From a45c70acf35e43257d86313dcbb7bb0e5201fab1 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Sun, 28 Jun 2015 21:59:29 +0300 Subject: Fix double-XLogBeginInsert call in GIN page splits. If data checksums or wal_log_hints is on, and a GIN page is split, the code to find a new, empty, block was called after having already called XLogBeginInsert(). That causes an assertion failure or PANIC, if finding the new block involves updating a FSM page that had not been modified since last checkpoint, because that update is WAL-logged, which calls XLogBeginInsert again. Nested XLogBeginInsert calls are not supported. To fix, rearrange GIN code so that XLogBeginInsert is called later, after finding the victim buffers. Reported by Jeff Janes. --- src/backend/access/gin/ginbtree.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) (limited to 'src/backend/access/gin/ginbtree.c') diff --git a/src/backend/access/gin/ginbtree.c b/src/backend/access/gin/ginbtree.c index 3f92c56d3c0..f0ff91aba2f 100644 --- a/src/backend/access/gin/ginbtree.c +++ b/src/backend/access/gin/ginbtree.c @@ -358,20 +358,15 @@ ginPlaceToPage(GinBtree btree, GinBtreeStack *stack, * placeToPage can register some data to the WAL record. * * If placeToPage returns INSERTED, placeToPage has already called - * START_CRIT_SECTION(), and we're responsible for calling - * END_CRIT_SECTION. When it returns INSERTED, it is also responsible for - * registering any data required to replay the operation with - * XLogRegisterData(0, ...). It may only add data to block index 0; the - * main data of the WAL record is reserved for this function. + * START_CRIT_SECTION() and XLogBeginInsert(), and registered any data + * required to replay the operation, in block index 0. We're responsible + * for filling in the main data portion of the WAL record, calling + * XLogInsert(), and END_CRIT_SECTION. * * If placeToPage returns SPLIT, we're wholly responsible for WAL logging. * Splits happen infrequently, so we just make a full-page image of all * the pages involved. */ - - if (RelationNeedsWAL(btree->index)) - XLogBeginInsert(); - rc = btree->placeToPage(btree, stack->buffer, stack, insertdata, updateblkno, &newlpage, &newrpage); @@ -558,6 +553,8 @@ ginPlaceToPage(GinBtree btree, GinBtreeStack *stack, { XLogRecPtr recptr; + XLogBeginInsert(); + /* * We just take full page images of all the split pages. Splits * are uncommon enough that it's not worth complicating the code -- cgit v1.2.3