From 017e78a3edc261143c7d791cafca5a5ad326a679 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Mon, 2 Nov 2020 10:41:23 +0900 Subject: [PATCH] Extend PageIsVerified() to handle more custom options This is useful for checks of relation pages without having to load the pages into the shared buffers, and two cases can make use of that: page verification in base backups and the online, lock-safe, flavor. Compatibility is kept with past versions using a routine that calls the new extended routine with the set of options compatible with the original version. Contrary to d401c576, a macro cannot be used as there may be external code relying on the presence of the original routine. This is applied down to 11, where this will be used by a follow-up commit addressing a set of issues with page verification in base backups. Extracted from a larger patch by the same author. Author: Anastasia Lubennikova Reviewed-by: Michael Paquier, Julien Rouhaud Discussion: https://postgr.es/m/608f3476-0598-2514-2c03-e05c7d2b0cbd@postgrespro.ru Backpatch-through: 11 --- src/backend/catalog/storage.c | 3 ++- src/backend/storage/buffer/bufmgr.c | 6 ++++-- src/backend/storage/page/bufpage.c | 32 +++++++++++++++++++++++------ src/include/storage/bufpage.h | 17 ++++++++++----- 4 files changed, 44 insertions(+), 14 deletions(-) diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c index ec143b640a..74216785b7 100644 --- a/src/backend/catalog/storage.c +++ b/src/backend/catalog/storage.c @@ -443,7 +443,8 @@ RelationCopyStorage(SMgrRelation src, SMgrRelation dst, smgrread(src, forkNum, blkno, buf.data); - if (!PageIsVerified(page, blkno)) + if (!PageIsVerifiedExtended(page, blkno, + PIV_LOG_WARNING | PIV_REPORT_STAT)) ereport(ERROR, (errcode(ERRCODE_DATA_CORRUPTED), errmsg("invalid page in block %u of relation %s", diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c index 29c920800a..9381f9981d 100644 --- a/src/backend/storage/buffer/bufmgr.c +++ b/src/backend/storage/buffer/bufmgr.c @@ -624,7 +624,8 @@ ReadBuffer(Relation reln, BlockNumber blockNum) * * In RBM_NORMAL mode, the page is read from disk, and the page header is * validated. An error is thrown if the page header is not valid. (But - * note that an all-zero page is considered "valid"; see PageIsVerified().) + * note that an all-zero page is considered "valid"; see + * PageIsVerifiedExtended().) * * RBM_ZERO_ON_ERROR is like the normal mode, but if the page header is not * valid, the page is zeroed instead of throwing an error. This is intended @@ -916,7 +917,8 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum, } /* check for garbage data */ - if (!PageIsVerified((Page) bufBlock, blockNum)) + if (!PageIsVerifiedExtended((Page) bufBlock, blockNum, + PIV_LOG_WARNING | PIV_REPORT_STAT)) { if (mode == RBM_ZERO_ON_ERROR || zero_damaged_pages) { diff --git a/src/backend/storage/page/bufpage.c b/src/backend/storage/page/bufpage.c index d708117a40..8dc67c97cb 100644 --- a/src/backend/storage/page/bufpage.c +++ b/src/backend/storage/page/bufpage.c @@ -62,6 +62,18 @@ PageInit(Page page, Size pageSize, Size specialSize) /* * PageIsVerified + * Utility wrapper for PageIsVerifiedExtended(). + */ +bool +PageIsVerified(Page page, BlockNumber blkno) +{ + return PageIsVerifiedExtended(page, blkno, + PIV_LOG_WARNING | PIV_REPORT_STAT); +} + + +/* + * PageIsVerifiedExtended * Check that the page header and checksum (if any) appear valid. * * This is called when a page has just been read in from disk. The idea is @@ -77,9 +89,15 @@ PageInit(Page page, Size pageSize, Size specialSize) * allow zeroed pages here, and are careful that the page access macros * treat such a page as empty and without free space. Eventually, VACUUM * will clean up such a page and make it usable. + * + * If flag PIV_LOG_WARNING is set, a WARNING is logged in the event of + * a checksum failure. + * + * If flag PIV_REPORT_STAT is set, a checksum failure is reported directly + * to pgstat. */ bool -PageIsVerified(Page page, BlockNumber blkno) +PageIsVerifiedExtended(Page page, BlockNumber blkno, int flags) { PageHeader p = (PageHeader) page; size_t *pagebytes; @@ -140,12 +158,14 @@ PageIsVerified(Page page, BlockNumber blkno) */ if (checksum_failure) { - ereport(WARNING, - (errcode(ERRCODE_DATA_CORRUPTED), - errmsg("page verification failed, calculated checksum %u but expected %u", - checksum, p->pd_checksum))); + if ((flags & PIV_LOG_WARNING) != 0) + ereport(WARNING, + (errcode(ERRCODE_DATA_CORRUPTED), + errmsg("page verification failed, calculated checksum %u but expected %u", + checksum, p->pd_checksum))); - pgstat_report_checksum_failure(); + if ((flags & PIV_REPORT_STAT) != 0) + pgstat_report_checksum_failure(); if (header_sane && ignore_checksum_failure) return true; diff --git a/src/include/storage/bufpage.h b/src/include/storage/bufpage.h index 3f88683a05..4d0ae4b36b 100644 --- a/src/include/storage/bufpage.h +++ b/src/include/storage/bufpage.h @@ -410,26 +410,33 @@ do { \ * extern declarations * ---------------------------------------------------------------- */ + +/* flags for PageAddItemExtended() */ #define PAI_OVERWRITE (1 << 0) #define PAI_IS_HEAP (1 << 1) +/* flags for PageIsVerifiedExtended() */ +#define PIV_LOG_WARNING (1 << 0) +#define PIV_REPORT_STAT (1 << 1) + #define PageAddItem(page, item, size, offsetNumber, overwrite, is_heap) \ PageAddItemExtended(page, item, size, offsetNumber, \ ((overwrite) ? PAI_OVERWRITE : 0) | \ ((is_heap) ? PAI_IS_HEAP : 0)) /* - * Check that BLCKSZ is a multiple of sizeof(size_t). In PageIsVerified(), - * it is much faster to check if a page is full of zeroes using the native - * word size. Note that this assertion is kept within a header to make - * sure that StaticAssertDecl() works across various combinations of - * platforms and compilers. + * Check that BLCKSZ is a multiple of sizeof(size_t). In + * PageIsVerifiedExtended(), it is much faster to check if a page is + * full of zeroes using the native word size. Note that this assertion + * is kept within a header to make sure that StaticAssertDecl() works + * across various combinations of platforms and compilers. */ StaticAssertDecl(BLCKSZ == ((BLCKSZ / sizeof(size_t)) * sizeof(size_t)), "BLCKSZ has to be a multiple of sizeof(size_t)"); extern void PageInit(Page page, Size pageSize, Size specialSize); extern bool PageIsVerified(Page page, BlockNumber blkno); +extern bool PageIsVerifiedExtended(Page page, BlockNumber blkno, int flags); extern OffsetNumber PageAddItemExtended(Page page, Item item, Size size, OffsetNumber offsetNumber, int flags); extern Page PageGetTempPage(Page page);