xfs: support bmapping delalloc extents in the CoW fork

Allow the creation of delayed allocation extents in the CoW fork.  In
a subsequent patch we'll wire up iomap_begin to actually do this via
reflink helper functions.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index 8774127..c6fd52f 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -234,9 +234,10 @@
 	xfs_bmap_search_extents(struct xfs_inode *ip, xfs_fileoff_t bno,
 		int fork, int *eofp, xfs_extnum_t *lastxp,
 		struct xfs_bmbt_irec *gotp, struct xfs_bmbt_irec *prevp);
-int	xfs_bmapi_reserve_delalloc(struct xfs_inode *ip, xfs_fileoff_t aoff,
-		xfs_filblks_t len, struct xfs_bmbt_irec *got,
-		struct xfs_bmbt_irec *prev, xfs_extnum_t *lastx, int eof);
+int	xfs_bmapi_reserve_delalloc(struct xfs_inode *ip, int whichfork,
+		xfs_fileoff_t aoff, xfs_filblks_t len,
+		struct xfs_bmbt_irec *got, struct xfs_bmbt_irec *prev,
+		xfs_extnum_t *lastx, int eof);
 
 enum xfs_bmap_intent_type {
 	XFS_BMAP_MAP = 1,