Re: [RFC PATCH] mm/slab: fix a memory leak on kobject_init_and_add() failure

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

On Wed, Oct 23, 2024 at 1:08 AM Christoph Lameter (Ampere)
<cl@gentwo.org> wrote:
>
> On Tue, 22 Oct 2024, Vlastimil Babka wrote:
>
> > On 10/21/24 18:27, Christoph Lameter (Ampere) wrote:
> > > On Mon, 21 Oct 2024, Vlastimil Babka wrote:
> > >
> > >> I think the comment "If this function returns an error, kobject_put() must
> > >> be called" means that *if* you want to destroy it due to the failure, you
> > >> must use kobject_put() and not e.g. kfree(). But IMHO it doesn't mean you
> > >> must destroy it because of the kobject_add() failure.
> > >
> > > Right. The simplest solution is to see the sysfs stuff as optional. If it
> >
> > To clarify, I only meant the case of boot caches processed for sysfs later.
> > I don't think we need to start ignoring all sysfs errors.
>
> Well not ignoring. Write something to the syslog. So it wont affect slab
> operations. /sys support is not critical to the slab subsystem operations
> and is often not used at all.
>
> If its conks out then it should be fixed but it should not impact current
> operations. We have had so many issues with sysfs support in the past that
> doing so would be wise to avoid future problems.

Both directions look fine to me. Christoph's approach would probably be better
for maintainability I think? Failing to create sysfs files is not a
critical problem anyway.