Commit 7e26cb69 authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

ublk: rely on ->canceling for dealing with ublk_nosrv_dev_should_queue_io 



Now ublk deals with ublk_nosrv_dev_should_queue_io() by keeping request
queue as quiesced. This way is fragile because queue quiesce crosses syscalls
or process contexts.

Switch to rely on ubq->canceling for dealing with
ublk_nosrv_dev_should_queue_io(), because it has been used for this purpose
during io_uring context exiting, and it can be reused before recovering too.
In ublk_queue_rq(), the request will be added to requeue list without
kicking off requeue in case of ubq->canceling, and finally requests added in
requeue list will be dispatched from either ublk_stop_dev() or
ublk_ctrl_end_recovery().

Meantime we have to move reset of ubq->canceling from ublk_ctrl_start_recovery()
to ublk_ctrl_end_recovery(), when IO handling can be recovered completely.

Then blk_mq_quiesce_queue() and blk_mq_unquiesce_queue() are always used
in same context.

Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Reviewed-by: default avatarUday Shankar <ushankar@purestorage.com>
Link: https://lore.kernel.org/r/20250416035444.99569-4-ming.lei@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 00b3b0d7

drivers/block/ublk_drv.c

+17 −14
Original line number Diff line number Diff line
@@ -1734,13 +1734,19 @@ static void ublk_wait_tagset_rqs_idle(struct ublk_device *ub) 


static void __ublk_quiesce_dev(struct ublk_device *ub)

{

	int i;



	pr_devel("%s: quiesce ub: dev_id %d state %s\n",

			__func__, ub->dev_info.dev_id,

			ub->dev_info.state == UBLK_S_DEV_LIVE ?

			"LIVE" : "QUIESCED");

	blk_mq_quiesce_queue(ub->ub_disk->queue);

	/* mark every queue as canceling */

	for (i = 0; i < ub->dev_info.nr_hw_queues; i++)

		ublk_get_queue(ub, i)->canceling = true;

	ublk_wait_tagset_rqs_idle(ub);

	ub->dev_info.state = UBLK_S_DEV_QUIESCED;

	blk_mq_unquiesce_queue(ub->ub_disk->queue);

}



static void ublk_force_abort_dev(struct ublk_device *ub)
@@ -2961,7 +2967,6 @@ static void ublk_queue_reinit(struct ublk_device *ub, struct ublk_queue *ubq) 
	/* We have to reset it to NULL, otherwise ub won't accept new FETCH_REQ */

	ubq->ubq_daemon = NULL;

	ubq->timeout = false;

	ubq->canceling = false;



	for (i = 0; i < ubq->q_depth; i++) {

		struct ublk_io *io = &ubq->ios[i];
@@ -3048,20 +3053,18 @@ static int ublk_ctrl_end_recovery(struct ublk_device *ub, 
	pr_devel("%s: new ublksrv_pid %d, dev id %d\n",

			__func__, ublksrv_pid, header->dev_id);



	if (ublk_nosrv_dev_should_queue_io(ub)) {

		ub->dev_info.state = UBLK_S_DEV_LIVE;

		blk_mq_unquiesce_queue(ub->ub_disk->queue);

		pr_devel("%s: queue unquiesced, dev id %d.\n",

				__func__, header->dev_id);

		blk_mq_kick_requeue_list(ub->ub_disk->queue);

	} else {

	blk_mq_quiesce_queue(ub->ub_disk->queue);

	ub->dev_info.state = UBLK_S_DEV_LIVE;

	for (i = 0; i < ub->dev_info.nr_hw_queues; i++) {

			ublk_get_queue(ub, i)->fail_io = false;

		struct ublk_queue *ubq = ublk_get_queue(ub, i);



		ubq->canceling = false;

		ubq->fail_io = false;

	}

	blk_mq_unquiesce_queue(ub->ub_disk->queue);

	}

	pr_devel("%s: queue unquiesced, dev id %d.\n",

			__func__, header->dev_id);

	blk_mq_kick_requeue_list(ub->ub_disk->queue);



	ret = 0;

 out_unlock: