> On 14 May 2021, at 14:43, Martin Pieuchot <[email protected]> wrote:
>
> On 13/05/21(Thu) 14:50, Vitaliy Makkoveev wrote:
>> On Thu, May 13, 2021 at 01:15:05PM +0200, Hrvoje Popovski wrote:
>>> On 13.5.2021. 1:25, Vitaliy Makkoveev wrote:
>>>> It seems this lock order issue is not parallel diff specific.
>>>
>>>
>>>
>>> Yes, you are right ... it seemed familiar but i couldn't reproduce it
>>> on lapc trunk or without this diff so i thought that parallel diff is
>>> one to blame ..
>>>
>>>
>>> sorry for noise ..
>>>
>>
>> Timeout thread and interface destroy thread are both serialized by
>> kernel lock so it's hard to catch this issue. So your report is
>> useful :)
>
> The use of the NET_LOCK() in *clone_destroy() is problematic. tpmr(4)
> has a similar problem as reported by Hrvoje in a different thread. I
> don't know what it is serializing, hopefully David can tell us more.
>
It serializes detach hook and clone_detach. Detach hooks are executed
with netlock held. Unfortunately this problem is much complicated,
and we can’t just introduce new lock to solve it because this will
introduce lock order issue.
