Avoid possible deadlock while locking multiple heap pages. To avoid deadlock, backend acquires a lock on heap pages in block number order. In certain cases, lock on heap pages is dropped and reacquired. In this case, the locks are dropped for reading in corresponding VM page/s. The issue is we re-acquire locks in bufferId order whereas the intention was to acquire in blockid order.
This commit ensures that we will always acquire locks on heap pages in blockid order. Reported-by: Nishant Fnu Author: Nishant Fnu Reviewed-by: Amit Kapila and Robert Haas Backpatch-through: 9.4 Discussion: https://postgr.es/m/[email protected] Branch ------ REL9_4_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/fba0a8292997c84f1642c8a8c601a24ffe1ed1f7 Modified Files -------------- src/backend/access/heap/hio.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
