btrfs: change insert_dirty_subvol to return errors

This will be able to return errors in the future, so change it to return
an error and handle the errors appropriately.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/relocation.c

@@ -1565,9 +1565,9 @@ static int find_next_key(struct btrfs_path *path, int level,
 /*
  * Insert current subvolume into reloc_control::dirty_subvol_roots
  */
-static void insert_dirty_subvol(struct btrfs_trans_handle *trans,
-				struct reloc_control *rc,
-				struct btrfs_root *root)
+static int insert_dirty_subvol(struct btrfs_trans_handle *trans,
+			       struct reloc_control *rc,
+			       struct btrfs_root *root)
 {
 	struct btrfs_root *reloc_root = root->reloc_root;
 	struct btrfs_root_item *reloc_root_item;
@@ -1587,6 +1587,8 @@ static void insert_dirty_subvol(struct btrfs_trans_handle *trans,
 		btrfs_grab_root(root);
 		list_add_tail(&root->reloc_dirty_list, &rc->dirty_subvol_roots);
 	}
+
+	return 0;
 }
 
 static int clean_dirty_subvols(struct reloc_control *rc)
@@ -1788,8 +1790,11 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
 out:
 	btrfs_free_path(path);
 
-	if (ret == 0)
-		insert_dirty_subvol(trans, rc, root);
+	if (ret == 0) {
+		ret = insert_dirty_subvol(trans, rc, root);
+		if (ret)
+			btrfs_abort_transaction(trans, ret);
+	}
 
 	if (trans)
 		btrfs_end_transaction_throttle(trans);