nfs41: add range to layoutreturn args

So that callers can specify which range to return.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <loghyr@primarydata.com>
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 6400a1e0..3637923 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -293,7 +293,7 @@
 	struct nfs4_sequence_args seq_args;
 	struct pnfs_layout_hdr *layout;
 	struct inode *inode;
-	enum pnfs_iomode iomode;
+	struct pnfs_layout_range range;
 	nfs4_stateid stateid;
 	__u32   layout_type;
 };