Re: [PATCH 1/1] io_uring: fix leaks on IOPOLL and CQE_SKIP

[Jens Axboe <axboe@kernel.dk>]

On 4/12/22 10:24 AM, Pavel Begunkov wrote:
> If all completed requests in io_do_iopoll() were marked with
> REQ_F_CQE_SKIP, we'll not only skip CQE posting but also
> io_free_batch_list() leaking memory and resources.
> 
> Move @nr_events increment before REQ_F_CQE_SKIP check. We'll potentially
> return the value greater than the real one, but iopolling will deal with
> it and the userspace will re-iopoll if needed. In anyway, I don't think
> there are many use cases for REQ_F_CQE_SKIP + IOPOLL.

Ah good catch - yes probably not much practical concern, as the lack of
ordering for file IO means that CQE_SKIP isn't really useful for that
scenario.

-- 
Jens Axboe