Re: [PATCH v5 net-next 07/15] net: bridge: mst: Add helper to map an MSTI to a VID set

Vladimir Oltean
2022-03-17T00:43:33Z

On Wed, Mar 16, 2022 at 04:08:49PM +0100, Tobias Waldekranz wrote:
> br_mst_get_info answers the question: "On this bridge, which VIDs are
> mapped to the given MSTI?"
>
> This is useful in switchdev drivers, which might have to fan-out
> operations, relating to an MSTI, per VLAN.
>
> An example: When a port's MST state changes from forwarding to
> blocking, a driver may choose to flush the dynamic FDB entries on that
> port to get faster reconvergence of the network, but this should only
> be done in the VLANs that are managed by the MSTI in question.
>
> Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
> ---

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>

> include/linux/if_bridge.h | 7 +++++++
> net/bridge/br_mst.c | 26 ++++++++++++++++++++++++++
> 2 files changed, 33 insertions(+)
>
> diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
> index 3aae023a9353..1cf0cc46d90d 100644
> --- a/include/linux/if_bridge.h
> +++ b/include/linux/if_bridge.h
> @@ -119,6 +119,7 @@ int br_vlan_get_info(const struct net_device *dev, u16 vid,
> struct bridge_vlan_info *p_vinfo);
> int br_vlan_get_info_rcu(const struct net_device *dev, u16 vid,
> struct bridge_vlan_info *p_vinfo);
> +int br_mst_get_info(const struct net_device *dev, u16 msti, unsigned long *vids);
> #else
> static inline bool br_vlan_enabled(const struct net_device *dev)
> {
> @@ -151,6 +152,12 @@ static inline int br_vlan_get_info_rcu(const struct net_device *dev, u16 vid,
> {
> return -EINVAL;
> }
> +
> +static inline int br_mst_get_info(const struct net_device *dev, u16 msti,
> + unsigned long *vids)
> +{
> + return -EINVAL;
> +}
> #endif
>
> #if IS_ENABLED(CONFIG_BRIDGE)
> diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
> index 00935a19afcc..00b36e629224 100644
> --- a/net/bridge/br_mst.c
> +++ b/net/bridge/br_mst.c
> @@ -13,6 +13,32 @@
>
> DEFINE_STATIC_KEY_FALSE(br_mst_used);
>
> +int br_mst_get_info(const struct net_device *dev, u16 msti, unsigned long *vids)
> +{
> + const struct net_bridge_vlan_group *vg;
> + const struct net_bridge_vlan *v;
> + const struct net_bridge *br;
> +
> + ASSERT_RTNL();
> +
> + if (!netif_is_bridge_master(dev))
> + return -EINVAL;
> +
> + br = netdev_priv(dev);
> + if (!br_opt_get(br, BROPT_MST_ENABLED))
> + return -EINVAL;
> +
> + vg = br_vlan_group(br);
> +
> + list_for_each_entry(v, &vg->vlan_list, vlist) {
> + if (v->msti == msti)
> + __set_bit(v->vid, vids);
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(br_mst_get_info);
> +
> static void br_mst_vlan_set_state(struct net_bridge_port *p, struct net_bridge_vlan *v,
> u8 state)
> {
> --
> 2.25.1
>