linux-kernel - Re: INFO: task hung in __floppy_read_block

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Message-ID: <CANX2M5YxE31gSU804jm6U4T6uTeCTjgk1gfHM+ockpjHnXfDrw@mail.gmail.com>
Date:   Mon, 1 Aug 2022 22:04:46 -0700
From:   Dipanjan Das <mail.dipanjan.das@...il.com>
To:     Willy Tarreau <w@....eu>
Cc:     Lukas Bulwahn <lukas.bulwahn@...il.com>,
        Denis Efremov <efremov@...ux.com>,
        Jens Axboe <axboe@...nel.dk>, linux-block@...r.kernel.org,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        syzkaller <syzkaller@...glegroups.com>,
        fleischermarius@...glemail.com, its.priyanka.bose@...il.com
Subject: Re: INFO: task hung in __floppy_read_block_0

On Sun, Jul 31, 2022 at 2:53 AM Willy Tarreau <w@....eu> wrote:
>
> Thus I'm a bit confused about what to look for. It's very likely that
> there are still bugs left in this driver, but trying to identify them
> and to validate a fix will be difficult if they cannot be reproduced.
> Maybe they only happen under emulation due to timing issues.
>
> As such, any hint about the exact setup and how long to wait to get
> the error would be much appreciated.

We can confirm that we were able to trigger the issue on the latest
5.19 (commit: 3d7cb6b04c3f3115719235cc6866b10326de34cd) with the
C-repro within a VM. We use this:
https://syzkaller.appspot.com/text?tag=KernelConfig&x=cd73026ceaed1402
 config to build the kernel. The issue triggers after around 143
seconds. For all the five times we tried, we were able to reproduce
the issue deterministically every time. Please let us know if you need
any other information.

-- 
Thanks and Regards,

Dipanjan