Re: [PATCH RFC 7/7] bridge: cfm: Bridge port remove.

[Nikolay Aleksandrov <nikolay@nvidia.com>]

On Fri, 2020-09-04 at 09:15 +0000, Henrik Bjoernlund wrote:
> This is addition of CFM functionality to delete MEP instances
> on a port that is removed from the bridge.
> A MEP can only exist on a port that is related to a bridge.
> 
> Signed-off-by: Henrik Bjoernlund  <henrik.bjoernlund@microchip.com>
> ---
>  net/bridge/br_cfm.c     | 13 +++++++++++++
>  net/bridge/br_if.c      |  1 +
>  net/bridge/br_private.h |  6 ++++++
>  3 files changed, 20 insertions(+)
> 
> diff --git a/net/bridge/br_cfm.c b/net/bridge/br_cfm.c
> index b7fed2c1d8ec..c724ce020ce3 100644
> --- a/net/bridge/br_cfm.c
> +++ b/net/bridge/br_cfm.c
> @@ -921,3 +921,16 @@ bool br_cfm_created(struct net_bridge *br)
>  {
>  	return !list_empty(&br->mep_list);
>  }
> +
> +/* Deletes the CFM instances on a specific bridge port
> + * note: called under rtnl_lock
> + */
> +void br_cfm_port_del(struct net_bridge *br, struct net_bridge_port *port)
> +{
> +	struct br_cfm_mep *mep;
> +
> +	list_for_each_entry_rcu(mep, &br->mep_list, head,
> +				lockdep_rtnl_is_held())

Use standard/non-rcu list traversing, rtnl is already held.

> +		if (mep->create.ifindex == port->dev->ifindex)
> +			mep_delete_implementation(br, mep);
> +}
> diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
> index a0e9a7937412..f7d2f472ae24 100644
> --- a/net/bridge/br_if.c
> +++ b/net/bridge/br_if.c
> @@ -334,6 +334,7 @@ static void del_nbp(struct net_bridge_port *p)
>  	spin_unlock_bh(&br->lock);
>  
>  	br_mrp_port_del(br, p);
> +	br_cfm_port_del(br, p);
>  
>  	br_ifinfo_notify(RTM_DELLINK, NULL, p);
>  
> diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
> index 53bcbdd21f34..5617255f0c0c 100644
> --- a/net/bridge/br_private.h
> +++ b/net/bridge/br_private.h
> @@ -1369,6 +1369,7 @@ int br_cfm_parse(struct net_bridge *br, struct net_bridge_port *p,
>  		 struct nlattr *attr, int cmd, struct netlink_ext_ack *extack);
>  int br_cfm_rx_frame_process(struct net_bridge_port *p, struct sk_buff *skb);
>  bool br_cfm_created(struct net_bridge *br);
> +void br_cfm_port_del(struct net_bridge *br, struct net_bridge_port *p);
>  int br_cfm_config_fill_info(struct sk_buff *skb, struct net_bridge *br);
>  int br_cfm_status_fill_info(struct sk_buff *skb,
>  			    struct net_bridge *br,
> @@ -1393,6 +1394,11 @@ static inline bool br_cfm_created(struct net_bridge *br)
>  	return false;
>  }
>  
> +static inline void br_cfm_port_del(struct net_bridge *br,
> +				   struct net_bridge_port *p)
> +{
> +}
> +
>  static inline int br_cfm_config_fill_info(struct sk_buff *skb, struct net_bridge *br)
>  {
>  	return -EOPNOTSUPP;