Re: [PATCH 2/3] fstests: btrfs/022: Match qgroup id more correctly

[Qu Wenruo <wqu@suse.com>]

On 2020/2/7 下午5:46, Nikolay Borisov wrote:
> 
> 
> On 7.02.20 г. 3:59 ч., Qu Wenruo wrote:
>> [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.
> 
> That 0/ can it ever be a number different than 0, if so a more correct
> regular expression should be:
> grep "[[:digit:]]/306"  ?

In this particular case, we only care level 0 qgroup, thus it's enough.

If we're extracting it into a generic wrapper, then your
[[:digit:]]/$subvolid will be needed.

Thanks,
Qu
> 
> 
>>
>> Suggested-by: Josef Bacik <josef@toxicpanda.com>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>>  tests/btrfs/022 | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/tests/btrfs/022 b/tests/btrfs/022
>> index 5348d3ed..3e729852 100755
>> --- a/tests/btrfs/022
>> +++ b/tests/btrfs/022
>> @@ -49,10 +49,10 @@ _basic_test()
>>  
>>  	# the shared values of both the original subvol and snapshot should
>>  	# match
>> -	a_shared=$($BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | grep $subvolid)
>> +	a_shared=$($BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | grep "0/$subvolid")
>>  	a_shared=$(echo $a_shared | awk '{ print $2 }')
>>  	subvolid=$(_btrfs_get_subvolid $SCRATCH_MNT b)
>> -	b_shared=$($BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | grep $subvolid)
>> +	b_shared=$($BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | grep "0/$subvolid")
>>  	b_shared=$(echo $b_shared | awk '{ print $2 }')
>>  	[ $b_shared -eq $a_shared ] || _fail "shared values don't match"
>>  }
>> @@ -68,12 +68,12 @@ _rescan_test()
>>  	run_check $FSSTRESS_PROG -d $SCRATCH_MNT/a -w -p 1 -n 2000 \
>>  		$FSSTRESS_AVOID
>>  	sync
>> -	output=$($BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | grep $subvolid)
>> +	output=$($BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | grep "0/$subvolid")
>>  	echo $output >> $seqres.full
>>  	refer=$(echo $output | awk '{ print $2 }')
>>  	excl=$(echo $output | awk '{ print $3 }')
>>  	_run_btrfs_util_prog quota rescan -w $SCRATCH_MNT
>> -	output=$($BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | grep $subvolid)
>> +	output=$($BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | grep "0/$subvolid")
>>  	echo $output >> $seqres.full
>>  	[ $refer -eq $(echo $output | awk '{ print $2 }') ] || \
>>  		_fail "reference values don't match after rescan"
>>