net: bridge: add support for per-port vlan stats

This patch adds an option to have per-port vlan stats instead of the
default global stats. The option can be set only when there are no port
vlans in the bridge since we need to allocate the stats if it is set
when vlans are being added to ports (and respectively free them
when being deleted). Also bump RTNL_MAX_TYPE as the bridge is the
largest user of options. The current stats design allows us to add
these without any changes to the fast-path, it all comes down to
the per-vlan stats pointer which, if this option is enabled, will
be allocated for each port vlan instead of using the global bridge-wide
one.

CC: bridge@lists.linux-foundation.org
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 47 insertions, 2 deletions

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 5942e03dd845..9b707234e4ae 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -190,6 +190,19 @@ static void br_vlan_put_master(struct net_bridge_vlan *masterv)
 	}
 }
 
+static void nbp_vlan_rcu_free(struct rcu_head *rcu)
+{
+	struct net_bridge_vlan *v;
+
+	v = container_of(rcu, struct net_bridge_vlan, rcu);
+	WARN_ON(br_vlan_is_master(v));
+	/* if we had per-port stats configured then free them here */
+	if (v->brvlan->stats != v->stats)
+		free_percpu(v->stats);
+	v->stats = NULL;
+	kfree(v);
+}
+
 /* This is the shared VLAN add function which works for both ports and bridge
  * devices. There are four possible calls to this function in terms of the
  * vlan entry type:
@@ -245,7 +258,15 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags)
 		if (!masterv)
 			goto out_filt;
 		v->brvlan = masterv;
-		v->stats = masterv->stats;
+		if (br_opt_get(br, BROPT_VLAN_STATS_PER_PORT)) {
+			v->stats = netdev_alloc_pcpu_stats(struct br_vlan_stats);
+			if (!v->stats) {
+				err = -ENOMEM;
+				goto out_filt;
+			}
+		} else {
+			v->stats = masterv->stats;
+		}
 	} else {
 		err = br_switchdev_port_vlan_add(dev, v->vid, flags);
 		if (err && err != -EOPNOTSUPP)
@@ -329,7 +350,7 @@ static int __vlan_del(struct net_bridge_vlan *v)
 		rhashtable_remove_fast(&vg->vlan_hash, &v->vnode,
 				       br_vlan_rht_params);
 		__vlan_del_list(v);
-		kfree_rcu(v, rcu);
+		call_rcu(&v->rcu, nbp_vlan_rcu_free);
 	}
 
 	br_vlan_put_master(masterv);
@@ -830,6 +851,30 @@ int br_vlan_set_stats(struct net_bridge *br, unsigned long val)
 	return 0;
 }
 
+int br_vlan_set_stats_per_port(struct net_bridge *br, unsigned long val)
+{
+	struct net_bridge_port *p;
+
+	/* allow to change the option if there are no port vlans configured */
+	list_for_each_entry(p, &br->port_list, list) {
+		struct net_bridge_vlan_group *vg = nbp_vlan_group(p);
+
+		if (vg->num_vlans)
+			return -EBUSY;
+	}
+
+	switch (val) {
+	case 0:
+	case 1:
+		br_opt_toggle(br, BROPT_VLAN_STATS_PER_PORT, !!val);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static bool vlan_default_pvid(struct net_bridge_vlan_group *vg, u16 vid)
 {
 	struct net_bridge_vlan *v;