Re: [PATCH 1/2] common/dmlogwrites: add _require_logwrites_size helper

[Disha Goel <disgoel@linux.ibm.com>]

On 22/04/26 9:25 pm, Darrick J. Wong wrote:
> On Wed, Apr 22, 2026 at 11:08:34AM +0530, Disha Goel wrote:
>> Hi,
>>
>> Looking for review comments on this patch series.
>>
>> On 14/04/26 3:50 pm, Disha Goel wrote:
>>> Add a new helper function _require_logwrites_size() to check if the
>>> LOGWRITES_DEV meets a minimum size requirement.
>>>
>>> This is useful for tests that use dm-log-writes with additional space
>>> requirements, such as creating LVM snapshots during log replay or tests
>>> that generate large amounts of logged I/O operations.
>>>
>>> The function takes a size parameter in KB and skips the test if
>>> LOGWRITES_DEV is smaller than the required size.
>>>
>>> Signed-off-by: Disha Goel <disgoel@linux.ibm.com>
>>> ---
>>>    common/dmlogwrites | 9 +++++++++
>>>    1 file changed, 9 insertions(+)
>>>
>>> diff --git a/common/dmlogwrites b/common/dmlogwrites
>>> index a27e1966..1ce2b2fb 100644
>>> --- a/common/dmlogwrites
>>> +++ b/common/dmlogwrites
>>> @@ -14,6 +14,15 @@ _require_log_writes()
>>>    	_require_test_program "log-writes/replay-log"
>>>    }
>>> +_require_logwrites_size()
>>> +{
>>> +        [ $# -eq 1 ] || _fail "_require_logwrites_size: expected size param"
> 
> What are the units of the size parameter?  Bytes?  512b sectors?
> 
> The helper should have a comment clarifying that.
> 
> --D
> 
Thanks for the review. I've addressed this in v2 by adding a comment 
block documenting that the parameter is in KB.

v2 has been sent: 
https://lore.kernel.org/fstests/20260427122551.71696-1-disgoel@linux.ibm.com/T/#t

>>> +
>>> +        local devsize=$(_get_device_size $LOGWRITES_DEV)
>>> +        [ $devsize -lt $1 ] && \
>>> +                _notrun "LOGWRITES_DEV too small, ${devsize}KB < $1KB"
>>> +}
>>> +
>>>    # Starting from v4.15-rc1, DAX support was added to dm-log-writes, but note
>>>    # that it doesn't track the data that we write via the mmap(), so we can't do
>>>    # any data integrity checking. We can only verify that the metadata writes for
>>
>> -- 
>> Regards,
>> Disha
>>
>>

-- 
Regards,
Disha