netdev - Re: [PATCHv2 net] ipvs: call ip_vs_dst_notifier earlier than ipv6_dev

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Message-ID: <20181116143711.wwskkrcpqhrybwpq@verge.net.au>
Date:   Fri, 16 Nov 2018 06:37:19 -0800
From:   Simon Horman <horms@...ge.net.au>
To:     Julian Anastasov <ja@....bg>,
        Pablo Neira Ayuso <pablo@...filter.org>
Cc:     Xin Long <lucien.xin@...il.com>,
        network dev <netdev@...r.kernel.org>,
        netfilter-devel@...r.kernel.org,
        "David S. Miller" <davem@...emloft.net>,
        Hans Schillstrom <hans@...illstrom.com>
Subject: Re: [PATCHv2 net] ipvs: call ip_vs_dst_notifier earlier than
 ipv6_dev_notf

On Fri, Nov 16, 2018 at 09:10:16AM +0200, Julian Anastasov wrote:
> 
> 	Hello,
> 
> On Thu, 15 Nov 2018, Xin Long wrote:
> 
> > ip_vs_dst_event is supposed to clean up all dst used in ipvs'
> > destinations when a net dev is going down. But it works only
> > when the dst's dev is the same as the dev from the event.
> > 
> > Now with the same priority but late registration,
> > ip_vs_dst_notifier is always called later than ipv6_dev_notf
> > where the dst's dev is set to lo for NETDEV_DOWN event.
> > 
> > As the dst's dev lo is not the same as the dev from the event
> > in ip_vs_dst_event, ip_vs_dst_notifier doesn't actually work.
> > Also as these dst have to wait for dest_trash_timer to clean
> > them up. It would cause some non-permanent kernel warnings:
> > 
> >   unregister_netdevice: waiting for br0 to become free. Usage count = 3
> > 
> > To fix it, call ip_vs_dst_notifier earlier than ipv6_dev_notf
> > by increasing its priority to ADDRCONF_NOTIFY_PRIORITY + 5.
> > 
> > Note that for ipv4 route fib_netdev_notifier doesn't set dst's
> > dev to lo in NETDEV_DOWN event, so this fix is only needed when
> > IP_VS_IPV6 is defined.
> > 
> > v1->v2:
> >   - apply it only when CONFIG_IP_VS_IPV6 is defined.
> > 
> > Fixes: 7a4f0761fce3 ("IPVS: init and cleanup restructuring")
> > Reported-by: Li Shuang <shuali@...hat.com>
> > Signed-off-by: Xin Long <lucien.xin@...il.com>
> 
> Acked-by: Julian Anastasov <ja@....bg>

Thanks,

Pablo, could you consider this for nf?

Acked-by: Simon Horman <horms@...ge.net.au>


> 
> > ---
> >  net/netfilter/ipvs/ip_vs_ctl.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
> > index 83395bf6..432141f 100644
> > --- a/net/netfilter/ipvs/ip_vs_ctl.c
> > +++ b/net/netfilter/ipvs/ip_vs_ctl.c
> > @@ -3980,6 +3980,9 @@ static void __net_exit ip_vs_control_net_cleanup_sysctl(struct netns_ipvs *ipvs)
> >  
> >  static struct notifier_block ip_vs_dst_notifier = {
> >  	.notifier_call = ip_vs_dst_event,
> > +#ifdef CONFIG_IP_VS_IPV6
> > +	.priority = ADDRCONF_NOTIFY_PRIORITY + 5,
> > +#endif
> >  };
> >  
> >  int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs)
> > -- 
> > 2.1.0
> 
> Regards
> 
> --
> Julian Anastasov <ja@....bg>
>