Re: [PATCH V5 3/7] ublk_drv: requeue rqs with recovery feature enabled

Ming Lei
2022-09-23T03:07:41Z

On Thu, Sep 22, 2022 at 02:17:30PM +0800, ZiyangZhang wrote:
> With recovery feature enabled, in ublk_queue_rq or task work
> (in exit_task_work or fallback wq), we requeue rqs instead of
> ending(aborting) them. Besides, No matter recovery feature is enabled
> or disabled, we schedule monitor_work immediately.
>
> Signed-off-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com>
> ---
> drivers/block/ublk_drv.c | 25 +++++++++++++++++++++++--
> 1 file changed, 23 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> index 05bfbaa49696..a1cbcc5e9285 100644
> --- a/drivers/block/ublk_drv.c
> +++ b/drivers/block/ublk_drv.c
> @@ -655,6 +655,16 @@ static void ubq_complete_io_cmd(struct ublk_io *io, int res)
>
> #define UBLK_REQUEUE_DELAY_MS 3
>
> +static inline void __ublk_abort_rq_in_task_work(struct ublk_queue *ubq,
> + struct request *rq)
> +{
> + /* We cannot process this rq so just requeue it. */
> + if (ublk_queue_can_use_recovery(ubq))
> + blk_mq_requeue_request(rq, false);
> + else
> + blk_mq_end_request(rq, BLK_STS_IOERR);
> +}

__ublk_abort_rq_in_task_work() can be renamed as __ublk_abort_rq(), then
be reused for the user of ublk_queue_rq().

> +
> static inline void __ublk_rq_task_work(struct request *req)
> {
> struct ublk_queue *ubq = req->mq_hctx->driver_data;
> @@ -677,7 +687,7 @@ static inline void __ublk_rq_task_work(struct request *req)
> * (2) current->flags & PF_EXITING.
> */
> if (unlikely(current != ubq->ubq_daemon || current->flags & PF_EXITING)) {
> - blk_mq_end_request(req, BLK_STS_IOERR);
> + __ublk_abort_rq_in_task_work(ubq, req);
> mod_delayed_work(system_wq, &ub->monitor_work, 0);
> return;
> }
> @@ -752,6 +762,17 @@ static void ublk_rq_task_work_fn(struct callback_head *work)
> __ublk_rq_task_work(req);
> }
>
> +static inline blk_status_t __ublk_abort_rq(struct ublk_queue *ubq,
> + struct request *rq)
> +{
> + /* We cannot process this rq so just requeue it. */
> + if (ublk_queue_can_use_recovery(ubq)) {
> + blk_mq_requeue_request(rq, false);
> + return BLK_STS_OK;
> + }
> + return BLK_STS_IOERR;
> +}

The above helper isn't needed.

> +
> static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx,
> const struct blk_mq_queue_data *bd)
> {
> @@ -769,7 +790,7 @@ static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx,
> if (unlikely(ubq_daemon_is_dying(ubq))) {
> fail:
> mod_delayed_work(system_wq, &ubq->dev->monitor_work, 0);
> - return BLK_STS_IOERR;
> + return __ublk_abort_rq(ubq, rq);

Then you can call __ublk_abort_rq(), and return BLK_STS_OK.

thanks.
Ming