[XFS] Add parameters to xfs_bmapi() and xfs_bunmapi() to have them report

the range spanned by modifications to the in-core extent map.  Add
XFS_BUNMAPI() and XFS_SWAP_EXTENTS() macros that call xfs_bunmapi() and
xfs_swap_extents() via the ioops vector. Change all calls that may modify
the in-core extent map for the data fork to go through the ioops vector. 
This allows a cache of extent map data to be kept in sync.

SGI-PV: 947615
SGI-Modid: xfs-linux-melb:xfs-kern:209226a

Signed-off-by: Olaf Weber <olaf@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

fs/xfs/xfs_bmap.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
  * All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or
@@ -25,6 +25,20 @@ struct xfs_inode;
 struct xfs_mount;
 struct xfs_trans;
 
+/*
+ * DELTA: describe a change to the in-core extent list.
+ *
+ * Internally the use of xed_blockount is somewhat funky.
+ * xed_blockcount contains an offset much of the time because this
+ * makes merging changes easier.  (xfs_fileoff_t and xfs_filblks_t are
+ * the same underlying type).
+ */
+typedef struct xfs_extdelta
+{
+	xfs_fileoff_t		xed_startoff;	/* offset of range */
+	xfs_filblks_t		xed_blockcount;	/* blocks in range */
+} xfs_extdelta_t;
+
 /*
  * List of extents to be free "later".
  * The list is kept sorted on xbf_startblock.
@@ -275,7 +289,9 @@ xfs_bmapi(
 	xfs_extlen_t		total,		/* total blocks needed */
 	struct xfs_bmbt_irec	*mval,		/* output: map values */
 	int			*nmap,		/* i/o: mval size/count */
-	xfs_bmap_free_t		*flist);	/* i/o: list extents to free */
+	xfs_bmap_free_t		*flist,		/* i/o: list extents to free */
+	xfs_extdelta_t		*delta);	/* o: change made to incore
+						   extents */
 
 /*
  * Map file blocks to filesystem blocks, simple version.
@@ -309,6 +325,8 @@ xfs_bunmapi(
 	xfs_fsblock_t		*firstblock,	/* first allocated block
 						   controls a.g. for allocs */
 	xfs_bmap_free_t		*flist,		/* i/o: list extents to free */
+	xfs_extdelta_t		*delta,		/* o: change made to incore
+						   extents */
 	int			*done);		/* set if not done yet */
 
 /*