On Sat, Apr 26, 2025 at 10:58:00PM -0600, Caleb Sander Mateos wrote:
> In preparation for calling it from outside ublk_dispatch_req(), factor
> out the code responsible for setting up an incoming ublk I/O request.
>
> Signed-off-by: Caleb Sander Mateos <csander@xxxxxxxxxxxxxxx>
> ---
> drivers/block/ublk_drv.c | 53 ++++++++++++++++++++++------------------
> 1 file changed, 29 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> index 01fc92051754..90a38a82f8cc 100644
> --- a/drivers/block/ublk_drv.c
> +++ b/drivers/block/ublk_drv.c
> @@ -1151,17 +1151,44 @@ static inline void __ublk_abort_rq(struct ublk_queue *ubq,
> blk_mq_requeue_request(rq, false);
> else
> blk_mq_end_request(rq, BLK_STS_IOERR);
> }
>
> +static void ublk_start_io(struct ublk_queue *ubq, struct request *req,
> + struct ublk_io *io)
> +{
> + unsigned mapped_bytes = ublk_map_io(ubq, req, io);
> +
> + /* partially mapped, update io descriptor */
> + if (unlikely(mapped_bytes != blk_rq_bytes(req))) {
> + /*
> + * Nothing mapped, retry until we succeed.
> + *
> + * We may never succeed in mapping any bytes here because
> + * of OOM. TODO: reserve one buffer with single page pinned
> + * for providing forward progress guarantee.
> + */
> + if (unlikely(!mapped_bytes)) {
> + blk_mq_requeue_request(req, false);
> + blk_mq_delay_kick_requeue_list(req->q,
> + UBLK_REQUEUE_DELAY_MS);
> + return;
> + }
> +
> + ublk_get_iod(ubq, req->tag)->nr_sectors =
> + mapped_bytes >> 9;
> + }
> +
> + ublk_init_req_ref(ubq, req);
> +}
> +
> static void ublk_dispatch_req(struct ublk_queue *ubq,
> struct request *req,
> unsigned int issue_flags)
> {
> int tag = req->tag;
> struct ublk_io *io = &ubq->ios[tag];
> - unsigned int mapped_bytes;
>
> pr_devel("%s: complete: qid %d tag %d io_flags %x addr %llx\n",
> __func__, ubq->q_id, req->tag, io->flags,
> ublk_get_iod(ubq, req->tag)->addr);
>
> @@ -1204,33 +1231,11 @@ static void ublk_dispatch_req(struct ublk_queue *ubq,
> pr_devel("%s: update iod->addr: qid %d tag %d io_flags %x addr %llx\n",
> __func__, ubq->q_id, req->tag, io->flags,
> ublk_get_iod(ubq, req->tag)->addr);
> }
>
> - mapped_bytes = ublk_map_io(ubq, req, io);
> -
> - /* partially mapped, update io descriptor */
> - if (unlikely(mapped_bytes != blk_rq_bytes(req))) {
> - /*
> - * Nothing mapped, retry until we succeed.
> - *
> - * We may never succeed in mapping any bytes here because
> - * of OOM. TODO: reserve one buffer with single page pinned
> - * for providing forward progress guarantee.
> - */
> - if (unlikely(!mapped_bytes)) {
> - blk_mq_requeue_request(req, false);
> - blk_mq_delay_kick_requeue_list(req->q,
> - UBLK_REQUEUE_DELAY_MS);
> - return;
> - }
Here it needs to break ublk_dispatch_req() for not completing the
uring_cmd, however ublk_start_io() can't support it.
Thanks,
Ming
