Thread: pgsql: Fix race condition in invalidating obsolete replication slots
Fix race condition in invalidating obsolete replication slots The code added to mark replication slots invalid in commit c6550776394e had the race condition that a slot can be dropped or advanced concurrently with checkpointer trying to invalidate it. Rewrite the code to close those races. The changes to ReplicationSlotAcquire's API added with c6550776394e are not necessary anymore. To avoid an ABI break in released branches, this commit leaves that unchanged; it'll be changed in a master-only commit separately. Backpatch to 13, where this code first appeared. Reported-by: Andres Freund <andres@anarazel.de> Author: Andres Freund <andres@anarazel.de> Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20210408001037.wfmk6jud36auhfqm@alap3.anarazel.de Branch ------ REL_13_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/218b101008b533156d7e5832fe143d1e04a01301 Modified Files -------------- src/backend/replication/slot.c | 223 +++++++++++++++++++++++++++-------------- 1 file changed, 145 insertions(+), 78 deletions(-)