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From:   Stephen Zhang <starzhangzsd@gmail.com>
Date:   Tue, 21 Jun 2022 15:04:20 +0800
Message-ID: <CANubcdUO55kSFc7USg-EsgE5uvQR08s8wcxrf4=vHk8VOiisjw@mail.gmail.com>
Subject: Re: [PATCH] xfs: return when delta equals 0 in xfs_mod_freecounter
To:     Dave Chinner <david@fromorbit.com>
Cc:     djwong@kernel.org, zhangshida <zhangshida@kylinos.cn>,
        linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org
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Dave Chinner <david@fromorbit.com> =E4=BA=8E2022=E5=B9=B46=E6=9C=8821=E6=97=
=A5=E5=91=A8=E4=BA=8C 12:35=E5=86=99=E9=81=93=EF=BC=9A
>
> On Tue, Jun 21, 2022 at 11:11:13AM +0800, Shida Zhang wrote:
> > There are cases that xfs_mod_freecounter() will get called when delta
> > equals 0 while it's unnecessary.
>
> AFAICT all of the call paths are guarded by checks to ensure the
> delta is, in fact, not zero. i.e. if the delta is zero, we shouldn't
> be calling xfs_mod_fdblocks() or xfs_mod_frextents() at all.
>
> Can you explain in more detail what code path leads to delta =3D 0
> here?
>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@fromorbit.com

Yeah. I will give it in another v2 version patch.

Cheers,

Stephen.