btrfs/022: Match qgroup id more correctly
[BUG]
Btrfs/022 sometimes fails with snapshot's reference mismatch with its
source.
[CAUSE]
Since commit
fd0830929573 ("fsstress: add the ability to create
snapshots") adds the ability for fsstress to create/delete snapshot and
subvolumes, fsstress will create new subvolumes under test dir.
For example, we could have the following subvolumes created by fsstress:
subvol a id=256
subvol b id=306
qgroupid rfer excl
-------- ---- ----
0/5 16384 16384
0/256
13914112 16384
...
0/263
3080192 2306048 << 2 *306* 048
...
0/306
13914112 16384 << 0/ *306
So when we're greping for subvolid 306, it matches qgroup 0/263 first,
which has difference size, and caused false alert.
[FIX]
Instead of greping "$subvolid" blindly, now grep "0/$subvolid" to catch
qgroupid correctly, without hitting rfer/excl values.
Suggested-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>