Commit d563792c authored by Yu Kuai's avatar Yu Kuai Committed by Jens Axboe
Browse files

dm: make sure create and remove dm device won't race with open and close table 



open_table_device() and close_table_device() is protected by
table_devices_lock, hence use it to protect add_disk() and
del_gendisk().

Prepare to track per-add_disk holder relations in dm.

Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Reviewed-by: default avatarMike Snitzer <snitzer@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221115141054.1051801-6-yukuai1@huaweicloud.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 7b586583

drivers/md/dm.c

+16 −0
Original line number Diff line number Diff line
@@ -1952,7 +1952,14 @@ static void cleanup_mapped_device(struct mapped_device *md) 
		spin_unlock(&_minor_lock);

		if (dm_get_md_type(md) != DM_TYPE_NONE) {

			dm_sysfs_exit(md);



			/*

			 * Hold lock to make sure del_gendisk() won't concurrent

			 * with open/close_table_device().

			 */

			mutex_lock(&md->table_devices_lock);

			del_gendisk(md->disk);

			mutex_unlock(&md->table_devices_lock);

		}

		dm_queue_destroy_crypto_profile(md->queue);

		put_disk(md->disk);
@@ -2312,15 +2319,24 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t) 
	if (r)

		return r;



	/*

	 * Hold lock to make sure add_disk() and del_gendisk() won't concurrent

	 * with open_table_device() and close_table_device().

	 */

	mutex_lock(&md->table_devices_lock);

	r = add_disk(md->disk);

	mutex_unlock(&md->table_devices_lock);

	if (r)

		return r;



	r = dm_sysfs_init(md);

	if (r) {

		mutex_lock(&md->table_devices_lock);

		del_gendisk(md->disk);

		mutex_unlock(&md->table_devices_lock);

		return r;

	}



	md->type = type;

	return 0;

}