static void __dm_destroy(struct mapped_device *md, bool wait)
{
	struct request_queue *q = dm_get_md_queue(md);
	struct dm_table *map;
	int srcu_idx;

	might_sleep();

	spin_lock(&_minor_lock);
	idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
	set_bit(DMF_FREEING, &md->flags);
	spin_unlock(&_minor_lock);

	blk_set_queue_dying(q);

	if (dm_request_based(md) && md->kworker_task)
		kthread_flush_worker(&md->kworker);

	/*
	 * Take suspend_lock so that presuspend and postsuspend methods
	 * do not race with internal suspend.
	 */
	mutex_lock(&md->suspend_lock);
	map = dm_get_live_table(md, &srcu_idx);
	if (!dm_suspended_md(md)) {
		dm_table_presuspend_targets(map);
		dm_table_postsuspend_targets(map);
	}
	/* dm_put_live_table must be before msleep, otherwise deadlock is possible */
	dm_put_live_table(md, srcu_idx);
	mutex_unlock(&md->suspend_lock);

	/*
	 * Rare, but there may be I/O requests still going to complete,
	 * for example.  Wait for all references to disappear.
	 * No one should increment the reference count of the mapped_device,
	 * after the mapped_device state becomes DMF_FREEING.
	 */
	if (wait)
		while (atomic_read(&md->holders))
			msleep(1);
	else if (atomic_read(&md->holders))
		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);
}
static void __dm_destroy(struct mapped_device *md, bool wait)
{
	struct request_queue *q = dm_get_md_queue(md);
	struct dm_table *map;
	int srcu_idx;

	might_sleep();

	spin_lock(&_minor_lock);
	idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
	set_bit(DMF_FREEING, &md->flags);
	spin_unlock(&_minor_lock);

	blk_set_queue_dying(q);

	if (dm_request_based(md) && md->kworker_task)
		kthread_flush_worker(&md->kworker);

	 
	mutex_lock(&md->suspend_lock);
	map = dm_get_live_table(md, &srcu_idx);
	if (!dm_suspended_md(md)) {
		dm_table_presuspend_targets(map);
		dm_table_postsuspend_targets(map);
	}
	 
	dm_put_live_table(md, srcu_idx);
	mutex_unlock(&md->suspend_lock);

	 
	if (wait)
		while (atomic_read(&md->holders))
			msleep(1);
	else if (atomic_read(&md->holders))
		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);
}