Commit a8df3561 authored by Boris Burkov's avatar Boris Burkov Committed by David Sterba
Browse files

btrfs: forbid deleting live subvol qgroup 



If a subvolume still exists, forbid deleting its qgroup 0/subvolid.
This behavior generally leads to incorrect behavior in squotas and
doesn't have a legitimate purpose.

Fixes: cecbb533 ("btrfs: record simple quota deltas in delayed refs")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarBoris Burkov <boris@bur.io>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 0c309d66

fs/btrfs/qgroup.c

+14 −0
Original line number Diff line number Diff line
@@ -1736,6 +1736,15 @@ int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid) 
	return ret;

}



static bool qgroup_has_usage(struct btrfs_qgroup *qgroup)

{

	return (qgroup->rfer > 0 || qgroup->rfer_cmpr > 0 ||

		qgroup->excl > 0 || qgroup->excl_cmpr > 0 ||

		qgroup->rsv.values[BTRFS_QGROUP_RSV_DATA] > 0 ||

		qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PREALLOC] > 0 ||

		qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PERTRANS] > 0);

}



int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)

{

	struct btrfs_fs_info *fs_info = trans->fs_info;
@@ -1755,6 +1764,11 @@ int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid) 
		goto out;

	}



	if (is_fstree(qgroupid) && qgroup_has_usage(qgroup)) {

		ret = -EBUSY;

		goto out;

	}



	/* Check if there are no children of this qgroup */

	if (!list_empty(&qgroup->members)) {

		ret = -EBUSY;