Re: [PATCH net-next] bridge: remove a redundant synchronize_net()

[Eric Dumazet <eric.dumazet@gmail.com>]

On Thu, 2013-04-04 at 08:44 -0700, Eric Dumazet wrote:

> Because maybe the synchronize_net() in netdev_rx_handler_unregister()
> is enough and you dont even need the call_rcu(). Thats was my question.

So we have the following sequence in team_port_del()

        netdev_rx_handler_unregister(port_dev);

        netdev_upper_dev_unlink(port_dev, dev);
        team_port_disable_netpoll(port);
        vlan_vids_del_by_dev(port_dev, dev);
        dev_uc_unsync(port_dev, dev);
        dev_mc_unsync(port_dev, dev);
        dev_close(port_dev);
        team_port_leave(team, port);

        __team_option_inst_mark_removed_port(team, port);
        __team_options_change_check(team);
        __team_option_inst_del_port(team, port);
        __team_port_change_port_removed(port);

        team_port_set_orig_dev_addr(port);
        dev_set_mtu(port_dev, port->orig.mtu);
        synchronize_rcu();
        kfree(port);

And I suspect we can remove synchronize_rcu() call.

But as this is a long list of operations, maybe some of them requires
the rcu grace period before kfree(port)