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

3 files changed, 21 insertions, 10 deletions

diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index dbbd3aa31fe..d538f25726f 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 e549fa1d309..3eee86afe5c 100644
--- 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 4bc2bf955df..ddf18079e2f 100644
--- 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;