[PATCH] map multiple blocks for mpage_readpages()

This patch changes mpage_readpages() and get_block() to get the disk mapping
information for multiple blocks at the same time.

b_size represents the amount of disk mapping that needs to mapped.  On the
successful get_block() b_size indicates the amount of disk mapping thats
actually mapped.  Only the filesystems who care to use this information and
provide multiple disk blocks at a time can choose to do so.

No changes are needed for the filesystems who wants to ignore this.

[akpm@osdl.org: cleanups]
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 4f2476f..a79b84f 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -1310,8 +1310,9 @@
 	struct buffer_head	*bh_result,
 	int			create)
 {
-	return __xfs_get_block(inode, iblock, 0, bh_result,
-					create, 0, BMAPI_WRITE);
+	return __xfs_get_block(inode, iblock,
+				bh_result->b_size >> inode->i_blkbits,
+				bh_result, create, 0, BMAPI_WRITE);
 }
 
 STATIC int