Re: [PATCH 2/2] xfs: Add test for mkfs with smaller zone capacity

[Johannes Thumshirn <Johannes.Thumshirn@wdc.com>]

On 11/24/25 4:27 PM, Carlos Maiolino wrote:
> On Fri, Nov 21, 2025 at 06:51:31AM +0000, Johannes Thumshirn wrote:
>> On 11/20/25 5:09 PM, cem@kernel.org wrote:
>>> From: Carlos Maiolino <cem@kernel.org>
>>>
>>> Add a regression test for initializing zoned block devices with
>>> sequential zones with a capacity smaller than the conventional
>>> zones capacity.
>>
>> Hi Carlos,
>>
>> Two quick questions:
>>
>> 1) Is there a specific reason this is a xfs only test? I think checking
>> this on btrfs and f2fs would make sense as well, like with generic/781.
> I wrote this mostly as a regression test for xfs's mkfs, but yeah, I don't
> think there is any reason for this to be xfs-specific.
>
>> 2)  I would also mount the FS and perform some IO on it.
> I'm not sure about this. Do you have any purpose in mind? This is
> specifically to test mkfs is able to properly format the filesystem, not
> to try the kernel module per-se.
> One could argue that something 'could' go wrong in the mkfs that might
> be found out only via some IO, but that would require much more than
> just 'some IO'.


Yep that's what I had in mind.


> I do think a mount/unmount might add some value to the test, but I fail
> to see why issuing a random amount of I/O would prove the correctness of
> mkfs properly dealing with small capacities.


fstests does a fsck after each test, doesn't it? So that should be 
sufficient as well.