MIME-Version: 1.0
References: <20211111084617.6746-1-ajaygargnsit@gmail.com> <6864f744-ca3e-f328-8793-2adb0146db03@bytedance.com>
 <CAHP4M8VNZY+NLzUAVHTWK6a6pggvv4a-q9nvYAqkkco6id3Tog@mail.gmail.com>
In-Reply-To: <CAHP4M8VNZY+NLzUAVHTWK6a6pggvv4a-q9nvYAqkkco6id3Tog@mail.gmail.com>
From:   Muchun Song <songmuchun@bytedance.com>
Date:   Thu, 11 Nov 2021 20:11:56 +0800
Message-ID: <CAMZfGtXCFJ3NUw-bBsphLbCtdDAfHERAEkTSMU9k1cfd4DrRMA@mail.gmail.com>
Subject: Re: [PATCH] mm: shmem: do not call PageHWPoison on a ERR-page
To:     Ajay Garg <ajaygargnsit@gmail.com>
Cc:     Hugh Dickins <hughd@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, Nov 11, 2021 at 7:40 PM Ajay Garg <ajaygargnsit@gmail.com> wrote:
>
> >
> > How about the following changes since the above if block
> > already do the judgment?
> >
> > diff --git a/mm/shmem.c b/mm/shmem.c
> > index f0eee4e221a7..0c84b6624026 100644
> > --- a/mm/shmem.c
> > +++ b/mm/shmem.c
> > @@ -4195,13 +4195,13 @@ struct page *shmem_read_mapping_page_gfp(struct
> > address_space *mapping,
> >          BUG_ON(!shmem_mapping(mapping));
> >          error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE,
> >                                    gfp, NULL, NULL, NULL);
> > -       if (error)
> > +       if (error) {
> >                  page = ERR_PTR(error);
> > -       else
> > +       } else {
> >                  unlock_page(page);
> > -
> > -       if (PageHWPoison(page))
> > -               page = ERR_PTR(-EIO);
> > +               if (PageHWPoison(page))
> > +                       page = ERR_PTR(-EIO);
> > +       }
> >
> >          return page;
>
>
> You have
>
> * simply put braces (not required for 1-liner if/else blocks)
> * contributed nothing to the issue the patch addresses.
>
> I hope this is not a deliberate joke/spam.

What? I put "if (PageHWPoison(page))" into the else branch,
it should be added braces since it's not 1-line blocks. Why do
you think it does not address the issue? What am I missing
here?