Rethink the way FSM truncation works. Instead of WAL-logging FSM

truncations in FSM code, call FreeSpaceMapTruncateRel from smgr_redo. To
make that cleaner from modularity point of view, move the WAL-logging one
level up to RelationTruncate, and move RelationTruncate and all the
related WAL-logging to new src/backend/catalog/storage.c file. Introduce
new RelationCreateStorage and RelationDropStorage functions that are used
instead of calling smgrcreate/smgrscheduleunlink directly. Move the
pending rel deletion stuff from smgrcreate/smgrscheduleunlink to the new
functions. This leaves smgr.c as a thin wrapper around md.c; all the
transactional stuff is now in storage.c.

This will make it easier to add new forks with similar truncation logic,
like the visibility map.

1 files changed, 1 insertions, 27 deletions

diff --git a/src/backend/storage/freespace/indexfsm.c b/src/backend/storage/freespace/indexfsm.c
index 768b633f081..58d8e6caf2e 100644
--- a/src/backend/storage/freespace/indexfsm.c
+++ b/src/backend/storage/freespace/indexfsm.c
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/freespace/indexfsm.c,v 1.2 2008/10/06 08:04:11 heikki Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/freespace/indexfsm.c,v 1.3 2008/11/19 10:34:52 heikki Exp $
  *
  *
  * NOTES:
@@ -31,20 +31,6 @@
  */
 
 /*
- * InitIndexFreeSpaceMap - Create or reset the FSM fork for relation.
- */
-void
-InitIndexFreeSpaceMap(Relation rel)
-{
-	/* Create FSM fork if it doesn't exist yet, or truncate it if it does */
-	RelationOpenSmgr(rel);
-	if (!smgrexists(rel->rd_smgr, FSM_FORKNUM))
-		smgrcreate(rel->rd_smgr, FSM_FORKNUM, rel->rd_istemp, false);
-	else
-		smgrtruncate(rel->rd_smgr, FSM_FORKNUM, 0, rel->rd_istemp);
-}
-
-/*
  * GetFreeIndexPage - return a free page from the FSM
  *
  * As a side effect, the page is marked as used in the FSM.
@@ -80,18 +66,6 @@ RecordUsedIndexPage(Relation rel, BlockNumber usedBlock)
 }
 
 /*
- * IndexFreeSpaceMapTruncate - adjust for truncation of a relation.
- *
- * We need to delete any stored data past the new relation length, so that
- * we don't bogusly return removed block numbers.
- */
-void
-IndexFreeSpaceMapTruncate(Relation rel, BlockNumber nblocks)
-{
-	FreeSpaceMapTruncateRel(rel, nblocks);
-}
-
-/*
  * IndexFreeSpaceMapVacuum - scan and fix any inconsistencies in the FSM
  */
 void