Re: [PATCH 2/2] selftests/fuse: add ACL_DONT_CACHE regression test

[Luis Henriques <luis@igalia.com>]

On Thu, Jul 16 2026, Chen Linxuan wrote:

> On Thu Jul 16, 2026 at 6:10 PM CST, Amir Goldstein wrote:
>> On Wed, Jul 15, 2026 at 10:41 PM Luis Henriques <luis@igalia.com> wrote:
>>>
>>> Hi!
>>>
>>> On Wed, Jul 15 2026, Amir Goldstein wrote:
>>>
>>> [...]
>>> >> A question: in my own tests I have been following a different approach,
>>> >> where the filesystem is mounted from a shell script that does the actual
>>> >> testing.  I wonder if you think your approach (i.e. writing the actual
>>> >> test in C, using the kselftest macros) is the preferred one.
>>> >
>>> > I always prefer a standalone C program for a selftest.
>>> > For fstests naturally the tests are done by the shell scripts,
>>> > so it really depends.
>>>
>>> Cool, thanks.  I'll consider adapting my own tests to have a similar
>>> format as this one.
>>>
>>> >> Anyway, the test looks good to me, and I just have a few minor comments
>>> >> below.
>>> >>
>>> >> > fuse_acl_cache_test is only built when libfuse3 is detected via
>>> >> > pkg-config.
>>> >>
>>> >> Yeah, I've sent a patch recently converting the only existing test to also
>>> >> user fuse3 instead.  Not sure that's acceptable though, since there's a
>>> >> chance of breaking some CI.
>>> >
>>> > I mean if the test is not built it wont run, so I don't know why CI would fail.
>>> > Obviously some systems do not have libfuse. That's fine by me
>>> > not everyone needs to run all the tests.
>>>
>>> Oh! as usual my comment wasn't clear :-)
>>>
>>> In fact, my comment wasn't really very relevant in the context of this
>>> patch as, in my opinion, I think it's OK for new tests to depend on fuse3.
>>>
>>> I was talking about my own patch[1] which was converting the existing
>>> test, which depends on fuse2, to use fuse3.  That's what I was referring
>>> to when talking about breaking CI: we could have a scenario where a test
>>> was being built and executed and, because it's now using fuse3, it can't
>>> be built any more.
>>>
>>> [1] https://lore.kernel.org/all/20260708131122.2917-3-luis@igalia.com/
>>>
>>
>> CC test author
>> I think your concern is exaggerated
>> This test is 1 year old. Who runs this test and doesn't have fuse3?
>
> A quick note on why it used fuse2 to begin with: back then there was no
> fuse3-based test anywhere in the selftests tree. Amir actually pointed me
> to tools/testing/selftests/memfd [1] as the reference to follow, and
> that one (both its Makefile and fuse_mnt.c) is built on libfuse2, so I
> simply copied that pattern for consistency.

Ah! I wasn't aware there was yet another selftest relying on fuse2.
Thanks a lot for pointing that out.  It now makes sense -- that's a very
old test.

Cheers,
-- 
Luís