slot's io_in_progress_lock.
This could result in a walsender being stuck on the lock forever. A
possible way to get into this situation is if the offending code paths
are triggered in a low disk space situation.
Author: Pavan Deolasee <pavan.deolasee@2ndquadrant.com>
Reported-by: Craig Ringer <craig@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/56a138c5-de61-f553-7e8f-6789296de785%402ndquadrant.com
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/replication/slot.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c index 0392f37e198..6499162f377 100644 --- a/src/backend/replication/slot.c +++ b/src/backend/replication/slot.c @@ -1257,6 +1257,12 @@ SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel) fd = OpenTransientFile(tmppath, O_CREAT | O_EXCL | O_WRONLY | PG_BINARY); if (fd < 0) { + /* + * If not an ERROR, then release the lock before returning. In case + * of an ERROR, the error recovery path automatically releases the + * lock, but no harm in explicitly releasing even in that case. + */ + LWLockRelease(&slot->io_in_progress_lock); ereport(elevel, (errcode_for_file_access(), errmsg("could not create file \"%s\": %m", @@ -1288,6 +1294,7 @@ SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel) pgstat_report_wait_end(); CloseTransientFile(fd); + LWLockRelease(&slot->io_in_progress_lock); /* if write didn't set errno, assume problem is no disk space */ errno = save_errno ? save_errno : ENOSPC; @@ -1307,6 +1314,7 @@ SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel) pgstat_report_wait_end(); CloseTransientFile(fd); + LWLockRelease(&slot->io_in_progress_lock); errno = save_errno; ereport(elevel, (errcode_for_file_access(), @@ -1321,6 +1329,7 @@ SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel) /* rename to permanent file, fsync file and directory */ if (rename(tmppath, path) != 0) { + LWLockRelease(&slot->io_in_progress_lock); ereport(elevel, (errcode_for_file_access(), errmsg("could not rename file \"%s\" to \"%s\": %m", |