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References: <20201003063143.13093-1-foxhlchen@gmail.com>
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From:   Andreas Gruenbacher <agruenba@redhat.com>
Date:   Mon, 5 Oct 2020 14:59:44 +0200
Message-ID: <CAHc6FU4--0duukwCutZGct_0hgrkCr3Rcje6QRWVwM7rdDTsjQ@mail.gmail.com>
Subject: Re: [PATCH] gfs2: gfs2_read_sb: put gfs2_assert inside the loop
To:     Fox Chen <foxhlchen@gmail.com>
Cc:     Bob Peterson <rpeterso@redhat.com>,
        cluster-devel <cluster-devel@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Hi Fox Chen,

On Sat, Oct 3, 2020 at 8:33 AM Fox Chen <foxhlchen@gmail.com> wrote:
> Before this patch, gfs2_assert is put outside of the loop of
> sdp->sd_heightsize[x] calculation. When something goes wrong,
> x exceeds the size of GFS2_MAX_META_HEIGHT, it may already crash inside
> the loop when
>
> sdp->sd_heightsize[x] = space
>
> tries to reach the out-of-bound
> location, gfs2_assert won't help here.

that's true, but the smallest possible block size is 1024 bytes, and
with that, the height cannot grow bigger than 10. So the assert is
basically there only for documentation purposes.

Thanks,
Andreas