cdev_dev
if (kobject_get_unless_zero(&ub->cdev_dev.kobj))
put_device(&ub->cdev_dev);
struct device cdev_dev;
struct ublk_device *ub = container_of(dev, struct ublk_device, cdev_dev);
struct device *dev = &ub->cdev_dev;
cdev_device_del(&ub->cdev, &ub->cdev_dev);
ub->params.devt.char_major = MAJOR(ub->cdev_dev.devt);
ub->params.devt.char_minor = MINOR(ub->cdev_dev.devt);
if (stat.rdev != ub->cdev_dev.devt || !S_ISCHR(stat.mode))
fdev->parent = cdev_dev(idxd_cdev);
dev = cdev_dev(idxd_cdev);
cdev_device_del(&idxd_cdev->cdev, cdev_dev(idxd_cdev));
put_device(cdev_dev(idxd_cdev));