Unite ReadBufferWithFork, ReadBufferWithStrategy, and ZeroOrReadBuffer

functions into one ReadBufferExtended function, that takes the strategy
and mode as argument. There's three modes, RBM_NORMAL which is the default
used by plain ReadBuffer(), RBM_ZERO, which replaces ZeroOrReadBuffer, and
a new mode RBM_ZERO_ON_ERROR, which allows callers to read corrupt pages
without throwing an error. The FSM needs the new mode to recover from
corrupt pages, which could happend if we crash after extending an FSM file,
and the new page is "torn".

Add fork number to some error messages in bufmgr.c, that still lacked it.

3 files changed, 35 insertions, 29 deletions

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index c207e502ee8..4b164aa7c5f 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/analyze.c,v 1.125 2008/08/25 22:42:32 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/analyze.c,v 1.126 2008/10/31 15:05:00 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -911,7 +911,8 @@ acquire_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
 		 * each tuple, but since we aren't doing much work per tuple, the
 		 * extra lock traffic is probably better avoided.
 		 */
-		targbuffer = ReadBufferWithStrategy(onerel, targblock, vac_strategy);
+		targbuffer = ReadBufferExtended(onerel, MAIN_FORKNUM, targblock,
+										RBM_NORMAL, vac_strategy);
 		LockBuffer(targbuffer, BUFFER_LOCK_SHARE);
 		targpage = BufferGetPage(targbuffer);
 		maxoffset = PageGetMaxOffsetNumber(targpage);
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 925a8d8abd3..14ed83d1d30 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.378 2008/09/30 10:52:12 heikki Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.379 2008/10/31 15:05:00 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1348,7 +1348,8 @@ scan_heap(VRelStats *vacrelstats, Relation onerel,
 
 		vacuum_delay_point();
 
-		buf = ReadBufferWithStrategy(onerel, blkno, vac_strategy);
+		buf = ReadBufferExtended(onerel, MAIN_FORKNUM, blkno, RBM_NORMAL,
+								 vac_strategy);
 		page = BufferGetPage(buf);
 
 		/*
@@ -1919,7 +1920,8 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 		/*
 		 * Process this page of relation.
 		 */
-		buf = ReadBufferWithStrategy(onerel, blkno, vac_strategy);
+		buf = ReadBufferExtended(onerel, MAIN_FORKNUM, blkno, RBM_NORMAL,
+								 vac_strategy);
 		page = BufferGetPage(buf);
 
 		vacpage->offsets_free = 0;
@@ -2173,9 +2175,9 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 					nextTid = tp.t_data->t_ctid;
 					priorXmax = HeapTupleHeaderGetXmax(tp.t_data);
 					/* assume block# is OK (see heap_fetch comments) */
-					nextBuf = ReadBufferWithStrategy(onerel,
+					nextBuf = ReadBufferExtended(onerel, MAIN_FORKNUM,
 										 ItemPointerGetBlockNumber(&nextTid),
-													 vac_strategy);
+										 RBM_NORMAL, vac_strategy);
 					nextPage = BufferGetPage(nextBuf);
 					/* If bogus or unused slot, assume tp is end of chain */
 					nextOffnum = ItemPointerGetOffsetNumber(&nextTid);
@@ -2318,9 +2320,9 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 						break;	/* out of check-all-items loop */
 					}
 					tp.t_self = vtlp->this_tid;
-					Pbuf = ReadBufferWithStrategy(onerel,
+					Pbuf = ReadBufferExtended(onerel, MAIN_FORKNUM,
 									 ItemPointerGetBlockNumber(&(tp.t_self)),
-												  vac_strategy);
+									 RBM_NORMAL, vac_strategy);
 					Ppage = BufferGetPage(Pbuf);
 					Pitemid = PageGetItemId(Ppage,
 								   ItemPointerGetOffsetNumber(&(tp.t_self)));
@@ -2402,14 +2404,14 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 
 					/* Get page to move from */
 					tuple.t_self = vtmove[ti].tid;
-					Cbuf = ReadBufferWithStrategy(onerel,
+					Cbuf = ReadBufferExtended(onerel, MAIN_FORKNUM,
 								  ItemPointerGetBlockNumber(&(tuple.t_self)),
-												  vac_strategy);
+								  RBM_NORMAL, vac_strategy);
 
 					/* Get page to move to */
-					dst_buffer = ReadBufferWithStrategy(onerel,
-														destvacpage->blkno,
-														vac_strategy);
+					dst_buffer = ReadBufferExtended(onerel, MAIN_FORKNUM,
+													destvacpage->blkno,
+													RBM_NORMAL, vac_strategy);
 
