Re: [PATCH v1] mm/slab: Allow cache creation to proceed even if sysfs registration fails

[Hyeonggon Yoo <42.hyeyoo@gmail.com>]

On Sat, Nov 2, 2024 at 7:07 PM Hyeonggon Yoo <42.hyeyoo@gmail.com> wrote:
>
> On Sat, Nov 2, 2024 at 5:50 PM Vlastimil Babka <vbabka@suse.cz> wrote:
> >
> > On 11/2/24 8:18 AM, Hyeonggon Yoo wrote:
> > >>
> > >> Also here, and simplified to "if (sysfs_slab_add(s)) ... " to avoid dealing
> > >> with err.
> > >
> > > Oh no. err is initialized to -EINVAL, so that will not work as intended.
> > > It is causing the following list corruption.
> >
> > Ooops, right, thanks a lot. Wrongly assumed that a test boot in
> > virtme-ng would catch silly mistakes like that. Looks like all caches
> > were created with SLAB_STATE < FULL.
> >
> > Fixed by setting err = 0 before trying sysfs add.
>
> Thanks!
>
> Hmm... by the way, why doesn't SLUB update 'err' in the event of an error in
> init_cache_random_seq(), init_kmem_cache_nodes(), or alloc_kmem_cache_cpus()?
> I may be missing something, but it doesn't seem to handle these errors
> properly to me...

Oh, it seems like a recent change fc0eac57d08c ("slab: pull kmem_cache_open()
into do_kmem_cache_create()") incorrectly pulled kmem_cache_open()?

Cc-ing Christian Brauner.