btrfs: qgroup: Drop root parameter from update_qgroup_limit_item

It can be fetched from the transaction handle.
Signed-off-by: NLu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/qgroup.c

@@ -700,9 +700,9 @@ static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid)
 }
 
 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
-				    struct btrfs_root *root,
 				    struct btrfs_qgroup *qgroup)
 {
+	struct btrfs_root *quota_root = trans->fs_info->quota_root;
 	struct btrfs_path *path;
 	struct btrfs_key key;
 	struct extent_buffer *l;
@@ -718,7 +718,7 @@ static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
 	if (!path)
 		return -ENOMEM;
 
-	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 	if (ret > 0)
 		ret = -ENOENT;
 
@@ -1509,7 +1509,7 @@ int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
 
 	spin_unlock(&fs_info->qgroup_lock);
 
-	ret = update_qgroup_limit_item(trans, quota_root, qgroup);
+	ret = update_qgroup_limit_item(trans, qgroup);
 	if (ret) {
 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 		btrfs_info(fs_info, "unable to update quota limit for %llu",
@@ -2214,7 +2214,7 @@ int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
 		if (ret)
 			fs_info->qgroup_flags |=
 					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
-		ret = update_qgroup_limit_item(trans, quota_root, qgroup);
+		ret = update_qgroup_limit_item(trans, qgroup);
 		if (ret)
 			fs_info->qgroup_flags |=
 					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
@@ -2323,7 +2323,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
 		dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
 		dstgroup->rsv_excl = inherit->lim.rsv_excl;
 
-		ret = update_qgroup_limit_item(trans, quota_root, dstgroup);
+		ret = update_qgroup_limit_item(trans, dstgroup);
 		if (ret) {
 			fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 			btrfs_info(fs_info,