Btrfs: Throttle file_write when data=ordered is flushing the inode

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index f25c677..29047e0 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -39,4 +39,5 @@
 				       u64 *root_objectid, u64 *objectid,
 				       struct inode **inode);
 int btrfs_del_ordered_inode(struct inode *inode);
+int btrfs_ordered_throttle(struct btrfs_root *root, struct inode *inode);
 #endif