Since commit aaf2dac5ef ("btrfs-progs: qgroup: split update_qgroup to
reduce arguments") cause qgroup show to output the wrong qgroup
parent-child relationship, in addition to fixing the problem, a test case
is needed to prevent the similar problem in the future.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
