postgres.git / summary / log / commit / refs

commit    6737aa72ba7621d4db8e09210c65eecafc42b616
Author:   Alvaro Herrera <alvherre@alvh.no-ip.org>
Date:     Fri Jul 19 22:35:07 2013 +0000
First released in: 9.4.0, 9.3.0

    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 55563ea335d..c69ffd306ed 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;


[parent: c8fb821afc2c]