On 5/3/17 11:07 PM, Cong Wang wrote:
> For each netns (except init_net), we initialize its null entry
> in 3 places:
>
> 1) The template itself, as we use kmemdup()
> 2) Code around dst_init_metrics() in ip6_route_net_init()
> 3) ip6_route_dev_notify(), which is supposed to initialize it after
> loopback registers
>
> Unfortunately the last one still happens in a wrong order because
> we expect to initialize net->ipv6.ip6_null_entry->rt6i_idev to
> net->loopback_dev's idev, so we have to do that after we add
> idev to it. However, this notifier has priority == 0 same as
> ipv6_dev_notf, and ipv6_dev_notf is registered after
> ip6_route_dev_notifier so it is called actually after
> ip6_route_dev_notifier.
>
> Fix it by specifying a smaller priority for ip6_route_dev_notifier.
>
> Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
> ---
> net/ipv6/route.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index 2f11366..4dbf7e2 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -4024,7 +4024,7 @@ static struct pernet_operations ip6_route_net_late_ops
> = {
>
> static struct notifier_block ip6_route_dev_notifier = {
> .notifier_call = ip6_route_dev_notify,
> - .priority = 0,
> + .priority = -10, /* Must be called after addrconf_notify!! */
> };
>
> void __init ip6_route_init_special_entries(void)
>
And I see a refcnt problem with this change:
root@kenny-jessie2:~# unshare -n
root@kenny-jessie2:~# logout
root@kenny-jessie2:~# unshare -n
Message from syslogd@kenny-jessie2 at May 4 07:04:38 ...
kernel:[ 62.581552] unregister_netdevice: waiting for lo to become
free. Usage count = 1
