From ae1f9b0a9bc3d2d1e46fcd38c8b2e7ba49238b05 Mon Sep 17 00:00:00 2001 From: Alexander Korotkov Date: Wed, 6 May 2020 15:35:27 +0300 Subject: [PATCH] Fix amcheck for page checks concurrent to replay of btree page deletion amcheck expects at least hikey to always exist on leaf page even if it is deleted page. But replica reinitializes page during replay of page deletion, causing deleted page to have no items. Thus, replay of page deletion can cause an error in concurrent amcheck run. This commit relaxes amcheck expectation making it tolerate deleted page with no items. Reported-by: Konstantin Knizhnik Discussion: https://postgr.es/m/CAPpHfdt_OTyQpXaPJcWzV2N-LNeNJseNB-K_A66qG%3DL518VTFw%40mail.gmail.com Author: Alexander Korotkov Reviewed-by: Peter Geoghegan Backpatch-through: 11 --- contrib/amcheck/verify_nbtree.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/contrib/amcheck/verify_nbtree.c b/contrib/amcheck/verify_nbtree.c index 05e7d678ed..700a02ffe4 100644 --- a/contrib/amcheck/verify_nbtree.c +++ b/contrib/amcheck/verify_nbtree.c @@ -2416,7 +2416,11 @@ palloc_btree_page(BtreeCheckState *state, BlockNumber blocknum) * As noted at the beginning of _bt_binsrch(), an internal page must have * children, since there must always be a negative infinity downlink * (there may also be a highkey). In the case of non-rightmost leaf - * pages, there must be at least a highkey. + * pages, there must be at least a highkey. Deleted pages on replica + * might contain no items, because page unlink re-initializes + * page-to-be-deleted. Deleted pages with no items might be on primary + * too due to preceding recovery, but on primary new deletions can't + * happen concurrently to amcheck. * * This is correct when pages are half-dead, since internal pages are * never half-dead, and leaf pages must have a high key when half-dead @@ -2436,13 +2440,13 @@ palloc_btree_page(BtreeCheckState *state, BlockNumber blocknum) blocknum, RelationGetRelationName(state->rel), MaxIndexTuplesPerPage))); - if (!P_ISLEAF(opaque) && maxoffset < P_FIRSTDATAKEY(opaque)) + if (!P_ISLEAF(opaque) && !P_ISDELETED(opaque) && maxoffset < P_FIRSTDATAKEY(opaque)) ereport(ERROR, (errcode(ERRCODE_INDEX_CORRUPTED), errmsg("internal block %u in index \"%s\" lacks high key and/or at least one downlink", blocknum, RelationGetRelationName(state->rel)))); - if (P_ISLEAF(opaque) && !P_RIGHTMOST(opaque) && maxoffset < P_HIKEY) + if (P_ISLEAF(opaque) && !P_ISDELETED(opaque) && !P_RIGHTMOST(opaque) && maxoffset < P_HIKEY) ereport(ERROR, (errcode(ERRCODE_INDEX_CORRUPTED), errmsg("non-rightmost leaf block %u in index \"%s\" lacks high key item",