Btrfs: remove unused function btrfs_add_delayed_qgroup_reserve()

No longer used as of commit 5846a3c2 ("btrfs: qgroup: Fix a race in
delayed_ref which leads to abort trans").
Signed-off-by: Filipe Manana <fdmanana@suse.com>

fs/btrfs/delayed-ref.c

@@ -861,33 +861,6 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
-int btrfs_add_delayed_qgroup_reserve(struct btrfs_fs_info *fs_info,
-				     struct btrfs_trans_handle *trans,
-				     u64 ref_root, u64 bytenr, u64 num_bytes)
-{
-	struct btrfs_delayed_ref_root *delayed_refs;
-	struct btrfs_delayed_ref_head *ref_head;
-	int ret = 0;
-
-	if (!fs_info->quota_enabled || !is_fstree(ref_root))
-		return 0;
-
-	delayed_refs = &trans->transaction->delayed_refs;
-
-	spin_lock(&delayed_refs->lock);
-	ref_head = find_ref_head(&delayed_refs->href_root, bytenr, 0);
-	if (!ref_head) {
-		ret = -ENOENT;
-		goto out;
-	}
-	WARN_ON(ref_head->qgroup_reserved || ref_head->qgroup_ref_root);
-	ref_head->qgroup_ref_root = ref_root;
-	ref_head->qgroup_reserved = num_bytes;
-out:
-	spin_unlock(&delayed_refs->lock);
-	return ret;
-}
-
 int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
 				struct btrfs_trans_handle *trans,
 				u64 bytenr, u64 num_bytes,

fs/btrfs/delayed-ref.h

@@ -250,9 +250,6 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
 			       u64 parent, u64 ref_root,
 			       u64 owner, u64 offset, u64 reserved, int action,
 			       struct btrfs_delayed_extent_op *extent_op);
-int btrfs_add_delayed_qgroup_reserve(struct btrfs_fs_info *fs_info,
-				     struct btrfs_trans_handle *trans,
-				     u64 ref_root, u64 bytenr, u64 num_bytes);
 int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
 				struct btrfs_trans_handle *trans,
 				u64 bytenr, u64 num_bytes,