[Devel] [PATCH RH7] ms/net: allow macvlans to move to net namespace

[Andrew Vagin]

Acked-by: Andrew Vagin <avagin at virtuozzo.com>

On Mon, Oct 31, 2016 at 12:37:08PM +0300, Pavel Tikhomirov wrote:
> From: Francesco Ruggeri <fruggeri at arista.com>
> 
> We have a problem in macvlan criu test on VZ7:
> 
> https://ci.openvz.org/job/CRIU/job/CRIU-virtuozzo/branch/criu-dev/837/consoleFull
> ======================== Run zdtm/static/macvlan in ns =========================
> Start test
> Test is SUID
> ./macvlan --pidfile=macvlan.pid --outfile=macvlan.out
> RTNETLINK answers: Invalid argument
> Running zdtm/static/macvlan.hook(--post-start)
> 
> because macvlan_fix_features called from register_netdevice
> updates features from lowerdev and not dropping NETIF_F_NETNS_LOCAL.
> 
> And thus moving zdtmmvlan0 to other ns fails, so changing it to
> be mainstream like. (That do not changes behaviour in CT as macvlan
> is still forbidden there.)
> 
>   net: allow macvlans to move to net namespace
> 
>   I cannot move a macvlan interface created on top of a bonding interface
>   to a different namespace:
> 
>   % ip netns add dummy0
>   % ip link add link bond0 mac0 type macvlan
>   % ip link set mac0 netns dummy0
>   RTNETLINK answers: Invalid argument
>   %
> 
>   The problem seems to be that commit f9399814927a ("bonding: Don't allow
>   bond devices to change network namespaces.") sets NETIF_F_NETNS_LOCAL
>   on bonding interfaces, and commit 797f87f83b60 ("macvlan: fix netdev
>   feature propagation from lower device") causes macvlan interfaces
>   to inherit its features from the lower device.
> 
>   NETIF_F_NETNS_LOCAL should not be inherited from the lower device
>   by a macvlan.
>   Patch tested on 3.16.
> 
>   Signed-off-by: Francesco Ruggeri <fruggeri at arista.com>
>   Acked-by: Cong Wang <cwang at twopensource.com>
>   Signed-off-by: David S. Miller <davem at davemloft.net>
> 
> Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
> ---
>  drivers/net/macvlan.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> index 108ceb8..cb3d4de 100644
> --- a/drivers/net/macvlan.c
> +++ b/drivers/net/macvlan.c
> @@ -734,6 +734,7 @@ static netdev_features_t macvlan_fix_features(struct net_device *dev,
>  					     features,
>  					     mask);
>  	features |= ALWAYS_ON_FEATURES;
> +	features &= ~NETIF_F_NETNS_LOCAL;
>  
>  	return features;
>  }
> -- 
> 2.7.4
>