Sysfs files for a network device can not unconditionally take the
rtnl_lock as the bonding sysfs files do. If someone accesses those
sysfs files while the network device is being unregistered with the
rtnl_lock held we will deadlock.
So use trylock and restart_syscall to avoid this problem.
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>