From: Jens Axboe <axboe@kernel.dk>
To: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Cc: linux-block@vger.kernel.org
Subject: Re: [RFC 1/2] io_uring: clear req->result always before issuing a read/write request
Date: Wed, 15 Jan 2020 21:34:50 -0700 [thread overview]
Message-ID: <4e20c457-da35-6433-dfd2-82877e7ccc6a@kernel.dk> (raw)
In-Reply-To: <1579142266-64789-2-git-send-email-bijan.mottahedeh@oracle.com>
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
next prev parent reply other threads:[~2020-01-16 4:34 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-16 2:37 [RFC 0/2] Fixes for fio io_uring polled mode test failures Bijan Mottahedeh
2020-01-16 2:37 ` [RFC 1/2] io_uring: clear req->result always before issuing a read/write request Bijan Mottahedeh
2020-01-16 4:34 ` Jens Axboe [this message]
2020-01-16 2:37 ` [RFC 2/2] io_uring: acquire ctx->uring_lock before calling io_issue_sqe() Bijan Mottahedeh
2020-01-16 4:34 ` Jens Axboe
2020-01-16 4:42 ` Jens Axboe
2020-01-16 16:22 ` Jens Axboe
2020-01-16 19:08 ` Bijan Mottahedeh
2020-01-16 20:02 ` Jens Axboe
2020-01-16 21:04 ` Bijan Mottahedeh
2020-01-16 21:26 ` Jens Axboe
2020-01-28 20:34 ` Bijan Mottahedeh
2020-01-28 23:37 ` Jens Axboe
2020-01-28 23:49 ` Bijan Mottahedeh
2020-01-28 23:52 ` Jens Axboe
2020-01-31 3:36 ` Bijan Mottahedeh
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