For wal_consistency_checking, mask page checksum as well as page LSN.

If the LSN is different, the checksum will be different, too.

Ashwin Agrawal, reviewed by Michael Paquier and Kuntal Ghosh

Discussion: http://postgr.es/m/CALfoeis5iqrAU-+JAN+ZzXkpPr7+-0OAGv7QUHwFn=-wDy4o4Q@mail.gmail.com

11 files changed, 16 insertions, 14 deletions

diff --git a/src/backend/access/brin/brin_xlog.c b/src/backend/access/brin/brin_xlog.c
index dff7198a39e..60daa54a95b 100644
--- a/src/backend/access/brin/brin_xlog.c
+++ b/src/backend/access/brin/brin_xlog.c
@@ -332,7 +332,7 @@ brin_mask(char *pagedata, BlockNumber blkno)
 {
 	Page		page = (Page) pagedata;
 
-	mask_page_lsn(page);
+	mask_page_lsn_and_checksum(page);
 
 	mask_page_hint_bits(page);
 
diff --git a/src/backend/access/common/bufmask.c b/src/backend/access/common/bufmask.c
index 10253d33545..d880aef7bad 100644
--- a/src/backend/access/common/bufmask.c
+++ b/src/backend/access/common/bufmask.c
@@ -23,15 +23,17 @@
  * mask_page_lsn
  *
  * In consistency checks, the LSN of the two pages compared will likely be
- * different because of concurrent operations when the WAL is generated
- * and the state of the page when WAL is applied.
+ * different because of concurrent operations when the WAL is generated and
+ * the state of the page when WAL is applied. Also, mask out checksum as
+ * masking anything else on page means checksum is not going to match as well.
  */
 void
-mask_page_lsn(Page page)
+mask_page_lsn_and_checksum(Page page)
 {
 	PageHeader	phdr = (PageHeader) page;
 
 	PageXLogRecPtrSet(phdr->pd_lsn, (uint64) MASK_MARKER);
+	phdr->pd_checksum = MASK_MARKER;
 }
 
 /*
diff --git a/src/backend/access/gin/ginxlog.c b/src/backend/access/gin/ginxlog.c
index 7ba04e324f6..92cafe950b6 100644
--- a/src/backend/access/gin/ginxlog.c
+++ b/src/backend/access/gin/ginxlog.c
@@ -770,7 +770,7 @@ gin_mask(char *pagedata, BlockNumber blkno)
 	Page		page = (Page) pagedata;
 	GinPageOpaque opaque;
 
-	mask_page_lsn(page);
+	mask_page_lsn_and_checksum(page);
 	opaque = GinPageGetOpaque(page);
 
 	mask_page_hint_bits(page);
diff --git a/src/backend/access/gist/gistxlog.c b/src/backend/access/gist/gistxlog.c
index 4f4fe8fab53..7fd91ce640a 100644
--- a/src/backend/access/gist/gistxlog.c
+++ b/src/backend/access/gist/gistxlog.c
@@ -352,14 +352,14 @@ gist_mask(char *pagedata, BlockNumber blkno)
 {
 	Page		page = (Page) pagedata;
 
-	mask_page_lsn(page);
+	mask_page_lsn_and_checksum(page);
 
 	mask_page_hint_bits(page);
 	mask_unused_space(page);
 
 	/*
 	 * NSN is nothing but a special purpose LSN. Hence, mask it for the same
-	 * reason as mask_page_lsn.
+	 * reason as mask_page_lsn_and_checksum.
 	 */
 	GistPageSetNSN(page, (uint64) MASK_MARKER);
 
diff --git a/src/backend/access/hash/hash_xlog.c b/src/backend/access/hash/hash_xlog.c
index 67a856c1427..f19f6fdfafa 100644
--- a/src/backend/access/hash/hash_xlog.c
+++ b/src/backend/access/hash/hash_xlog.c
@@ -1263,7 +1263,7 @@ hash_mask(char *pagedata, BlockNumber blkno)
 	HashPageOpaque opaque;
 	int			pagetype;
 
-	mask_page_lsn(page);
+	mask_page_lsn_and_checksum(page);
 
 	mask_page_hint_bits(page);
 	mask_unused_space(page);
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index e61dd771d0c..2d321171fad 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -9149,7 +9149,7 @@ heap_mask(char *pagedata, BlockNumber blkno)
 	Page		page = (Page) pagedata;
 	OffsetNumber off;
 
-	mask_page_lsn(page);
+	mask_page_lsn_and_checksum(page);
 
 	mask_page_hint_bits(page);
 	mask_unused_space(page);
diff --git a/src/backend/access/nbtree/nbtxlog.c b/src/backend/access/nbtree/nbtxlog.c
index ac60db0d490..d67241c2832 100644
--- a/src/backend/access/nbtree/nbtxlog.c
+++ b/src/backend/access/nbtree/nbtxlog.c
@@ -1040,7 +1040,7 @@ btree_mask(char *pagedata, BlockNumber blkno)
 	Page		page = (Page) pagedata;
 	BTPageOpaque maskopaq;
 
-	mask_page_lsn(page);
+	mask_page_lsn_and_checksum(page);
 
 	mask_page_hint_bits(page);
 	mask_unused_space(page);
diff --git a/src/backend/access/spgist/spgxlog.c b/src/backend/access/spgist/spgxlog.c
index c440d217159..87def79ee5d 100644
--- a/src/backend/access/spgist/spgxlog.c
+++ b/src/backend/access/spgist/spgxlog.c
@@ -1034,7 +1034,7 @@ spg_mask(char *pagedata, BlockNumber blkno)
 {
 	Page		page = (Page) pagedata;
 
-	mask_page_lsn(page);
+	mask_page_lsn_and_checksum(page);
 
 	mask_page_hint_bits(page);
 
diff --git a/src/backend/access/transam/generic_xlog.c b/src/backend/access/transam/generic_xlog.c
index fbc6810c2f2..3adbf7b9494 100644
--- a/src/backend/access/transam/generic_xlog.c
+++ b/src/backend/access/transam/generic_xlog.c
@@ -541,7 +541,7 @@ generic_redo(XLogReaderState *record)
 void
 generic_mask(char *page, BlockNumber blkno)
 {
-	mask_page_lsn(page);
+	mask_page_lsn_and_checksum(page);
 
 	mask_unused_space(page);
 }
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 62937124efe..5c2ce789468 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -1941,7 +1941,7 @@ ResetSequenceCaches(void)
 void
 seq_mask(char *page, BlockNumber blkno)
 {
-	mask_page_lsn(page);
+	mask_page_lsn_and_checksum(page);
 
 	mask_unused_space(page);
 }
diff --git a/src/include/access/bufmask.h b/src/include/access/bufmask.h
index 95c6c3ae020..6a24c947efc 100644
--- a/src/include/access/bufmask.h
+++ b/src/include/access/bufmask.h
@@ -23,7 +23,7 @@
 /* Marker used to mask pages consistently */
 #define MASK_MARKER		0
 
-extern void mask_page_lsn(Page page);
+extern void mask_page_lsn_and_checksum(Page page);
 extern void mask_page_hint_bits(Page page);
 extern void mask_unused_space(Page page);
 extern void mask_lp_flags(Page page);