From 250041a561a8cf34d981b2adbcf4b3b8030e24fd Mon Sep 17 00:00:00 2001 From: Peter Eisentraut Date: Sun, 5 Apr 2020 10:02:00 +0200 Subject: [PATCH] Save errno across LWLockRelease() calls Fixup for "Drop slot's LWLock before returning from SaveSlotToPath()" Reported-by: Michael Paquier --- src/backend/replication/slot.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c index 6499162f37..1317522fbb 100644 --- a/src/backend/replication/slot.c +++ b/src/backend/replication/slot.c @@ -1260,9 +1260,13 @@ SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel) /* * 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. + * lock, but no harm in explicitly releasing even in that case. Note + * that LWLockRelease() could affect errno. */ + int save_errno = errno; + LWLockRelease(&slot->io_in_progress_lock); + errno = save_errno; ereport(elevel, (errcode_for_file_access(), errmsg("could not create file \"%s\": %m", @@ -1329,7 +1333,10 @@ SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel) /* rename to permanent file, fsync file and directory */ if (rename(tmppath, path) != 0) { + int save_errno = errno; + LWLockRelease(&slot->io_in_progress_lock); + errno = save_errno; ereport(elevel, (errcode_for_file_access(), errmsg("could not rename file \"%s\" to \"%s\": %m",