Commit b4e1353f authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

ublk: simplify aborting request 



Now ublk_abort_queue() is run exclusively with ublk_queue_rq() and the
ubq_daemon task, so simplify aborting request:

- set UBLK_IO_FLAG_ABORTED in ublk_abort_queue() just for aborting
this request

- abort request in ublk_queue_rq() if ubq->canceling is set

Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20231009093324.957829-8-ming.lei@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 216c8f5e

drivers/block/ublk_drv.c

+11 −30
Original line number Diff line number Diff line
@@ -1084,14 +1084,11 @@ static void __ublk_fail_req(struct ublk_queue *ubq, struct ublk_io *io, 
{

	WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE);



	if (!(io->flags & UBLK_IO_FLAG_ABORTED)) {

		io->flags |= UBLK_IO_FLAG_ABORTED;

	if (ublk_queue_can_use_recovery_reissue(ubq))

		blk_mq_requeue_request(req, false);

	else

		ublk_put_req_ref(ubq, req);

}

}



static void ubq_complete_io_cmd(struct ublk_io *io, int res,

				unsigned issue_flags)
@@ -1231,27 +1228,10 @@ static void ublk_rq_task_work_cb(struct io_uring_cmd *cmd, unsigned issue_flags) 
static void ublk_queue_cmd(struct ublk_queue *ubq, struct request *rq)

{

	struct ublk_rq_data *data = blk_mq_rq_to_pdu(rq);

	struct ublk_io *io;



	if (!llist_add(&data->node, &ubq->io_cmds))

		return;

	if (llist_add(&data->node, &ubq->io_cmds)) {

		struct ublk_io *io = &ubq->ios[rq->tag];



	io = &ubq->ios[rq->tag];

	/*

	 * If the check pass, we know that this is a re-issued request aborted

	 * previously in cancel fn because the ubq_daemon(cmd's task) is

	 * PF_EXITING. We cannot call io_uring_cmd_complete_in_task() anymore

	 * because this ioucmd's io_uring context may be freed now if no inflight

	 * ioucmd exists. Otherwise we may cause null-deref in ctx->fallback_work.

	 *

	 * Note: cancel fn sets UBLK_IO_FLAG_ABORTED and ends this request(releasing

	 * the tag). Then the request is re-started(allocating the tag) and we are here.

	 * Since releasing/allocating a tag implies smp_mb(), finding UBLK_IO_FLAG_ABORTED

	 * guarantees that here is a re-issued request aborted previously.

	 */

	if (unlikely(io->flags & UBLK_IO_FLAG_ABORTED)) {

		ublk_abort_io_cmds(ubq);

	} else {

		io_uring_cmd_complete_in_task(io->cmd, ublk_rq_task_work_cb);

	}

}
@@ -1321,13 +1301,12 @@ static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx, 
	if (ublk_queue_can_use_recovery(ubq) && unlikely(ubq->force_abort))

		return BLK_STS_IOERR;



	blk_mq_start_request(bd->rq);



	if (unlikely(ubq->canceling)) {

		__ublk_abort_rq(ubq, rq);

		return BLK_STS_OK;

	}



	blk_mq_start_request(bd->rq);

	ublk_queue_cmd(ubq, rq);



	return BLK_STS_OK;
@@ -1450,11 +1429,13 @@ static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq) 
			 * will do it

			 */

			rq = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], i);

			if (rq)

			if (rq && blk_mq_request_started(rq)) {

				io->flags |= UBLK_IO_FLAG_ABORTED;

				__ublk_fail_req(ubq, io, rq);

			}

		}

	}

}



static bool ublk_abort_requests(struct ublk_device *ub, struct ublk_queue *ubq)

{
@@ -1535,7 +1516,7 @@ static void ublk_uring_cmd_cancel_fn(struct io_uring_cmd *cmd, 


	io = &ubq->ios[pdu->tag];

	WARN_ON_ONCE(io->cmd != cmd);

	ublk_cancel_cmd(ubq, &ubq->ios[pdu->tag], issue_flags);

	ublk_cancel_cmd(ubq, io, issue_flags);



	if (need_schedule) {

		if (ublk_can_use_recovery(ub))