Re: [RFC 1/2] io_uring: clear req->result always before issuing a read/write request

[Jens Axboe <axboe@kernel.dk>]

On 1/15/20 7:37 PM, Bijan Mottahedeh wrote:
> req->result is cleared when io_issue_sqe() calls io_read/write_pre()
> routines.  Those routines however are not called when the sqe
> argument is NULL, which is the case when io_issue_sqe() is called from
> io_wq_submit_work().  io_issue_sqe() may then examine a stale result if
> a polled request had previously failed with -EAGAIN:
> 
>         if (ctx->flags & IORING_SETUP_IOPOLL) {
>                 if (req->result == -EAGAIN)
>                         return -EAGAIN;
> 
>                 io_iopoll_req_issued(req);
>         }
> 
> and in turn cause a subsequently completed request to be re-issued in
> io_wq_submit_work().

Looks good, thanks.

-- 
Jens Axboe