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 macro that calls the
new extended routine with the set of options compatible with the
original version.

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

diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index dbbd3aa31fe14281ba5d4fedf0d777be1022116e..d538f25726f4584c11a2e23b6328b19d6c25cb46 100644 (file)
--- 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 e549fa1d309fe5021e58877bbd21f80f9c0070d5..3eee86afe5c4748a3e3176cbf8e23d7a341b4b7e 100644 (file)
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -625,7 +625,8 @@ 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
@@ -917,7 +918,8 @@ 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 4bc2bf955dfd5aa1d4b2c4f0dc606b442da57d34..ddf18079e2fbf714ae795a0c9beaddda9ed76c93 100644 (file)
--- a/src/backend/storage/page/bufpage.c
+++ b/src/backend/storage/page/bufpage.c
@@ -61,7 +61,7 @@ PageInit(Page page, Size pageSize, Size specialSize)
 
 
 /*
- * PageIsVerified
+ * 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 +77,15 @@ 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 +146,14 @@ 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 51b8f994ac0ae973eb1e9f726e240005722fc3a9..d0a52f8e08fc926f5a061a12f87e08c8d197760c 100644 (file)
--- a/src/include/storage/bufpage.h
+++ b/src/include/storage/bufpage.h
@@ -404,26 +404,36 @@ 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))
 
+#define PageIsVerified(page, blkno) \
+       PageIsVerifiedExtended(page, blkno, \
+                                                  PIV_LOG_WARNING | PIV_REPORT_STAT)
+
 /*
- * 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);