Re: [PATCH v3 net-next 10/12] net: dsa: replay VLANs installed on port when joining the bridge

[Nikolay Aleksandrov]

On 21/03/2021 00:34, Vladimir Oltean wrote:
> From: Vladimir Oltean <vladimir.oltean@xxxxxxx>
> 
> Currently this simple setup:
> 
> ip link add br0 type bridge vlan_filtering 1
> ip link add bond0 type bond
> ip link set bond0 master br0
> ip link set swp0 master bond0
> 
> will not work because the bridge has created the PVID in br_add_if ->
> nbp_vlan_init, and it has notified switchdev of the existence of VLAN 1,
> but that was too early, since swp0 was not yet a lower of bond0, so it
> had no reason to act upon that notification.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
> ---
> Changes in v3:
> Made the br_vlan_replay shim return -EOPNOTSUPP.
> 
>  include/linux/if_bridge.h | 10 ++++++
>  net/bridge/br_vlan.c      | 71 +++++++++++++++++++++++++++++++++++++++
>  net/dsa/port.c            |  6 ++++
>  3 files changed, 87 insertions(+)
[snip]
> +int br_vlan_replay(struct net_device *br_dev, struct net_device *dev,
> +		   struct notifier_block *nb, struct netlink_ext_ack *extack)
> +{
> +	struct net_bridge_vlan_group *vg;
> +	struct net_bridge_vlan *v;
> +	struct net_bridge_port *p;
> +	struct net_bridge *br;
> +	int err = 0;
> +	u16 pvid;
> +
> +	ASSERT_RTNL();
> +
> +	if (!netif_is_bridge_master(br_dev))
> +		return -EINVAL;
> +
> +	if (!netif_is_bridge_master(dev) && !netif_is_bridge_port(dev))
> +		return -EINVAL;
> +
> +	if (netif_is_bridge_master(dev)) {
> +		br = netdev_priv(dev);
> +		vg = br_vlan_group(br);
> +		p = NULL;
> +	} else {
> +		p = br_port_get_rtnl(dev);
> +		if (WARN_ON(!p))
> +			return -EINVAL;
> +		vg = nbp_vlan_group(p);
> +		br = p->br;
> +	}
> +
> +	if (!vg)
> +		return 0;
> +
> +	pvid = br_get_pvid(vg);
> +
> +	list_for_each_entry(v, &vg->vlan_list, vlist) {
> +		struct switchdev_obj_port_vlan vlan = {
> +			.obj.orig_dev = dev,
> +			.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
> +			.flags = br_vlan_flags(v, pvid),
> +			.vid = v->vid,
> +		};
> +
> +		if (!br_vlan_should_use(v))
> +			continue;
> +
> +		br_vlan_replay_one(nb, dev, &vlan, extack);
> +		if (err)
> +			return err;
> +	}
> +
> +	return err;
> +}

EXPORT_SYMBOL_GPL ?

>  /* check if v_curr can enter a range ending in range_end */
>  bool br_vlan_can_enter_range(const struct net_bridge_vlan *v_curr,
>  			     const struct net_bridge_vlan *range_end)
> diff --git a/net/dsa/port.c b/net/dsa/port.c
> index d21a511f1e16..84775e253ee8 100644
> --- a/net/dsa/port.c
> +++ b/net/dsa/port.c
> @@ -209,6 +209,12 @@ static int dsa_port_switchdev_sync(struct dsa_port *dp,
>  	if (err && err != -EOPNOTSUPP)
>  		return err;
>  
> +	err = br_vlan_replay(br, brport_dev,
> +			     &dsa_slave_switchdev_blocking_notifier,
> +			     extack);
> +	if (err && err != -EOPNOTSUPP)
> +		return err;
> +
>  	return 0;
>  }
>  
>