unregister_netdevice: waiting for blkio.throttle. to become free. Usage count = 2
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4008 [inline]
 netdev_hold include/linux/netdevice.h:4037 [inline]
 dev_ifsioc+0x8cd/0x1160 net/core/dev_ioctl.c:387
 dev_ioctl+0x508/0xf70 net/core/dev_ioctl.c:588
 sock_do_ioctl+0x26b/0x450 net/socket.c:1218
 sock_ioctl+0x47f/0x770 net/socket.c:1321
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd