lkml.org 
[lkml]   [2021]   [Jul]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [syzbot] possible deadlock in loop_add
From
Date
On 16/7/21 7:00 am, Miquel Raynal wrote:
> Hello,
>
> Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com> wrote on Mon, 12 Jul
> 2021 16:29:16 +0800:
>
>> On 12/7/21 1:27 pm, Christoph Hellwig wrote:
>>> On Sat, Jul 10, 2021 at 09:16:38PM +0800, Hillf Danton wrote:
>>>> To break the lock chain, un/register blkdev without mtd_table_mutex held.
>>>
>>> Yes, Desmond Cheong Zhi Xi sent pretty much the same patch on June 18th
>>> (mtd: break circular locks in register_mtd_blktrans), but it did not get
>>> picked up.
>>>
>>
>> I believe Miquèl was waiting for -rc1 to apply it.
>
> Indeed, I already applied it but did not advertise yet.
>

Thanks Miquèl!

>>
>> But taking a closer look, although the fix for the register path is the same, Hillf Danton's proposed patch additionally avoids inverting the lock hierarchy on the unregister path. So I believe this new patch should be more robust.
>
> We can definitely do this in two steps if you want.
>

Sounds good, I'll prepare a patch with Hillf's suggestion for the
unregister path.

> Thanks,
> Miquèl
>

\
 
 \ /
  Last update: 2021-07-17 11:43    [W:0.049 / U:0.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site