Fix checksums for CLUSTER, VACUUM FULL etc.

In CLUSTER, VACUUM FULL and ALTER TABLE SET TABLESPACE
I erroneously set checksum before log_newpage, which
sets the LSN and invalidates the checksum. So set
checksum immediately *after* log_newpage.

Bug report Fujii Masao, Fix and patch by Jeff Davis

(cherry picked from commit cf8dc9e1)

src/backend/access/heap/rewriteheap.c

@@ -266,12 +266,13 @@ end_heap_rewrite(RewriteState state)
 	/* Write the last page, if any */
 	if (state->rs_buffer_valid)
 	{
-		PageSetChecksumInplace(state->rs_buffer, state->rs_blockno);
-
 		if (state->rs_use_wal)
 			log_newpage_rel(state->rs_new_rel,state->rs_blockno, state->rs_buffer);
 
 		RelationOpenSmgr(state->rs_new_rel);
+
+		PageSetChecksumInplace(state->rs_buffer, state->rs_blockno);
+
 		smgrextend(state->rs_new_rel->rd_smgr, state->rs_blockno,
 				   (char *) state->rs_buffer, true);
 	}
@@ -603,8 +604,6 @@ raw_heap_insert(RewriteState state, HeapTuple tup)
 		{
 			/* Doesn't fit, so write out the existing page */
 
-			PageSetChecksumInplace(page, state->rs_blockno);
-
 			/* XLOG stuff */
 			if (state->rs_use_wal)
 				log_newpage_rel(state->rs_new_rel, state->rs_blockno, page);
@@ -616,6 +615,9 @@ raw_heap_insert(RewriteState state, HeapTuple tup)
 			 * end_heap_rewrite.
 			 */
 			RelationOpenSmgr(state->rs_new_rel);
+
+			PageSetChecksumInplace(page, state->rs_blockno);
+
 			smgrextend(state->rs_new_rel->rd_smgr, state->rs_blockno,
 					   (char *) page, true);
 

src/backend/commands/tablecmds.c

@@ -10272,7 +10272,14 @@ copy_buffer_pool_data(Relation rel, SMgrRelation dst,
 
 		smgrread(src, blkno, buf);
 
-		PageSetChecksumInplace(page, blkno);
+		if (!PageIsVerified(page, blkno))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATA_CORRUPTED),
+					 errmsg("invalid page in block %u of relation %s/%s/%s",
+							blkno,
+							src->smgr_rnode.spcNode,
+							src->smgr_rnode.dbNode,
+							src->smgr_rnode.relNode)));
 
 		/* XLOG stuff */
 		if (useWal)
@@ -10281,6 +10288,8 @@ copy_buffer_pool_data(Relation rel, SMgrRelation dst,
 						persistentSerialNum);
 		}
 
+		PageSetChecksumInplace(page, blkno);
+
 		// -------- MirroredLock ----------
 		LWLockAcquire(MirroredLock, LW_SHARED);