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From:   Stefano Garzarella <sgarzare@redhat.com>
Date:   Mon, 21 Feb 2022 12:49:45 +0100
Message-ID: <CAGxU2F6+m4pa7gzqvFL1OGLCc8sFDjRwhXZruFi41PQMs-XRew@mail.gmail.com>
Subject: Re: [PATCH] block: clear iocb->private in blkdev_bio_end_io_async()
To:     Jens Axboe <axboe@kernel.dk>,
        Pavel Begunkov <asml.silence@gmail.com>
Cc:     kernel list <linux-kernel@vger.kernel.org>,
        linux-block@vger.kernel.org
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Gentle ping :-)


On Fri, Feb 11, 2022 at 10:01 AM Stefano Garzarella <sgarzare@redhat.com> wrote:
>
> iocb_bio_iopoll() expects iocb->private to be cleared before
> releasing the bio.
>
> We already do this in blkdev_bio_end_io(), but we forgot in the
> recently added blkdev_bio_end_io_async().
>
> Fixes: 54a88eb838d3 ("block: add single bio async direct IO helper")
> Cc: asml.silence@gmail.com
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
> I haven't seen a failure, I was just reading the code to understand iopoll,
> so IIUC we should clean iocb->private in blkdev_bio_end_io_async().
>
> Thanks,
> Stefano
> ---
>  block/fops.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/block/fops.c b/block/fops.c
> index 4f59e0f5bf30..a18e7fbd97b8 100644
> --- a/block/fops.c
> +++ b/block/fops.c
> @@ -289,6 +289,8 @@ static void blkdev_bio_end_io_async(struct bio *bio)
>         struct kiocb *iocb = dio->iocb;
>         ssize_t ret;
>
> +       WRITE_ONCE(iocb->private, NULL);
> +
>         if (likely(!bio->bi_status)) {
>                 ret = dio->size;
>                 iocb->ki_pos += ret;
> --
> 2.34.1
>