Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) client-ip=2620:137:e000::3:6;
Message-ID: <673230ba-61d7-4c7f-aaf4-d5e2fc54944e@sapience.com>
Date:   Thu, 7 Dec 2023 14:27:49 -0500
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: md raid6 oops in 6.6.4 stable
Content-Language: en-US
To:     Song Liu <song@kernel.org>
Cc:     Guoqing Jiang <guoqing.jiang@linux.dev>,
        Bagas Sanjaya <bagasdotme@gmail.com>, snitzer@kernel.org,
        yukuai3@huawei.com, axboe@kernel.dk, mpatocka@redhat.com,
        heinzm@redhat.com,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux RAID <linux-raid@vger.kernel.org>,
        Linux Regressions <regressions@lists.linux.dev>,
        Bhanu Victor DiCara <00bvd0+linux@gmail.com>,
        Xiao Ni <xni@redhat.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
References: <6e6816dd-2ec5-4bca-9558-60cfde46ef8c@sapience.com>
 <ZXHJEkwIJ5zKTMjV@archie.me>
 <be56b5df-fef8-4dbe-bb98-f6370a692d6e@sapience.com>
 <714b22c7-b8dd-008d-a1ea-a184dc8ec1cf@linux.dev>
 <c866bcfa-85cc-44fb-9b54-bb4840f588e6@sapience.com>
 <CAPhsuW4Cu5DdxZtZDbwLJ85oUpN9prS78Rr9UeFtgx88OGxUcA@mail.gmail.com>
From:   Genes Lists <lists@sapience.com>
In-Reply-To: <CAPhsuW4Cu5DdxZtZDbwLJ85oUpN9prS78Rr9UeFtgx88OGxUcA@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 12/7/23 12:37, Song Liu wrote:
...
>    kernel:  md_end_clone_io+0x75/0xa0     <<< change in md_end_clone_io
> 
> The commit only changes how we update bi_status. But bi_status was not
> used/checked at all between md_end_clone_io and the trap (lock cmpxchg).
> Did I miss something?
> 
> Given the issue takes very long to reproduce. Maybe we have the issue
> before 6.6.4?
> 
> Thanks,
> Song

Thanks for clarifying that point.

In meantime I rebooted server (shutdown was a struggle) - finally I 
fsck'd the filesystem (ext4) sitting on the raid6 - and manually ran the 
triggering rsync. This of course completed normally. That's either good 
or bad depending on your perspective :)

If I can get it to crash again, I will either start a git bisect (from 
6.6.3) or see if 6.7rc4 shows same issue.

thanks,

gene