Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) client-ip=2620:137:e000::3:2;
MIME-Version: 1.0
References: <20230919045135.3635437-1-willy@infradead.org> <20230919045135.3635437-8-willy@infradead.org>
In-Reply-To: <20230919045135.3635437-8-willy@infradead.org>
From:   Andreas Gruenbacher <agruenba@redhat.com>
Date:   Wed, 20 Sep 2023 00:27:08 +0200
Message-ID: <CAHc6FU4-RSAsc-LWw2OuLDecofapd30OZhxyjVKLXzJNwh-ZoA@mail.gmail.com>
Subject: Re: [PATCH 07/26] gfs2; Convert gfs2_getjdatabuf to use a folio
To:     "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        linux-fsdevel@vger.kernel.org, gfs2@lists.linux.dev,
        linux-nilfs@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net,
        ntfs3@lists.linux.dev, ocfs2-devel@lists.linux.dev,
        reiserfs-devel@vger.kernel.org, linux-ext4@vger.kernel.org,
        Pankaj Raghav <p.raghav@samsung.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Thanks,

but this patch has an unwanted semicolon in the subject.

On Tue, Sep 19, 2023 at 7:00=E2=80=AFAM Matthew Wilcox (Oracle)
<willy@infradead.org> wrote:
>
> Use the folio APIs, saving four hidden calls to compound_head().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  fs/gfs2/meta_io.c | 22 ++++++++--------------
>  1 file changed, 8 insertions(+), 14 deletions(-)
>
> diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
> index f1fac1b45059..b28196015543 100644
> --- a/fs/gfs2/meta_io.c
> +++ b/fs/gfs2/meta_io.c
> @@ -400,26 +400,20 @@ static struct buffer_head *gfs2_getjdatabuf(struct =
gfs2_inode *ip, u64 blkno)
>  {
>         struct address_space *mapping =3D ip->i_inode.i_mapping;
>         struct gfs2_sbd *sdp =3D GFS2_SB(&ip->i_inode);
> -       struct page *page;
> +       struct folio *folio;
>         struct buffer_head *bh;
>         unsigned int shift =3D PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
>         unsigned long index =3D blkno >> shift; /* convert block to page =
*/
>         unsigned int bufnum =3D blkno - (index << shift);
>
> -       page =3D find_get_page_flags(mapping, index, FGP_LOCK|FGP_ACCESSE=
D);
> -       if (!page)
> -               return NULL;
> -       if (!page_has_buffers(page)) {
> -               unlock_page(page);
> -               put_page(page);
> +       folio =3D __filemap_get_folio(mapping, index, FGP_LOCK | FGP_ACCE=
SSED, 0);
> +       if (IS_ERR(folio))
>                 return NULL;
> -       }
> -       /* Locate header for our buffer within our page */
> -       for (bh =3D page_buffers(page); bufnum--; bh =3D bh->b_this_page)
> -               /* Do nothing */;
> -       get_bh(bh);
> -       unlock_page(page);
> -       put_page(page);
> +       bh =3D folio_buffers(folio);
> +       if (bh)
> +               get_nth_bh(bh, bufnum);

And we need this here:

    bh =3D get_nth_bh(bh, bufnum);

> +       folio_unlock(folio);
> +       folio_put(folio);
>         return bh;
>  }
>
> --
> 2.40.1
>
>

Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>