fib_nh_dev_tracker
netdev_hold(nh->fib_nh_dev, &nh->fib_nh_dev_tracker,
netdev_hold(dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC);
netdev_hold(dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC);
netdev_hold(nh->fib_nh_dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC);
netdev_tracker_alloc(nh->fib_nh_dev, &nh->fib_nh_dev_tracker,
netdevice_tracker *dev_tracker = &fib6_nh->fib_nh_dev_tracker;