Often the code for example in drivers is interested in getting notifier
call only from certain network namespace. In addition to the existing
global netdevice notifier chain introduce per-netns chains and allow
users to register to that. Eventually this would eliminate unnecessary
overhead in case there are many netdevices in many network namespaces.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>