[PATCH 2/3] io_uring/rw: handle -EAGAIN retry at IO completion time

[Jens Axboe]

On 3/5/25 9:57 AM, John Garry wrote:
> On 04/03/2025 18:10, John Garry wrote:
> 
> +
> 
>> On 09/01/2025 18:15, Jens Axboe wrote:
>>> Rather than try and have io_read/io_write turn REQ_F_REISSUE into
>>> -EAGAIN, catch the REQ_F_REISSUE when the request is otherwise
>>> considered as done. This is saner as we know this isn't happening
>>> during an actual submission, and it removes the need to randomly
>>> check REQ_F_REISSUE after read/write submission.
>>>
>>> If REQ_F_REISSUE is set, __io_submit_flush_completions() will skip over
>>> this request in terms of posting a CQE, and the regular request
>>> cleaning will ensure that it gets reissued via io-wq.
>>>
>>> Signed-off-by: Jens Axboe <axboe at kernel.dk>
>>
> 
> Further info, I can easily recreate this on latest block/io_uring-6.14 on real NVMe HW:

Thanks, I'll take a look!

-- 
Jens Axboe