Btrfs: Add inode flags support

This patch adds NODATASUM & NODATACOW inode flags support.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index f27e633..9fc9988 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -34,6 +34,7 @@
 	 * transid of the trans_handle that last modified this inode
 	 */
 	u64 last_trans;
+	u32 flags;
 };
 static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
 {