On Fri, Feb 11, 2022 at 10:01:36AM +0100, Stefano Garzarella 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
But also iomap_dio_bio_end_io().
> recently added blkdev_bio_end_io_async().
>
> Fixes: 54a88eb838d3 ("block: add single bio async direct IO helper")
> Cc: asml.silence@xxxxxxxxx
> Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
> ---
> 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);
It might cause race in case of concurrent polling on same queue without
clearing iocb->private, so looks fine:
Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>
Thanks,
Ming
