Re: [PATCH] io_uring: Fix LINK_TIMEOUT checks

[Jens Axboe <axboe@kernel.dk>]

On 11/14/19 7:36 PM, Jens Axboe wrote:
> On 11/14/19 5:12 PM, Jens Axboe wrote:
>> On 11/14/19 2:25 PM, Jens Axboe wrote:
>>> On 11/14/19 2:20 PM, Pavel Begunkov wrote:
>>>> If IORING_OP_LINK_TIMEOUT request is a head of a link or an individual
>>>> request, pass it further through the submission path, where it will
>>>> eventually fail in __io_submit_sqe(). So respecting links and drains.
>>>>
>>>> The case, which is really need to be checked, is if a
>>>> IORING_OP_LINK_TIMEOUT request is 3rd or later in a link, that is
>>>> invalid from the user API perspective (judging by the code). Moreover,
>>>> put/free and friends will try to io_link_cancel_timeout() such request,
>>>> even though it wasn't initialised.
>>>
>>> Care to add a test case for these to liburings test/link-timeout.c?
>>
>> Wrote some test cases, I think that io_req_link_next() is just wrong.
>> The below should correct it. We shouldn't loop here at all, just find
>> the first one. That'll start that guy, sequence will continue, etc.
> 
> Well that was crap, I sent an earlier unfinished version. Here's the
> right one:

I think the only thing missing after this is handling multiple linked
timeouts in a sequence. I'll do that now.

-- 
Jens Axboe