Re: [PATCH bpf-next v2 1/3] selftests/bpf: do not disable /dev/null device access in cgroup dev test

[Alan Maguire <alan.maguire@oracle.com>]

On 29/07/2024 18:30, Alexis Lothoré wrote:
> Hello Alan,
> 
> On 7/29/24 18:59, Alan Maguire wrote:
>> On 29/07/2024 09:20, Alexis Lothoré (eBPF Foundation) wrote:
>>> test_dev_cgroup currently loads a small bpf program allowing any access on
>>> urandom and zero devices, disabling access to any other device. It makes
>>> migrating this test to test_progs impossible, since this one manipulates
>>> extensively /dev/null.
>>>
>>> Allow /dev/null manipulation in dev_cgroup program to make its usage in
>>> test_progs framework possible. Update test_dev_cgroup.c as well to match
>>> this change while it has not been removed.
>>>
>>> Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com>
>>> ---
>>>  tools/testing/selftests/bpf/progs/dev_cgroup.c |  4 ++--
>>>  tools/testing/selftests/bpf/test_dev_cgroup.c  | 18 +++++++++---------
>>
>> Not a big deal, but I found it a bit confusing that this file was
>> modified then deleted in patch 2. Would it work having patch 1 stop
>> building the standalone test/remove it and .gitignore entry, patch 2
>> updating progs/dev_cgroup.c to allow /dev/zero, /dev/urandom access,
>> patch 3 add cgroup_dev.c test support, and patch 4 add the device type
>> subtest? Or are there issues with doing things that way? Thanks!
> 
> I've done this to make sure that at any point in the git history, there is one
> working test for the targeted feature, either the old or the new one. I've done
> it this way because the old test also helped me validate the new one while
> developing it, but also because if at some point there is a (major) issue with
> the new test, reverting only the relevant commit brings back the old test while
> disabling the new one.
> 
> But maybe this concern is not worth the trouble (especially since the old tests
> are not run automatically) ? If that's indeed the case, I can do it the way you
> are suggesting :)
>

If no-one complains, it seems fine to me to stick with the way you've
constructed the series the next respin. Thanks!

> Thanks,
> 
> Alexis
>