Revert no-op changes to BufferGetPage()

The reverted changes were intended to force a choice of whether any
newly-added BufferGetPage() calls needed to be accompanied by a
test of the snapshot age, to support the "snapshot too old"
feature.  Such an accompanying test is needed in about 7% of the
cases, where the page is being used as part of a scan rather than
positioning for other purposes (such as DML or vacuuming).  The
additional effort required for back-patching, and the doubt whether
the intended benefit would really be there, have indicated it is
best just to rely on developers to do the right thing based on
comments and existing usage, as we do with many other conventions.

This change should have little or no effect on generated executable
code.

Motivated by the back-patching pain of Tom Lane and Robert Haas

1 files changed, 12 insertions, 17 deletions

diff --git a/src/backend/access/gin/ginvacuum.c b/src/backend/access/gin/ginvacuum.c
index f26dc799b5d..6a4b98a4e7e 100644
--- a/src/backend/access/gin/ginvacuum.c
+++ b/src/backend/access/gin/ginvacuum.c
@@ -87,8 +87,7 @@ ginVacuumItemPointers(GinVacuumState *gvs, ItemPointerData *items,
 static void
 xlogVacuumPage(Relation index, Buffer buffer)
 {
-	Page		page = BufferGetPage(buffer, NULL, NULL,
-									 BGP_NO_SNAPSHOT_TEST);
+	Page		page = BufferGetPage(buffer);
 	XLogRecPtr	recptr;
 
 	/* This is only used for entry tree leaf pages. */
@@ -119,7 +118,7 @@ ginVacuumPostingTreeLeaves(GinVacuumState *gvs, BlockNumber blkno, bool isRoot,
 
 	buffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, blkno,
 								RBM_NORMAL, gvs->strategy);
-	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = BufferGetPage(buffer);
 
 	/*
 	 * We should be sure that we don't concurrent with inserts, insert process
@@ -213,14 +212,14 @@ ginDeletePage(GinVacuumState *gvs, BlockNumber deleteBlkno, BlockNumber leftBlkn
 	START_CRIT_SECTION();
 
 	/* Unlink the page by changing left sibling's rightlink */
-	page = BufferGetPage(dBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = BufferGetPage(dBuffer);
 	rightlink = GinPageGetOpaque(page)->rightlink;
 
-	page = BufferGetPage(lBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = BufferGetPage(lBuffer);
 	GinPageGetOpaque(page)->rightlink = rightlink;
 
 	/* Delete downlink from parent */
-	parentPage = BufferGetPage(pBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	parentPage = BufferGetPage(pBuffer);
 #ifdef USE_ASSERT_CHECKING
 	do
 	{
@@ -231,7 +230,7 @@ ginDeletePage(GinVacuumState *gvs, BlockNumber deleteBlkno, BlockNumber leftBlkn
 #endif
 	GinPageDeletePostingItem(parentPage, myoff);
 
-	page = BufferGetPage(dBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = BufferGetPage(dBuffer);
 
 	/*
 	 * we shouldn't change rightlink field to save workability of running
@@ -269,8 +268,7 @@ ginDeletePage(GinVacuumState *gvs, BlockNumber deleteBlkno, BlockNumber leftBlkn
 		recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_DELETE_PAGE);
 		PageSetLSN(page, recptr);
 		PageSetLSN(parentPage, recptr);
-		PageSetLSN(BufferGetPage(lBuffer, NULL, NULL,
-								 BGP_NO_SNAPSHOT_TEST), recptr);
+		PageSetLSN(BufferGetPage(lBuffer), recptr);
 	}
 
 	if (!isParentRoot)
@@ -326,7 +324,7 @@ ginScanToDelete(GinVacuumState *gvs, BlockNumber blkno, bool isRoot,
 
 	buffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, blkno,
 								RBM_NORMAL, gvs->strategy);
-	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = BufferGetPage(buffer);
 
 	Assert(GinPageIsData(page));
 
@@ -409,8 +407,7 @@ ginVacuumPostingTree(GinVacuumState *gvs, BlockNumber rootBlkno)
 static Page
 ginVacuumEntryPage(GinVacuumState *gvs, Buffer buffer, BlockNumber *roots, uint32 *nroot)
 {
-	Page		origpage = BufferGetPage(buffer, NULL, NULL,
-										 BGP_NO_SNAPSHOT_TEST),
+	Page		origpage = BufferGetPage(buffer),
 				tmppage;
 	OffsetNumber i,
 				maxoff = PageGetMaxOffsetNumber(origpage);
@@ -557,8 +554,7 @@ ginbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 	/* find leaf page */
 	for (;;)
 	{
-		Page		page = BufferGetPage(buffer, NULL, NULL,
-										 BGP_NO_SNAPSHOT_TEST);
+		Page		page = BufferGetPage(buffer);
 		IndexTuple	itup;
 
 		LockBuffer(buffer, GIN_SHARE);
@@ -593,8 +589,7 @@ ginbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 
 	for (;;)
 	{
-		Page		page = BufferGetPage(buffer, NULL, NULL,
-										 BGP_NO_SNAPSHOT_TEST);
+		Page		page = BufferGetPage(buffer);
 		Page		resPage;
 		uint32		i;
 
@@ -708,7 +703,7 @@ ginvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
 		buffer = ReadBufferExtended(index, MAIN_FORKNUM, blkno,
 									RBM_NORMAL, info->strategy);
 		LockBuffer(buffer, GIN_SHARE);
-		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		page = (Page) BufferGetPage(buffer);
 
 		if (PageIsNew(page) || GinPageIsDeleted(page))
 		{