Commit aec89dc5 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: keep q_usage_counter in atomic mode after del_gendisk 



Don't switch back to percpu mode to avoid the double RCU grace period
when tearing down SCSI devices.  After removing the disk only passthrough
commands can be send anyway.

Suggested-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Tested-by: default avatarDarrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20210929071241.934472-6-hch@lst.de


Tested-by: default avatarYi Zhang <yi.zhang@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 8e141f9e

block/blk-mq.c

+8 −1
Original line number Diff line number Diff line
@@ -188,9 +188,11 @@ void blk_mq_freeze_queue(struct request_queue *q) 
}

EXPORT_SYMBOL_GPL(blk_mq_freeze_queue);



void blk_mq_unfreeze_queue(struct request_queue *q)

void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic)

{

	mutex_lock(&q->mq_freeze_lock);

	if (force_atomic)

		q->q_usage_counter.data->force_atomic = true;

	q->mq_freeze_depth--;

	WARN_ON_ONCE(q->mq_freeze_depth < 0);

	if (!q->mq_freeze_depth) {
@@ -199,6 +201,11 @@ void blk_mq_unfreeze_queue(struct request_queue *q) 
	}

	mutex_unlock(&q->mq_freeze_lock);

}



void blk_mq_unfreeze_queue(struct request_queue *q)

{

	__blk_mq_unfreeze_queue(q, false);

}

EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);



/*

block/blk.h

+1 −0
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size, 
void blk_free_flush_queue(struct blk_flush_queue *q);



void blk_freeze_queue(struct request_queue *q);

void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);

void blk_queue_start_drain(struct request_queue *q);



#define BIO_INLINE_VECS 4

block/genhd.c

+2 −1
Original line number Diff line number Diff line
@@ -596,7 +596,8 @@ void del_gendisk(struct gendisk *disk) 
	/*

	 * Allow using passthrough request again after the queue is torn down.

	 */

	blk_mq_unfreeze_queue(q);

	blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q);

	__blk_mq_unfreeze_queue(q, true);



	if (!(disk->flags & GENHD_FL_HIDDEN)) {

		sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");