Re: + zswap-make-zswap_load-take-a-folio-fix.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 11 Aug 2023 13:20:44 +0800 "Yin, Fengwei" <fengwei.yin@intel.com> wrote:

> 
> 
> On 8/11/2023 12:11 PM, Matthew Wilcox wrote:
> > On Thu, Aug 10, 2023 at 09:35:37AM -0700, Andrew Morton wrote:
> >>
> >> The patch titled
> >>      Subject: zswap: don't warn if none swapcache folio is passed to zswap_load
> >> has been added to the -mm mm-unstable branch.  Its filename is
> >>      zswap-make-zswap_load-take-a-folio-fix.patch
> > 
> > Disagree that this is a fix patch.  My original patch does:
> Agree with Matthew. The warning was not introduced by Matthew's patch.
> 
> > 
> > -       VM_WARN_ON_ONCE(!PageLocked(page));
> > -       VM_WARN_ON_ONCE(!PageSwapCache(page));
> > +       VM_WARN_ON_ONCE(!folio_test_locked(folio));
> > +       VM_WARN_ON_ONCE(!folio_test_swapcache(folio));
> > 
> > so I didn't add a new assertion, merely removed a call to
> > compound_head().  I think this patch deserves to stand on its own and
> > not be folded into mine.
> > 

OK, so it seems these assertions were added by hannes's "mm: kill
frontswap"
(https://lkml.kernel.org/r/20230717160227.GA867137@cmpxchg.org).  I'm
not really sure why - they don't appear to have been moved from
elsewhere.

So I'll requeue this as a fix against mm-kill-frontswap.patch.

The same two assertions were added to zswap_store().  Are they correct?