Re: INFO: task hung in generic_file_write_iter

From: Tetsuo Handa
Date: Mon Aug 20 2018 - 10:13:28 EST


On 2018/08/06 20:56, Tetsuo Handa wrote:
> On 2018/08/06 19:09, Jan Kara wrote:
>> Looks like some kind of a race where device block size gets changed while
>> getblk() runs (and creates buffers for underlying page). I don't have time
>> to nail it down at this moment can have a look into it later unless someone
>> beats me to it.
>>
>
> It seems that loop device is relevant to this problem.

Speak of loop device, I'm waiting for Jens for three months
http://lkml.kernel.org/r/1527297408-4428-1-git-send-email-penguin-kernel@xxxxxxxxxxxxxxxxxxx
but Jens is too busy to come up with an alternative. Since that is a big patch, I wish we can
start testing that patch before Jan starts writing a patch for fixing getblk() race problem.