Commit f6661b1d authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

block: track queue dying state automatically for modeling queue freeze lockdep 



Now we only verify the outmost freeze & unfreeze in current context in case
that !q->mq_freeze_depth, so it is reliable to save queue lying state when
we want to lock the freeze queue since the state is one per-task variable
now.

Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241127135133.3952153-5-ming.lei@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent b9d4eee7

block/blk-mq.c

+3 −2
Original line number Diff line number Diff line
@@ -134,6 +134,7 @@ static bool blk_freeze_set_owner(struct request_queue *q, 
		q->mq_freeze_disk_dead = !q->disk ||

			test_bit(GD_DEAD, &q->disk->state) ||

			!blk_queue_registered(q);

		q->mq_freeze_queue_dying = blk_queue_dying(q);

		return true;

	}
@@ -190,7 +191,7 @@ bool __blk_freeze_queue_start(struct request_queue *q, 
void blk_freeze_queue_start(struct request_queue *q)

{

	if (__blk_freeze_queue_start(q, current))

		blk_freeze_acquire_lock(q, false);

		blk_freeze_acquire_lock(q);

}

EXPORT_SYMBOL_GPL(blk_freeze_queue_start);
@@ -238,7 +239,7 @@ bool __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic) 
void blk_mq_unfreeze_queue(struct request_queue *q)

{

	if (__blk_mq_unfreeze_queue(q, false))

		blk_unfreeze_release_lock(q, false);

		blk_unfreeze_release_lock(q);

}

EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);

block/blk.h

+6 −6
Original line number Diff line number Diff line
@@ -721,26 +721,26 @@ void blk_integrity_prepare(struct request *rq); 
void blk_integrity_complete(struct request *rq, unsigned int nr_bytes);



#ifdef CONFIG_LOCKDEP

static inline void blk_freeze_acquire_lock(struct request_queue *q, bool queue_dying)

static inline void blk_freeze_acquire_lock(struct request_queue *q)

{

	if (!q->mq_freeze_disk_dead)

		rwsem_acquire(&q->io_lockdep_map, 0, 1, _RET_IP_);

	if (!queue_dying)

	if (!q->mq_freeze_queue_dying)

		rwsem_acquire(&q->q_lockdep_map, 0, 1, _RET_IP_);

}



static inline void blk_unfreeze_release_lock(struct request_queue *q, bool queue_dying)

static inline void blk_unfreeze_release_lock(struct request_queue *q)

{

	if (!queue_dying)

	if (!q->mq_freeze_queue_dying)

		rwsem_release(&q->q_lockdep_map, _RET_IP_);

	if (!q->mq_freeze_disk_dead)

		rwsem_release(&q->io_lockdep_map, _RET_IP_);

}

#else

static inline void blk_freeze_acquire_lock(struct request_queue *q, bool queue_dying)

static inline void blk_freeze_acquire_lock(struct request_queue *q)

{

}

static inline void blk_unfreeze_release_lock(struct request_queue *q, bool queue_dying)

static inline void blk_unfreeze_release_lock(struct request_queue *q)

{

}

#endif

block/genhd.c

+3 −4
Original line number Diff line number Diff line
@@ -661,7 +661,7 @@ void del_gendisk(struct gendisk *disk) 
	struct request_queue *q = disk->queue;

	struct block_device *part;

	unsigned long idx;

	bool start_drain, queue_dying;

	bool start_drain;



	might_sleep();
@@ -690,9 +690,8 @@ void del_gendisk(struct gendisk *disk) 
	 */

	mutex_lock(&disk->open_mutex);

	start_drain = __blk_mark_disk_dead(disk);

	queue_dying = blk_queue_dying(q);

	if (start_drain)

		blk_freeze_acquire_lock(q, queue_dying);

		blk_freeze_acquire_lock(q);

	xa_for_each_start(&disk->part_tbl, idx, part, 1)

		drop_partition(part);

	mutex_unlock(&disk->open_mutex);
@@ -748,7 +747,7 @@ void del_gendisk(struct gendisk *disk) 
		blk_mq_exit_queue(q);



	if (start_drain)

		blk_unfreeze_release_lock(q, queue_dying);

		blk_unfreeze_release_lock(q);

}

EXPORT_SYMBOL(del_gendisk);

include/linux/blkdev.h

+5 −1
Original line number Diff line number Diff line
@@ -581,8 +581,12 @@ struct request_queue { 
#ifdef CONFIG_LOCKDEP

	struct task_struct	*mq_freeze_owner;

	int			mq_freeze_owner_depth;

	/* Records disk state in current context, used in unfreeze queue */

	/*

	 * Records disk & queue state in current context, used in unfreeze

	 * queue

	 */

	bool			mq_freeze_disk_dead;

	bool			mq_freeze_queue_dying;

#endif

	wait_queue_head_t	mq_freeze_wq;

	/*