btrfs: Move checks from btrfs_wq_run_delayed_node to btrfs_balance_delayed_items

btrfs_balance_delayed_items is the sole caller of
btrfs_wq_run_delayed_node and already includes one of the checks whether
the delayed inodes should be run. On the other hand
btrfs_wq_run_delayed_node duplicates that check and performs an
additional one for wq congestion.

Let's remove the duplicate check and move the congestion one in
btrfs_balance_delayed_items, leaving btrfs_wq_run_delayed_node to only
care about setting up the wq run. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/delayed-inode.c

@@ -1350,10 +1350,6 @@ static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
 {
 	struct btrfs_async_delayed_work *async_work;
 
-	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND ||
-	    btrfs_workqueue_normal_congested(fs_info->delayed_workers))
-		return 0;
-
 	async_work = kmalloc(sizeof(*async_work), GFP_NOFS);
 	if (!async_work)
 		return -ENOMEM;
@@ -1389,7 +1385,8 @@ void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_delayed_root *delayed_root = fs_info->delayed_root;
 
-	if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
+	if ((atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND) ||
+		btrfs_workqueue_normal_congested(fs_info->delayed_workers))
 		return;
 
 	if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {