diff options
| -rw-r--r-- | src/backend/access/nbtree/nbtpage.c | 62 | ||||
| -rw-r--r-- | src/backend/access/nbtree/nbtree.c | 3 |
2 files changed, 45 insertions, 20 deletions
diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c index 6be8915229e..486d1563d8a 100644 --- a/src/backend/access/nbtree/nbtpage.c +++ b/src/backend/access/nbtree/nbtpage.c @@ -2404,24 +2404,22 @@ _bt_unlink_halfdead_page(Relation rel, Buffer leafbuf, BlockNumber scanblkno, if (!leftsibvalid) { - if (target != leafblkno) - { - /* we have only a pin on target, but pin+lock on leafbuf */ - ReleaseBuffer(buf); - _bt_relbuf(rel, leafbuf); - } - else - { - /* we have only a pin on leafbuf */ - ReleaseBuffer(leafbuf); - } - + /* + * This is known to fail in the field; sibling link corruption + * is relatively common. Press on with vacuuming rather than + * just throwing an ERROR. + */ ereport(LOG, (errcode(ERRCODE_INDEX_CORRUPTED), errmsg_internal("valid left sibling for deletion target could not be located: " - "left sibling %u of target %u with leafblkno %u and scanblkno %u in index \"%s\"", + "left sibling %u of target %u with leafblkno %u and scanblkno %u on level %u of index \"%s\"", leftsib, target, leafblkno, scanblkno, - RelationGetRelationName(rel)))); + targetlevel, RelationGetRelationName(rel)))); + + /* Must release all pins and locks on failure exit */ + ReleaseBuffer(buf); + if (target != leafblkno) + _bt_relbuf(rel, leafbuf); return false; } @@ -2496,13 +2494,40 @@ _bt_unlink_halfdead_page(Relation rel, Buffer leafbuf, BlockNumber scanblkno, rbuf = _bt_getbuf(rel, vstate->info->heaprel, rightsib, BT_WRITE); page = BufferGetPage(rbuf); opaque = BTPageGetOpaque(page); + + /* + * Validate target's right sibling page. Its left link must point back to + * the target page. + */ if (opaque->btpo_prev != target) - ereport(ERROR, + { + /* + * This is known to fail in the field; sibling link corruption is + * relatively common. Press on with vacuuming rather than just + * throwing an ERROR (same approach used for left-sibling's-right-link + * validation check a moment ago). + */ + ereport(LOG, (errcode(ERRCODE_INDEX_CORRUPTED), errmsg_internal("right sibling's left-link doesn't match: " - "block %u links to %u instead of expected %u in index \"%s\"", - rightsib, opaque->btpo_prev, target, - RelationGetRelationName(rel)))); + "right sibling %u of target %u with leafblkno %u " + "and scanblkno %u spuriously links to non-target %u " + "on level %u of index \"%s\"", + rightsib, target, leafblkno, + scanblkno, opaque->btpo_prev, + targetlevel, RelationGetRelationName(rel)))); + + /* Must release all pins and locks on failure exit */ + if (BufferIsValid(lbuf)) + _bt_relbuf(rel, lbuf); + _bt_relbuf(rel, rbuf); + _bt_relbuf(rel, buf); + if (target != leafblkno) + _bt_relbuf(rel, leafbuf); + + return false; + } + rightsib_is_rightmost = P_RIGHTMOST(opaque); *rightsib_empty = (P_FIRSTDATAKEY(opaque) > PageGetMaxOffsetNumber(page)); @@ -2727,6 +2752,7 @@ _bt_unlink_halfdead_page(Relation rel, Buffer leafbuf, BlockNumber scanblkno, */ _bt_pendingfsm_add(vstate, target, safexid); + /* Success - hold on to lock on leafbuf (might also have been target) */ return true; } diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c index 2df8849858e..1ce5b15199a 100644 --- a/src/backend/access/nbtree/nbtree.c +++ b/src/backend/access/nbtree/nbtree.c @@ -1093,8 +1093,7 @@ backtrack: * can't be half-dead because only an interrupted VACUUM process can * leave pages in that state, so we'd definitely have dealt with it * back when the page was the scanblkno page (half-dead pages are - * always marked fully deleted by _bt_pagedel()). This assumes that - * there can be only one vacuum process running at a time. + * always marked fully deleted by _bt_pagedel(), barring corruption). */ if (!opaque || !P_ISLEAF(opaque) || P_ISHALFDEAD(opaque)) { |