On Wed, May 04, 2022 at 09:23:39AM -0700, Christoph Hellwig wrote:
> Allow the file system to keep state for all iterations. For now only
> wire it up for direct I/O as there is an immediate need for it there.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> fs/iomap/direct-io.c | 8 ++++++++
> include/linux/iomap.h | 1 +
> 2 files changed, 9 insertions(+)
>
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 15929690d89e3..355abe2eacc6a 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -520,6 +520,14 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> dio->submit.waiter = current;
> dio->submit.poll_bio = NULL;
>
> + /*
> + * Transfer the private data that was passed by the caller to the
> + * iomap_iter, and clear it in the iocb, as iocb->private will be
> + * used for polled bio completion later.
> + */
> + iomi.private = iocb->private;
> + WRITE_ONCE(iocb->private, NULL);
Do we need to transfer it back after the bio completes? Or is it a
feature that iocb->private changes to the bio?
--D
> +
> if (iov_iter_rw(iter) == READ) {
> if (iomi.pos >= dio->i_size)
> goto out_free_dio;
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index a5483020dad41..109c055865f73 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -188,6 +188,7 @@ struct iomap_iter {
> unsigned flags;
> struct iomap iomap;
> struct iomap srcmap;
> + void *private;
> };
>
> int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops);
> --
> 2.30.2
>
