From: Nadav Amit <nadav.amit@gmail.com>
To: Jens Axboe <axboe@kernel.dk>, Pavel Begunkov <asml.silence@gmail.com>
Cc: io-uring@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: io-uring: KASAN failure, presumably REQ_F_REISSUE issue
Date: Sat, 11 Sep 2021 21:43:18 -0700 [thread overview]
Message-ID: <825AB372-93CE-43C0-8947-EAB819547494@gmail.com> (raw)
In-Reply-To: <2C3AECED-1915-4080-B143-5BA4D76FB5CD@gmail.com>
> On Sep 11, 2021, at 7:34 PM, Nadav Amit <nadav.amit@gmail.com> wrote:
>
> Hello Jens (& Pavel),
>
> I hope you are having a nice weekend. I ran into a KASAN failure in io-uring
> which I think is not "my fault".
Small correction of myself (beside the subject):
>
> I believe the issue is related to the handling of REQ_F_REISSUE and
> specifically to commit 230d50d448acb ("io_uring: move reissue into regular IO
> path"). There seems to be a race between io_write()/io_read()
> and __io_complete_rw()/kiocb_done().
>
> __io_complete_rw() sets REQ_F_REIUSSE:
>
> if ((res == -EAGAIN || res == -EOPNOTSUPP) &&
> io_rw_should_reissue(req)) {
> req->flags |= REQ_F_REISSUE;
> return;
> }
The race only appears to be with __io_complete_rw(), not kiocb_done().
next prev parent reply other threads:[~2021-09-12 4:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-12 2:34 io-uring: KASAN failure, presumably Nadav Amit
2021-09-12 4:43 ` Nadav Amit [this message]
2021-09-12 13:00 ` Jens Axboe
2021-09-12 18:15 ` Jens Axboe
2021-09-12 18:21 ` Nadav Amit
2021-09-12 18:24 ` Jens Axboe
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