Re: Should we consider disable generic/563 for file systems that do not support cgroup2?

On Sat, 2026-07-18 at 00:19 +0800, Zorro Lang wrote:
> On Fri, Jul 10, 2026 at 07:10:43PM +0000, Viacheslav Dubeyko wrote:
> > Hello,
> > 
> > As far as I can see, the generic/563 test is dedicated to cgroup v2
> > functionality. And several file systems fails to execute the test:
> > 
> > sudo ./check generic/563
> > FSTYP         -- hfsplus
> > PLATFORM      -- Linux/x86_64 hfsplus-testing-0001 7.2.0-rc1+ #55
> > SMP
> > PREEMPT_DYNAMIC Fri Jul 10 11:21:38 PDT 2026
> > MKFS_OPTIONS  -- /dev/loop51
> > MOUNT_OPTIONS -- /dev/loop51 /mnt/scratch
> > 
> > generic/563        - output mismatch (see xfstests-
> > dev/results//generic/563.out.bad)
> >     --- tests/generic/563.out	2026-04-07 14:19:04.785079940 -
> > 0700
> >     +++ xfstests-dev/results//generic/563.out.bad	2026-07-10
> > 11:33:14.231562955 -0700
> >     @@ -4,11 +4,13 @@
> >      write is in range
> >      write -> read/write
> >      read is in range
> >     -write is in range
> >     +write has value of 0
> >     +write is NOT in range 15938355.2 .. 17616076.8
> >      read is in range
> >     ...
> >     (Run 'diff -u xfstests-dev/tests/generic/563.out xfstests-
> > dev/results//generic/563.out.bad'  to see the entire diff)
> > Ran: generic/563
> > Failures: generic/563
> > Failed 1 of 1 tests
> > 
> > sudo ./check generic/563
> > FSTYP         -- vfat
> > PLATFORM      -- Linux/x86_64 hfsplus-testing-0001 7.2.0-rc1+ #55
> > SMP
> > PREEMPT_DYNAMIC Fri Jul 10 11:21:38 PDT 2026
> > MKFS_OPTIONS  -- /dev/loop51
> > MOUNT_OPTIONS -- /dev/loop51 /mnt/scratch
> > 
> > generic/563        - output mismatch (see xfstests-
> > dev/results//generic/563.out.bad)
> >     --- tests/generic/563.out	2026-04-07 14:19:04.785079940 -
> > 0700
> >     +++ xfstests-dev/results//generic/563.out.bad	2026-07-10
> > 11:36:02.221320239 -0700
> >     @@ -1,14 +1,19 @@
> >      QA output created by 563
> >      read/write
> >     -read is in range
> >     +read has value of 22014464
> >     +read is NOT in range 15938355.2 .. 17616076.8
> >      write is in range
> >      write -> read/write
> >     ...
> >     (Run 'diff -u xfstests-dev/tests/generic/563.out xfstests-
> > dev/results//generic/563.out.bad'  to see the entire diff)
> > Ran: generic/563
> > Failures: generic/563
> > Failed 1 of 1 tests
> > 
> > sudo ./check generic/563
> > FSTYP         -- nilfs2
> > PLATFORM      -- Linux/x86_64 hfsplus-testing-0001 7.2.0-rc1+ #55
> > SMP
> > PREEMPT_DYNAMIC Fri Jul 10 11:21:38 PDT 2026
> > MKFS_OPTIONS  -- /dev/loop51
> > MOUNT_OPTIONS -- /dev/loop51 /mnt/scratch
> > 
> > generic/563        - output mismatch (see xfstests-
> > dev/results//generic/563.out.bad)
> >     --- tests/generic/563.out	2026-04-07 14:19:04.785079940 -
> > 0700
> >     +++ xfstests-dev/results//generic/563.out.bad	2026-07-10
> > 11:37:57.633280743 -0700
> >     @@ -1,14 +1,18 @@
> >      QA output created by 563
> >      read/write
> >      read is in range
> >     -write is in range
> >     +write has value of 0
> >     +write is NOT in range 15938355.2 .. 17616076.8
> >      write -> read/write
> >     ...
> >     (Run 'diff -u xfstests-dev/tests/generic/563.out xfstests-
> > dev/results//generic/563.out.bad'  to see the entire diff)
> > Ran: generic/563
> > Failures: generic/563
> > Failed 1 of 1 tests
> > 
> > Should file system (like HFS/HFS+, for example) implement cgroup2
> > support to
> > pass the  generic/563 successfully? Is it generic enough test-case?
> > Should we
> > consider disable generic/563 for file systems that do not support
> > cgroup2?
> 
> Hi Viacheslav,
> 
> I completely understand your frustration. The "generic" test suite in
> fstests
> isn't a universal requirement document, so I can't really answer
> whether HFS+
> should support cgroup2 or not..
> 
> File systems that are not supported by fstests good enough,
> frequently run into
> false failures. When facing a test that is "destined" to fail on a
> specific
> $FSTYP, you have below options (maybe more):
> 
> 1. You can add this specific test (e.g., generic/563) to your daily
> local test
>    exclusion list, refer to the -e or -E options with the ./check
> script.
> 
> 2. You can modify the test case to explicitly skip a specific $FSTYP
> using the
>    _exclude_fs helper, along with a short comment explaining why.
> 
> 3. You can use or implement a _require_ function to check if a
> specific feature
>    is supported, which will gracefully _notrun the test if it's
> missing. While
>    _require_cgroup2() already exists, its granularity is currently
> too coarse to
>    _notrun for HFS. You might want to consider refining it or
> introducing a new
>    helper to help file systems like HFS+ _notrun properly.
> 
> I hope my reply help to clear something for you, please let me know
> if you have
> any further questions.
> 
> 

Hi Zorro,

Thanks for this explanation. I decided to take a deeper look into the
HFS+ related issue to better understand the root case. When I'll have
clear understanding what is going on in generic/563, then I'll be able
to select the proper solution. Currently, I haven't really good
understanding of the root case of issue for HFS+ case. Let me spend
more time on this. :)

Thanks,
Slava.