Btrfs: Fix data=ordered vs wait_on_inode deadlock on older kernels

Using ilookup5 during data=ordered writeback could deadlock on I_LOCK.  This
saves a pointer to the inode instead.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 26b2621..f25c677 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -33,8 +33,10 @@
 
 int btrfs_add_ordered_inode(struct inode *inode);
 int btrfs_find_del_first_ordered_inode(struct btrfs_ordered_inode_tree *tree,
-				       u64 *root_objectid, u64 *objectid);
+				       u64 *root_objectid, u64 *objectid,
+				       struct inode **inode);
 int btrfs_find_first_ordered_inode(struct btrfs_ordered_inode_tree *tree,
-				       u64 *root_objectid, u64 *objectid);
+				       u64 *root_objectid, u64 *objectid,
+				       struct inode **inode);
 int btrfs_del_ordered_inode(struct inode *inode);
 #endif