From 6737aa72ba7621d4db8e09210c65eecafc42b616 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Fri, 19 Jul 2013 18:35:07 -0400 Subject: [PATCH] Fix HeapTupleSatisfiesVacuum on aborted updater xacts By using only the macro that checks infomask bits HEAP_XMAX_IS_LOCKED_ONLY to verify whether a multixact is not an updater, and not the full HeapTupleHeaderIsOnlyLocked, it would come to the wrong result in case of a multixact containing an aborted update; therefore returning the wrong result code. This would cause predicate.c to break completely (as in bug report #8273 from David Leverton), and certain index builds would misbehave. As far as I can tell, other callers of the bogus routine would make harmless mistakes or not be affected by the difference at all; so this was a pretty narrow case. Also, no other user of the HEAP_XMAX_IS_LOCKED_ONLY macro is as careless; they all check specifically for the HEAP_XMAX_IS_MULTI case, and they all verify whether the updater is InvalidXid before concluding that it's a valid updater. So there doesn't seem to be any similar bug. --- src/backend/utils/time/tqual.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/backend/utils/time/tqual.c b/src/backend/utils/time/tqual.c index 55563ea335..c69ffd306e 100644 --- a/src/backend/utils/time/tqual.c +++ b/src/backend/utils/time/tqual.c @@ -1287,7 +1287,9 @@ HeapTupleSatisfiesVacuum(HeapTupleHeader tuple, TransactionId OldestXmin, { if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */ return HEAPTUPLE_INSERT_IN_PROGRESS; - if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask)) + /* only locked? run infomask-only check first, for performance */ + if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask) || + HeapTupleHeaderIsOnlyLocked(tuple)) return HEAPTUPLE_INSERT_IN_PROGRESS; /* inserted and then deleted by same xact */ return HEAPTUPLE_DELETE_IN_PROGRESS;