From d278d4e1adc14998948656d16e759f70c0fafb66 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 | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c index 409db4b2ef..bb5555ed73 100644 --- a/src/backend/replication/slot.c +++ b/src/backend/replication/slot.c @@ -1259,9 +1259,13 @@ 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", @@ -1325,7 +1329,10 @@ SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel) if (CloseTransientFile(fd)) { + int save_errno = errno; + LWLockRelease(&slot->io_in_progress_lock); + errno = save_errno; ereport(elevel, (errcode_for_file_access(), errmsg("could not close file \"%s\": %m", @@ -1336,7 +1343,10 @@ 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",