Re: [PATCH] z3fold: fix retry mechanism in page reclaim

From: Vitaly Wool
Date: Sun Sep 08 2019 - 16:44:49 EST


On Sun, Sep 8, 2019 at 4:56 PM Maciej S. Szmigiero
<mail@xxxxxxxxxxxxxxxxxxxxx> wrote:
>
> On 08.09.2019 15:29, Vitaly Wool wrote:
> > z3fold_page_reclaim()'s retry mechanism is broken: on a second
> > iteration it will have zhdr from the first one so that zhdr
> > is no longer in line with struct page. That leads to crashes when
> > the system is stressed.
> >
> > Fix that by moving zhdr assignment up.
> >
> > While at it, protect against using already freed handles by using
> > own local slots structure in z3fold_page_reclaim().
> >
> > Reported-by: Markus Linnala <markus.linnala@xxxxxxxxx>
> > Reported-by: Chris Murphy <bugzilla@xxxxxxxxxxxxxxxxx>
> > Reported-by: Agustin Dall'Alba <agustin@xxxxxxxxxxxxxxx>
> > Signed-off-by: Vitaly Wool <vitalywool@xxxxxxxxx>
> > ---
>
> Shouldn't this be CC'ed to stable@ ?

I guess :)

Thanks,
Vitaly