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From:   Andreas Gruenbacher <agruenba@redhat.com>
Date:   Mon, 19 Oct 2020 15:45:35 +0200
Message-ID: <CAHc6FU7TsdKopGCHo-PEJYr2gN7cpai+1YkfZ8=WNMSyX_Pk+g@mail.gmail.com>
Subject: Re: [PATCH] gfs2: use helper macro abs()
To:     Xianting Tian <tian.xianting@h3c.com>
Cc:     Bob Peterson <rpeterso@redhat.com>,
        cluster-devel <cluster-devel@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>
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Hi,

On Mon, Oct 19, 2020 at 10:03 AM Xianting Tian <tian.xianting@h3c.com> wrote:
> Use helper macro abs() to simplify the "x >= y || x <= -y" cmp.
>
> Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
> ---
>  fs/gfs2/super.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
> index 9f4d9e7be..05eb709de 100644
> --- a/fs/gfs2/super.c
> +++ b/fs/gfs2/super.c
> @@ -304,7 +304,7 @@ void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
>         if (sdp->sd_args.ar_statfs_percent) {
>                 x = 100 * l_sc->sc_free;
>                 y = m_sc->sc_free * sdp->sd_args.ar_statfs_percent;
> -               if (x >= y || x <= -y)
> +               if (abs(x) >= y)

x and y are signed values, so this really doesn't seem right.

>                         need_sync = 1;
>         }
>         spin_unlock(&sdp->sd_statfs_spin);
> --
> 2.17.1

Thanks,
Andreas