Re: [PATCH v2] fs: handle shrinker registration failure in sget_userns

From: Michal Hocko
Date: Wed Nov 29 2017 - 06:55:23 EST


On Thu 23-11-17 14:55:40, Al Viro wrote:
> On Thu, Nov 23, 2017 at 03:35:37PM +0100, Michal Hocko wrote:
> > Hopefully less screwed version. But as I've said I am not really
> > familiar with the code and do not feel competent to change it so please
> > be very careful here. I've moved the shrinker registration to
> > alloc_super which turned out to be simpler.
>
> I don't get it. Why the hell do we need all that PITA in the first place?
> Just make sget_userns() end with
> if (unlikely(regsiter_shrinker(&s->s_shrink) != 0)) {
> deactivate_locked_super(s);
> s = ERR_PTR(-ENOMEM);
> }
> return s;
> and be done with that. All there is to it...

Al, do you plan to push this fix? Tetsuo's unregister_shrinker
fortification is already in the mmotm tree.
--
Michal Hocko
SUSE Labs