Save errno across LWLockRelease() calls

Fixup for "Drop slot's LWLock before returning from SaveSlotToPath()"

Reported-by: Michael Paquier <michael@paquier.xyz>
This commit is contained in:
Peter Eisentraut 2020-04-05 10:02:00 +02:00
parent 0912fb39ca
commit 250041a561

View File

@ -1260,9 +1260,13 @@ SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel)
/* /*
* If not an ERROR, then release the lock before returning. In case * If not an ERROR, then release the lock before returning. In case
* of an ERROR, the error recovery path automatically releases the * 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); LWLockRelease(&slot->io_in_progress_lock);
errno = save_errno;
ereport(elevel, ereport(elevel,
(errcode_for_file_access(), (errcode_for_file_access(),
errmsg("could not create file \"%s\": %m", 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 */ /* rename to permanent file, fsync file and directory */
if (rename(tmppath, path) != 0) if (rename(tmppath, path) != 0)
{ {
int save_errno = errno;
LWLockRelease(&slot->io_in_progress_lock); LWLockRelease(&slot->io_in_progress_lock);
errno = save_errno;
ereport(elevel, ereport(elevel,
(errcode_for_file_access(), (errcode_for_file_access(),
errmsg("could not rename file \"%s\" to \"%s\": %m", errmsg("could not rename file \"%s\" to \"%s\": %m",