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.

1 files changed, 7 insertions, 4 deletions

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);