From 978da2a95597c97c52b14a27ba29873051ffc59d Mon Sep 17 00:00:00 2001 From: Noah Misch Date: Sat, 21 Mar 2020 09:38:26 -0700 Subject: During heap rebuild, lock any TOAST index until end of transaction. swap_relation_files() calls toast_get_valid_index() to find and lock this index, just before swapping with the rebuilt TOAST index. The latter function releases the lock before returning. Potential for mischief is low; a concurrent session can issue ALTER INDEX ... SET (fillfactor = ...), which is not alarming. Nonetheless, changing pg_class.relfilenode without a lock is unconventional. Back-patch to 9.5 (all supported versions), because another fix needs this. Discussion: https://postgr.es/m/20191226001521.GA1772687@rfd.leadboat.com --- src/backend/commands/cluster.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/backend/commands/cluster.c') diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c index 9c91f2c31f7..1c90f8c3382 100644 --- a/src/backend/commands/cluster.c +++ b/src/backend/commands/cluster.c @@ -1614,7 +1614,7 @@ finish_heap_swap(Oid OIDOldHeap, Oid OIDNewHeap, /* Get the associated valid index to be renamed */ toastidx = toast_get_valid_index(newrel->rd_rel->reltoastrelid, - AccessShareLock); + NoLock); /* rename the toast table ... */ snprintf(NewToastName, NAMEDATALEN, "pg_toast_%u", -- cgit v1.2.3