unregister_netdevice: waiting for blkio.throttle. to become free. Usage count = 2
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4051 [inline]
 netdev_hold include/linux/netdevice.h:4080 [inline]
 dev_ifsioc+0x7ed/0xea0 net/core/dev_ioctl.c:387
 dev_ioctl+0x578/0xea0 net/core/dev_ioctl.c:588
 sock_do_ioctl+0x222/0x2f0 net/socket.c:1218
 sock_ioctl+0x4ed/0x6e0 net/socket.c:1321
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2