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From:   Hao Sun <sunhao.th@gmail.com>
Date:   Fri, 8 Oct 2021 11:02:14 +0800
Message-ID: <CACkBjsZ8vxzSAnhVqnkJwQi1a5oCddGRZrK5bmvUQYzDKBDsjw@mail.gmail.com>
Subject: Re: kernel BUG in block_invalidatepage
To:     Matthew Wilcox <willy@infradead.org>
Cc:     Jens Axboe <axboe@kernel.dk>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org,
        linux-block@vger.kernel.org
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Matthew Wilcox <willy@infradead.org> =E4=BA=8E2021=E5=B9=B410=E6=9C=887=E6=
=97=A5=E5=91=A8=E5=9B=9B =E4=B8=8B=E5=8D=8810:20=E5=86=99=E9=81=93=EF=BC=9A
>
> On Thu, Oct 07, 2021 at 02:40:29PM +0800, Hao Sun wrote:
> > Hello,
> >
> > This crash can still be triggered repeatedly on the latest kernel.
>
> I asked you three days ago to try a patch and report the results:
>
> https://lore.kernel.org/linux-mm/YVtWhVNFhLbA9+Tl@casper.infradead.org/

Sorry, I missed that.

Here are the results.
Used reproducer: https://paste.ubuntu.com/p/yrYsn4zpcn/
Kernel log *before* applying the patch: https://paste.ubuntu.com/p/WtkFKB6V=
y9/
Kernel log *after* applying the patch: https://paste.ubuntu.com/p/S2VrtDdgg=
p/
Symbolized log: https://paste.ubuntu.com/p/RwXjCXDxB8/

In summary, the reproducer can crash the kernel with the same
backtrace before applying the patch.
After applying the patch, the reproducer program took about 3 minutes
to crash the kernel and the backtrace seems different (RIP points to
create_empty_buffers now).
All the above tests were done on commit 60a9483534ed (Merge tag
'warning-fixes-20211005').

Regards
Hao