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_2_STABLE Details ------- http://git.postgresql.org/pg/commitdiff/d3f5d2892bc7f48adce4116d7f99f75214544934 Modified Files -------------- src/backend/access/transam/twophase.c | 6 ++++++ 1 file changed, 6 insertions(+)