[XFS] Add new getbmap flags.

This adds a new output flag, BMV_OF_LAST to indicate if we've hit
the last extent in the inode.  This potentially saves an extra call
from userspace to see when the whole mapping is done.

It also adds BMV_IF_DELALLOC and BMV_OF_DELALLOC to request, and
indicate, delayed-allocation extents.  In this case bmv_block
is set to -2 (-1 was already taken for HOLESTARTBLOCK; unfortunately
these are the reverse of the in-kernel constants.)

These new flags facilitate addition of the new fiemap interface.

Rather than adding sh_delalloc, remove sh_unwritten & just test
the flags directly.

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
diff --git a/fs/xfs/xfs_fs.h b/fs/xfs/xfs_fs.h
index df859d6..4ae03ba 100644
--- a/fs/xfs/xfs_fs.h
+++ b/fs/xfs/xfs_fs.h
@@ -113,10 +113,14 @@
 #define BMV_IF_ATTRFORK		0x1	/* return attr fork rather than data */
 #define BMV_IF_NO_DMAPI_READ	0x2	/* Do not generate DMAPI read event  */
 #define BMV_IF_PREALLOC		0x4	/* rtn status BMV_OF_PREALLOC if req */
-#define BMV_IF_VALID	(BMV_IF_ATTRFORK|BMV_IF_NO_DMAPI_READ|BMV_IF_PREALLOC)
+#define BMV_IF_DELALLOC		0x8	/* rtn status BMV_OF_DELALLOC if req */
+#define BMV_IF_VALID	\
+	(BMV_IF_ATTRFORK|BMV_IF_NO_DMAPI_READ|BMV_IF_PREALLOC|BMV_IF_DELALLOC)
 
 /*	bmv_oflags values - returned for for each non-header segment */
 #define BMV_OF_PREALLOC		0x1	/* segment = unwritten pre-allocation */
+#define BMV_OF_DELALLOC		0x2	/* segment = delayed allocation */
+#define BMV_OF_LAST		0x4	/* segment is the last in the file */
 
 /*
  * Structure for XFS_IOC_FSSETDM.