Re: [PATCH 1/3] 9p/net: implement asynchronous rpc

From: Tomas Bortoli
Date: Mon Dec 17 2018 - 17:15:01 EST


On 12/17/18 12:01 PM, Dominique Martinet wrote:
> Tomas Bortoli wrote on Mon, Dec 17, 2018:
>> sorry for the delay, I've been quite busy these days.
>
> No problem.
>
>> The patches looks good to me and should indeed speed up the code a bit.
>> I quickly tested them against Syzkaller tuned for the 9p subsystem and
>> everything seems fine.
>
> Thanks, can I add your Reviewed-by on all three?
>

Sure, FWIW.

>> And by the way, which refcount races?
>
> There's a problem with trans_fd read_work and cancelled callback; I'm
> not so sure about refcount but we can definitely get double list_del
> as we're not checking the status. I think when we incorrectly remove
> from the list we also mismanage the refcount, but honestly need to
> test..
>

Yeah, definitely it needs to check the status. Btw, if a double
list_del happens the kernel should crash.