btrfs: Make btrfs_async_run_delayed_root use a loop rather than multiple labels

Currently btrfs_async_run_delayed_root's implementation uses 3 goto
labels to mimic the functionality of a simple do {} while loop. Refactor
the function to use a do {} while construct, making intention clear and
code easier to follow. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NQu Wenruo <wqu@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/delayed-inode.c

@@ -1302,20 +1302,25 @@ static void btrfs_async_run_delayed_root(struct btrfs_work *work)
 	if (!path)
 		goto out;
 
-again:
-	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND / 2)
-		goto free_path;
+	do {
+		if (atomic_read(&delayed_root->items) <
+		    BTRFS_DELAYED_BACKGROUND / 2)
+			break;
 
 		delayed_node = btrfs_first_prepared_delayed_node(delayed_root);
 		if (!delayed_node)
-		goto free_path;
+			break;
 
 		path->leave_spinning = 1;
 		root = delayed_node->root;
 
 		trans = btrfs_join_transaction(root);
-	if (IS_ERR(trans))
-		goto release_path;
+		if (IS_ERR(trans)) {
+			btrfs_release_path(path);
+			btrfs_release_prepared_delayed_node(delayed_node);
+			total_done++;
+			continue;
+		}
 
 		block_rsv = trans->block_rsv;
 		trans->block_rsv = &root->fs_info->delayed_block_rsv;
@@ -1326,16 +1331,13 @@ static void btrfs_async_run_delayed_root(struct btrfs_work *work)
 		btrfs_end_transaction(trans);
 		btrfs_btree_balance_dirty_nodelay(root->fs_info);
 
-release_path:
 		btrfs_release_path(path);
+		btrfs_release_prepared_delayed_node(delayed_node);
 		total_done++;
 
-	btrfs_release_prepared_delayed_node(delayed_node);
-	if ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK) ||
-	    total_done < async_work->nr)
-		goto again;
+	} while ((async_work->nr == 0 && total_done < BTRFS_DELAYED_WRITEBACK)
+		 || total_done < async_work->nr);
 
-free_path:
 	btrfs_free_path(path);
 out:
 	wake_up(&delayed_root->wait);