Commit 89f871af authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

dm: delay registering the gendisk 



device mapper is currently the only outlier that tries to call
register_disk after add_disk, leading to fairly inconsistent state
of these block layer data structures.  Instead change device-mapper
to just register the gendisk later now that the holder mechanism
can cope with that.

Note that this introduces a user visible change: the dm kobject is
now only visible after the initial table has been loaded.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20210804094147.459763-8-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ba305859

drivers/md/dm-rq.c

+0 −1
Original line number Diff line number Diff line
@@ -559,7 +559,6 @@ int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t) 
	err = blk_mq_init_allocated_queue(md->tag_set, md->queue);

	if (err)

		goto out_tag_set;

	elevator_init_mq(md->queue);

	return 0;



out_tag_set:

drivers/md/dm.c

+11 −12
Original line number Diff line number Diff line
@@ -1693,7 +1693,10 @@ static void cleanup_mapped_device(struct mapped_device *md) 
		spin_lock(&_minor_lock);

		md->disk->private_data = NULL;

		spin_unlock(&_minor_lock);

		if (dm_get_md_type(md) != DM_TYPE_NONE) {

			dm_sysfs_exit(md);

			del_gendisk(md->disk);

		}

		dm_queue_destroy_keyslot_manager(md->queue);

		blk_cleanup_disk(md->disk);

	}
@@ -1788,7 +1791,6 @@ static struct mapped_device *alloc_dev(int minor) 
			goto bad;

	}



	add_disk_no_queue_reg(md->disk);

	format_dev_t(md->name, MKDEV(_major, minor));



	md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
@@ -1989,19 +1991,12 @@ static struct dm_table *__unbind(struct mapped_device *md) 
 */

int dm_create(int minor, struct mapped_device **result)

{

	int r;

	struct mapped_device *md;



	md = alloc_dev(minor);

	if (!md)

		return -ENXIO;



	r = dm_sysfs_init(md);

	if (r) {

		free_dev(md);

		return r;

	}



	*result = md;

	return 0;

}
@@ -2081,10 +2076,15 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t) 
	r = dm_table_set_restrictions(t, md->queue, &limits);

	if (r)

		return r;

	md->type = type;



	blk_register_queue(md->disk);

	add_disk(md->disk);



	r = dm_sysfs_init(md);

	if (r) {

		del_gendisk(md->disk);

		return r;

	}

	md->type = type;

	return 0;

}
@@ -2190,7 +2190,6 @@ static void __dm_destroy(struct mapped_device *md, bool wait) 
		DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",

		       dm_device_name(md), atomic_read(&md->holders));



	dm_sysfs_exit(md);

	dm_table_destroy(__unbind(md));

	free_dev(md);

}