dm: convert to idr_alloc()

 */

static int specific_minor(int minor)

{

	int r, m;

	int r;

	if (minor >= (1 << MINORBITS))

		return -EINVAL;

	r = idr_pre_get(&_minor_idr, GFP_KERNEL);

	if (!r)

		return -ENOMEM;

	idr_preload(GFP_KERNEL);

	spin_lock(&_minor_lock);

	if (idr_find(&_minor_idr, minor)) {

		r = -EBUSY;

		goto out;

	}

	r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m);

	if (r)

		goto out;

	if (m != minor) {

		idr_remove(&_minor_idr, m);

		r = -EBUSY;

		goto out;

	}

	r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);

out:

	spin_unlock(&_minor_lock);

	return r;

	idr_preload_end();

	if (r < 0)

		return r == -ENOSPC ? -EBUSY : r;

	return 0;

}

static int next_free_minor(int *minor)

{

	int r, m;

	r = idr_pre_get(&_minor_idr, GFP_KERNEL);

	if (!r)

		return -ENOMEM;

	int r;

	idr_preload(GFP_KERNEL);

	spin_lock(&_minor_lock);

	r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m);

	if (r)

		goto out;

	r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);

	if (m >= (1 << MINORBITS)) {

		idr_remove(&_minor_idr, m);

		r = -ENOSPC;

		goto out;

	}

	*minor = m;

out:

	spin_unlock(&_minor_lock);

	idr_preload_end();

	if (r < 0)

		return r;

	*minor = r;

	return 0;

}

static const struct block_device_operations dm_blk_dops;