Commit a0d41dc1 authored by ZiyangZhang's avatar ZiyangZhang Committed by Jens Axboe
Browse files

ublk_drv: support UBLK_F_USER_RECOVERY_REISSUE 



UBLK_F_USER_RECOVERY_REISSUE implies that:
With a dying ubq_daemon, ublk_drv let monitor_work requeues rq issued to
userspace(ublksrv) before the ubq_daemon is dying.

UBLK_F_USER_RECOVERY_REISSUE is designed for backends which:
(1) tolerate double-write since ublk_drv may issue the same rq
    twice.
(2) does not let frontend users get I/O error, such as read-only FS
    and VM backend.

Signed-off-by: default avatarZiyangZhang <ZiyangZhang@linux.alibaba.com>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220923153919.44078-6-ZiyangZhang@linux.alibaba.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent bbae8d1f

drivers/block/ublk_drv.c

+18 −4
Original line number Diff line number Diff line
@@ -50,7 +50,8 @@ 
#define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY \

		| UBLK_F_URING_CMD_COMP_IN_TASK \

		| UBLK_F_NEED_GET_DATA \

		| UBLK_F_USER_RECOVERY)

		| UBLK_F_USER_RECOVERY \

		| UBLK_F_USER_RECOVERY_REISSUE)



/* All UBLK_PARAM_TYPE_* should be included here */

#define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD)
@@ -325,6 +326,15 @@ static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id) 
			PAGE_SIZE);

}



static inline bool ublk_queue_can_use_recovery_reissue(

		struct ublk_queue *ubq)

{

	if ((ubq->flags & UBLK_F_USER_RECOVERY) &&

			(ubq->flags & UBLK_F_USER_RECOVERY_REISSUE))

		return true;

	return false;

}



static inline bool ublk_queue_can_use_recovery(

		struct ublk_queue *ubq)

{
@@ -629,12 +639,16 @@ static void ublk_complete_rq(struct request *req) 
 * Also aborting may not be started yet, keep in mind that one failed

 * request may be issued by block layer again.

 */

static void __ublk_fail_req(struct ublk_io *io, struct request *req)

static void __ublk_fail_req(struct ublk_queue *ubq, struct ublk_io *io,

		struct request *req)

{

	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

			blk_mq_end_request(req, BLK_STS_IOERR);

	}

}
@@ -962,7 +976,7 @@ static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq) 
			 */

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

			if (rq)

				__ublk_fail_req(io, rq);

				__ublk_fail_req(ubq, io, rq);

		}

	}

	ublk_put_device(ub);

include/uapi/linux/ublk_cmd.h

+2 −0
Original line number Diff line number Diff line
@@ -76,6 +76,8 @@ 


#define UBLK_F_USER_RECOVERY	(1UL << 3)



#define UBLK_F_USER_RECOVERY_REISSUE	(1UL << 4)



/* device state */

#define UBLK_S_DEV_DEAD	0

#define UBLK_S_DEV_LIVE	1