 					LockBuffer(dst_buffer, BUFFER_LOCK_EXCLUSIVE);
 					if (dst_buffer != Cbuf)
@@ -2502,9 +2504,9 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 				if (i == num_fraged_pages)
 					break;		/* can't move item anywhere */
 				dst_vacpage = fraged_pages->pagedesc[i];
-				dst_buffer = ReadBufferWithStrategy(onerel,
-													dst_vacpage->blkno,
-													vac_strategy);
+				dst_buffer = ReadBufferExtended(onerel, MAIN_FORKNUM,
+												dst_vacpage->blkno,
+												RBM_NORMAL, vac_strategy);
 				LockBuffer(dst_buffer, BUFFER_LOCK_EXCLUSIVE);
 				dst_page = BufferGetPage(dst_buffer);
 				/* if this page was not used before - clean it */
@@ -2681,9 +2683,8 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 			Page		page;
 
 			/* this page was not used as a move target, so must clean it */
-			buf = ReadBufferWithStrategy(onerel,
-										 (*curpage)->blkno,
-										 vac_strategy);
+			buf = ReadBufferExtended(onerel, MAIN_FORKNUM, (*curpage)->blkno,
+									 RBM_NORMAL, vac_strategy);
 			LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 			page = BufferGetPage(buf);
 			if (!PageIsEmpty(page))
@@ -2770,7 +2771,8 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 			int			uncnt = 0;
 			int			num_tuples = 0;
 
-			buf = ReadBufferWithStrategy(onerel, vacpage->blkno, vac_strategy);
+			buf = ReadBufferExtended(onerel, MAIN_FORKNUM, vacpage->blkno,
+									 RBM_NORMAL, vac_strategy);
 			LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 			page = BufferGetPage(buf);
 			maxoff = PageGetMaxOffsetNumber(page);
@@ -3150,7 +3152,8 @@ update_hint_bits(Relation rel, VacPageList fraged_pages, int num_fraged_pages,
 			break;				/* no need to scan any further */
 		if ((*curpage)->offsets_used == 0)
 			continue;			/* this page was never used as a move dest */
-		buf = ReadBufferWithStrategy(rel, (*curpage)->blkno, vac_strategy);
+		buf = ReadBufferExtended(rel, MAIN_FORKNUM, (*curpage)->blkno,
+								 RBM_NORMAL, vac_strategy);
 		LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 		page = BufferGetPage(buf);
 		max_offset = PageGetMaxOffsetNumber(page);
@@ -3219,9 +3222,8 @@ vacuum_heap(VRelStats *vacrelstats, Relation onerel, VacPageList vacuum_pages)
 
 		if ((*vacpage)->offsets_free > 0)
 		{
-			buf = ReadBufferWithStrategy(onerel,
-										 (*vacpage)->blkno,
-										 vac_strategy);
+			buf = ReadBufferExtended(onerel, MAIN_FORKNUM, (*vacpage)->blkno,
+									 RBM_NORMAL, vac_strategy);
 			LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 			vacuum_page(onerel, buf, *vacpage);
 			UnlockReleaseBuffer(buf);
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index fbaeb8d602a..48be3f411af 100644
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -29,7 +29,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.108 2008/09/30 10:52:12 heikki Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.109 2008/10/31 15:05:00 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -301,7 +301,8 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
 			vacrelstats->num_index_scans++;
 		}
 
-		buf = ReadBufferWithStrategy(onerel, blkno, vac_strategy);
+		buf = ReadBufferExtended(onerel, MAIN_FORKNUM, blkno,
+								 RBM_NORMAL, vac_strategy);
 
 		/* We need buffer cleanup lock so that we can prune HOT chains. */
 		LockBufferForCleanup(buf);
@@ -618,7 +619,8 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
 		vacuum_delay_point();
 
 		tblk = ItemPointerGetBlockNumber(&vacrelstats->dead_tuples[tupindex]);
-		buf = ReadBufferWithStrategy(onerel, tblk, vac_strategy);
+		buf = ReadBufferExtended(onerel, MAIN_FORKNUM, tblk, RBM_NORMAL,
+								 vac_strategy);
 		LockBufferForCleanup(buf);
 		tupindex = lazy_vacuum_page(onerel, tblk, buf, tupindex, vacrelstats);
 
@@ -880,7 +882,8 @@ count_nondeletable_pages(Relation onerel, LVRelStats *vacrelstats)
 
 		blkno--;
 
-		buf = ReadBufferWithStrategy(onerel, blkno, vac_strategy);
+		buf = ReadBufferExtended(onerel, MAIN_FORKNUM, blkno,
+								 RBM_NORMAL, vac_strategy);
 
 		/* In this phase we only need shared access to the buffer */
 		LockBuffer(buf, BUFFER_LOCK_SHARE);