Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <68b9650e-bef2-69e2-ab5e-8aaddaf46cfe@huawei.com>
 <CAO9xwp12E1wjErfX-Ef6+OKnme_ENOx22Hh=44g9cLn7aBr3-w@mail.gmail.com> <c4c16548-1f37-a63e-de38-de5812bcc97e@huawei.com>
In-Reply-To: <c4c16548-1f37-a63e-de38-de5812bcc97e@huawei.com>
From:   Mauricio Oliveira <mauricio.oliveira@canonical.com>
Date:   Thu, 19 Nov 2020 10:12:52 -0300
Message-ID: <CAO9xwp37T_pDohXYOpHhb-KhDYUBEMR0qDN0NJvCLRUoG3CK2Q@mail.gmail.com>
Subject: Re: [Bug report] journal data mode trigger panic in jbd2_journal_commit_transaction
To:     yangerkun <yangerkun@huawei.com>
Cc:     "Theodore Y . Ts'o" <tytso@mit.edu>, adilger.kernel@dilger.ca,
        Jan Kara <jack@suse.cz>, linux-ext4@vger.kernel.org,
        "zhangyi (F)" <yi.zhang@huawei.com>, Hou Tao <houtao1@huawei.com>,
        zhangxiaoxu5@huawei.com, Ye Bin <yebin10@huawei.com>,
        hejie3@huawei.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 8BIT
Precedence: bulk

On Thu, Nov 19, 2020 at 1:25 AM yangerkun <yangerkun@huawei.com> wrote:
>
>
>
> 在 2020/11/16 21:50, Mauricio Oliveira 写道:
> > Hi Kun,
> >
> > On Sat, Nov 14, 2020 at 5:18 AM yangerkun <yangerkun@huawei.com> wrote:
> >> While using ext4 with data=journal(3.10 kernel), we meet a problem that
> >> we think may never happend...
> > [...]
> >
> > Could you please confirm you mean 5.10-rc* kernel instead of 3.10?
> > (It seems so as you mention a recent commit below.)  Thanks!
> >
> >> For now, what I have seen that can dirty buffer directly is
> >> ext4_page_mkwrite(64a9f1449950 ("ext4: data=journal: fixes for
> >> ext4_page_mkwrite()")), and runing ext4_punch_hole with keep_size
> >> /ext4_page_mkwrite parallel can trigger above warning easily.
> > [...]
> >
> >
>
> Hi,
>
> Sorry for the long delay reply... And thanks a lot for your advise! The
> bug trigger with a very low probability. So won't trigger with 5.10 can
> not prove no bug exist in 5.10.
>

No worries, and thanks for following up.
So I understand that the bug report was indeed on 3.10, and 5.10-rcN
is not yet confirmed.

> Google a lot and notice that someone before has report the same bug[1].
> '3b136499e906 ("ext4: fix data corruption in data=journal mode")' seems
> fix the problem. I will try to understand this, and give a analysis
> about how to reproduce it!

Cool, thanks!

> Thanks,
> Kun.


-- 
Mauricio Faria de Oliveira