btrfs: delayed-ref: pass delayed_refs directly to btrfs_delayed_ref_lock

Since trans is only used for referring to delayed_refs, there is no need
to pass it instead of delayed_refs to btrfs_delayed_ref_lock().

No functional change.
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NLu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/delayed-ref.c

@@ -204,12 +204,9 @@ static struct btrfs_delayed_ref_head* find_ref_head(
 	return NULL;
 }
 
-int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
+int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
 			   struct btrfs_delayed_ref_head *head)
 {
-	struct btrfs_delayed_ref_root *delayed_refs;
-
-	delayed_refs = &trans->transaction->delayed_refs;
 	lockdep_assert_held(&delayed_refs->lock);
 	if (mutex_trylock(&head->mutex))
 		return 0;

fs/btrfs/delayed-ref.h

@@ -255,7 +255,7 @@ void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
 struct btrfs_delayed_ref_head *
 btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
 			    u64 bytenr);
-int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
+int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
 			   struct btrfs_delayed_ref_head *head);
 static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
 {

fs/btrfs/extent-tree.c

@@ -2521,7 +2521,7 @@ static struct btrfs_delayed_ref_head *btrfs_obtain_ref_head(
 	 * Grab the lock that says we are going to process all the refs for
 	 * this head
 	 */
-	ret = btrfs_delayed_ref_lock(trans, head);
+	ret = btrfs_delayed_ref_lock(delayed_refs, head);
 	spin_unlock(&delayed_refs->lock);
 
 	/*