Hi Christoph,
Thanks for the patch.
On Tue, Jan 18, 2022 at 8:20 AM Christoph Hellwig <hch@xxxxxx> wrote:
>
> The memory mapped in process_rdma is contiguous, so there is no need
> to loop over bio_add_page. Remove rnbd_bio_map_kern and just open code
> the bio allocation and mapping in the caller.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> drivers/block/rnbd/rnbd-srv-dev.c | 57 -------------------------------
> drivers/block/rnbd/rnbd-srv-dev.h | 5 ---
> drivers/block/rnbd/rnbd-srv.c | 20 ++++++++---
> 3 files changed, 15 insertions(+), 67 deletions(-)
>
> diff --git a/drivers/block/rnbd/rnbd-srv-dev.c b/drivers/block/rnbd/rnbd-srv-dev.c
> index b241a099aeae2..98d3e591a0885 100644
> --- a/drivers/block/rnbd/rnbd-srv-dev.c
> +++ b/drivers/block/rnbd/rnbd-srv-dev.c
> @@ -44,60 +44,3 @@ void rnbd_dev_close(struct rnbd_dev *dev)
> blkdev_put(dev->bdev, dev->blk_open_flags);
> kfree(dev);
> }
> -
> -void rnbd_dev_bi_end_io(struct bio *bio)
> -{
> - struct rnbd_dev_blk_io *io = bio->bi_private;
> -
> - rnbd_endio(io->priv, blk_status_to_errno(bio->bi_status));
> - bio_put(bio);
> -}
> -
> -/**
> - * rnbd_bio_map_kern - map kernel address into bio
> - * @data: pointer to buffer to map
> - * @bs: bio_set to use.
> - * @len: length in bytes
> - * @gfp_mask: allocation flags for bio allocation
> - *
> - * Map the kernel address into a bio suitable for io to a block
> - * device. Returns an error pointer in case of error.
> - */
> -struct bio *rnbd_bio_map_kern(void *data, struct bio_set *bs,
> - unsigned int len, gfp_t gfp_mask)
> -{
> - unsigned long kaddr = (unsigned long)data;
> - unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
> - unsigned long start = kaddr >> PAGE_SHIFT;
> - const int nr_pages = end - start;
> - int offset, i;
> - struct bio *bio;
> -
> - bio = bio_alloc_bioset(gfp_mask, nr_pages, bs);
> - if (!bio)
> - return ERR_PTR(-ENOMEM);
> -
> - offset = offset_in_page(kaddr);
> - for (i = 0; i < nr_pages; i++) {
> - unsigned int bytes = PAGE_SIZE - offset;
> -
> - if (len <= 0)
> - break;
> -
> - if (bytes > len)
> - bytes = len;
> -
> - if (bio_add_page(bio, virt_to_page(data), bytes,
> - offset) < bytes) {
> - /* we don't support partial mappings */
> - bio_put(bio);
> - return ERR_PTR(-EINVAL);
> - }
> -
> - data += bytes;
> - len -= bytes;
> - offset = 0;
> - }
> -
> - return bio;
> -}
> diff --git a/drivers/block/rnbd/rnbd-srv-dev.h b/drivers/block/rnbd/rnbd-srv-dev.h
> index 0eb23850afb95..1a14ece0be726 100644
> --- a/drivers/block/rnbd/rnbd-srv-dev.h
> +++ b/drivers/block/rnbd/rnbd-srv-dev.h
> @@ -41,11 +41,6 @@ void rnbd_dev_close(struct rnbd_dev *dev);
>
> void rnbd_endio(void *priv, int error);
>
> -void rnbd_dev_bi_end_io(struct bio *bio);
> -
> -struct bio *rnbd_bio_map_kern(void *data, struct bio_set *bs,
> - unsigned int len, gfp_t gfp_mask);
> -
> static inline int rnbd_dev_get_max_segs(const struct rnbd_dev *dev)
> {
> return queue_max_segments(bdev_get_queue(dev->bdev));
> diff --git a/drivers/block/rnbd/rnbd-srv.c b/drivers/block/rnbd/rnbd-srv.c
> index 1ee808fc600cf..65c670e96075b 100644
> --- a/drivers/block/rnbd/rnbd-srv.c
> +++ b/drivers/block/rnbd/rnbd-srv.c
> @@ -114,6 +114,14 @@ rnbd_get_sess_dev(int dev_id, struct rnbd_srv_session *srv_sess)
> return sess_dev;
> }
>
> +static void rnbd_dev_bi_end_io(struct bio *bio)
> +{
> + struct rnbd_dev_blk_io *io = bio->bi_private;
> +
> + rnbd_endio(io->priv, blk_status_to_errno(bio->bi_status));
> + bio_put(bio);
> +}
> +
> static int process_rdma(struct rnbd_srv_session *srv_sess,
> struct rtrs_srv_op *id, void *data, u32 datalen,
> const void *usr, size_t usrlen)
> @@ -144,11 +152,11 @@ static int process_rdma(struct rnbd_srv_session *srv_sess,
> priv->sess_dev = sess_dev;
> priv->id = id;
>
> - /* Generate bio with pages pointing to the rdma buffer */
> - bio = rnbd_bio_map_kern(data, sess_dev->rnbd_dev->ibd_bio_set, datalen, GFP_KERNEL);
> - if (IS_ERR(bio)) {
> - err = PTR_ERR(bio);
> - rnbd_srv_err(sess_dev, "Failed to generate bio, err: %d\n", err);
> + bio = bio_alloc_bioset(GFP_KERNEL, 1, sess_dev->rnbd_dev->ibd_bio_set);
> + if (bio_add_page(bio, virt_to_page(data), datalen,
> + offset_in_page(data))) {
this changes lead to IO error all the time, because bio_add_page return len.
We need if (bio_add_page(bio, virt_to_page(data), datalen,
offset_in_page(data)) < datalen)
Thanks!
> + rnbd_srv_err(sess_dev, "Failed to map data to bio\n");
> + err = -EINVAL;
> goto sess_dev_put;
> }
>
> @@ -170,6 +178,8 @@ static int process_rdma(struct rnbd_srv_session *srv_sess,
>
> return 0;
>
> +bio_put:
> + bio_put(bio);
> sess_dev_put:
> rnbd_put_sess_dev(sess_dev);
> err:
> --
> 2.30.2
>
