Thread: pgsql: Fix deadlock at startup, if max_prepared_transactions is too sma
pgsql: Fix deadlock at startup, if max_prepared_transactions is too sma
From
Heikki Linnakangas
Date:
Fix deadlock at startup, if max_prepared_transactions is too small. When the startup process recovers transactions by scanning pg_twophase directory, it should clear MyLockedGxact after it's done processing each transaction. Like we do during normal operation, at PREPARE TRANSACTION. Otherwise, if the startup process exits due to an error, it will try to clear the locking_backend field of the last recovered transaction. That's usually harmless, but if the error happens in MarkAsPreparing, while holding TwoPhaseStateLock, the shmem-exit hook will try to acquire TwoPhaseStateLock again, and deadlock with itself. This fixes bug #13128 reported by Grant McAlister. The bug was introduced by commit bb38fb0d, so backpatch to all supported versions like that commit. Branch ------ REL9_1_STABLE Details ------- http://git.postgresql.org/pg/commitdiff/e8528a8f5d411f0d9a1a9f927eae332992949aa1 Modified Files -------------- src/backend/access/transam/twophase.c | 6 ++++++ 1 file changed, 6 insertions(+)