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Date: Sat, 9 Dec 2017 20:59:22 +0000
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Michal Hocko <mhocko@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>, Jan Kara <jack@suse.cz>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        LKML <linux-kernel@vger.kernel.org>, linux-fsdevel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v2] fs: handle shrinker registration failure in
 sget_userns
Message-ID: <20171209205922.GM21978@ZenIV.linux.org.uk>
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On Wed, Nov 29, 2017 at 12:55:15PM +0100, Michal Hocko wrote:
> 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.

Is it in any git branch I could pull from?  Or I could just throw it
into vfs.git#for-linus before the fix above - up to you, folks...