bridge: vlan: learn to count

Add support for per-VLAN Tx/Rx statistics. Every global vlan context gets
allocated a per-cpu stats which is then set in each per-port vlan context
for quick access. The br_allowed_ingress() common function is used to
account for Rx packets and the br_handle_vlan() common function is used
to account for Tx packets. Stats accounting is performed only if the
bridge-wide vlan_stats_enabled option is set either via sysfs or netlink.
A struct hole between vlan_enabled and vlan_proto is used for the new
option so it is in the same cache line. Currently it is binary (on/off)
but it is intentionally restricted to exactly 0 and 1 since other values
will be used in the future for different purposes (e.g. per-port stats).

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 2bfdb9c..95f7711 100644 (file)
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -272,6 +272,7 @@ enum {
        IFLA_BR_NF_CALL_ARPTABLES,
        IFLA_BR_VLAN_DEFAULT_PVID,
        IFLA_BR_PAD,
+       IFLA_BR_VLAN_STATS_ENABLED,
        __IFLA_BR_MAX,
 };
 

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 6bae112..7fba1f0 100644 (file)
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -850,6 +850,7 @@ static const struct nla_policy br_policy[IFLA_BR_MAX + 1] = {
        [IFLA_BR_NF_CALL_IP6TABLES] = { .type = NLA_U8 },
        [IFLA_BR_NF_CALL_ARPTABLES] = { .type = NLA_U8 },
        [IFLA_BR_VLAN_DEFAULT_PVID] = { .type = NLA_U16 },
+       [IFLA_BR_VLAN_STATS_ENABLED] = { .type = NLA_U8 },
 };
 
 static int br_changelink(struct net_device *brdev, struct nlattr *tb[],
@@ -921,6 +922,14 @@ static int br_changelink(struct net_device *brdev, struct nlattr *tb[],
                if (err)
                        return err;
        }
+
+       if (data[IFLA_BR_VLAN_STATS_ENABLED]) {
+               __u8 vlan_stats = nla_get_u8(data[IFLA_BR_VLAN_STATS_ENABLED]);
+
+               err = br_vlan_set_stats(br, vlan_stats);
+               if (err)
+                       return err;
+       }
 #endif
 
        if (data[IFLA_BR_GROUP_FWD_MASK]) {
@@ -1082,6 +1091,7 @@ static size_t br_get_size(const struct net_device *brdev)
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
               nla_total_size(sizeof(__be16)) + /* IFLA_BR_VLAN_PROTOCOL */
               nla_total_size(sizeof(u16)) +    /* IFLA_BR_VLAN_DEFAULT_PVID */
+              nla_total_size(sizeof(u8)) +     /* IFLA_BR_VLAN_STATS_ENABLED */
 #endif
               nla_total_size(sizeof(u16)) +    /* IFLA_BR_GROUP_FWD_MASK */
               nla_total_size(sizeof(struct ifla_bridge_id)) +   /* IFLA_BR_ROOT_ID */
@@ -1167,7 +1177,8 @@ static int br_fill_info(struct sk_buff *skb, const struct net_device *brdev)
 
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
        if (nla_put_be16(skb, IFLA_BR_VLAN_PROTOCOL, br->vlan_proto) ||
-           nla_put_u16(skb, IFLA_BR_VLAN_DEFAULT_PVID, br->default_pvid))
+           nla_put_u16(skb, IFLA_BR_VLAN_DEFAULT_PVID, br->default_pvid) ||
+           nla_put_u8(skb, IFLA_BR_VLAN_STATS_ENABLED, br->vlan_stats_enabled))
                return -EMSGSIZE;
 #endif
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index d9da857..12b6d82 100644 (file)
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -77,12 +77,21 @@ struct bridge_mcast_querier {
 };
 #endif
 
+struct br_vlan_stats {
+       u64 rx_bytes;
+       u64 rx_packets;
+       u64 tx_bytes;
+       u64 tx_packets;
+       struct u64_stats_sync syncp;
+};
+
 /**
  * struct net_bridge_vlan - per-vlan entry
  *
  * @vnode: rhashtable member
  * @vid: VLAN id
  * @flags: bridge vlan flags
+ * @stats: per-cpu VLAN statistics
  * @br: if MASTER flag set, this points to a bridge struct
  * @port: if MASTER flag unset, this points to a port struct
  * @refcnt: if MASTER flag set, this is bumped for each port referencing it
@@ -100,6 +109,7 @@ struct net_bridge_vlan {
        struct rhash_head               vnode;
        u16                             vid;
        u16                             flags;
+       struct br_vlan_stats __percpu   *stats;
        union {
                struct net_bridge       *br;
                struct net_bridge_port  *port;
@@ -342,6 +352,7 @@ struct net_bridge
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
        struct net_bridge_vlan_group    __rcu *vlgrp;
        u8                              vlan_enabled;
+       u8                              vlan_stats_enabled;
        __be16                          vlan_proto;
        u16                             default_pvid;
 #endif
@@ -691,6 +702,7 @@ int __br_vlan_filter_toggle(struct net_bridge *br, unsigned long val);
 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val);
 int __br_vlan_set_proto(struct net_bridge *br, __be16 proto);
 int br_vlan_set_proto(struct net_bridge *br, unsigned long val);
+int br_vlan_set_stats(struct net_bridge *br, unsigned long val);
 int br_vlan_init(struct net_bridge *br);
 int br_vlan_set_default_pvid(struct net_bridge *br, unsigned long val);
 int __br_vlan_set_default_pvid(struct net_bridge *br, u16 pvid);
@@ -880,7 +892,6 @@ static inline struct net_bridge_vlan_group *nbp_vlan_group_rcu(
 {
        return NULL;
 }
-
 #endif
 
 struct nf_br_ops {

diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index 70bddfd..beb4707 100644 (file)
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -731,6 +731,22 @@ static ssize_t default_pvid_store(struct device *d,
        return store_bridge_parm(d, buf, len, br_vlan_set_default_pvid);
 }
 static DEVICE_ATTR_RW(default_pvid);
+
+static ssize_t vlan_stats_enabled_show(struct device *d,
+                                      struct device_attribute *attr,
+                                      char *buf)
+{
+       struct net_bridge *br = to_bridge(d);
+       return sprintf(buf, "%u\n", br->vlan_stats_enabled);
+}
+
+static ssize_t vlan_stats_enabled_store(struct device *d,
+                                       struct device_attribute *attr,
+                                       const char *buf, size_t len)
+{
+       return store_bridge_parm(d, buf, len, br_vlan_set_stats);
+}
+static DEVICE_ATTR_RW(vlan_stats_enabled);
 #endif
 
 static struct attribute *bridge_attrs[] = {
@@ -778,6 +794,7 @@ static struct attribute *bridge_attrs[] = {
        &dev_attr_vlan_filtering.attr,
        &dev_attr_vlan_protocol.attr,
        &dev_attr_default_pvid.attr,
+       &dev_attr_vlan_stats_enabled.attr,
 #endif
        NULL
 };

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index e001152..065c353 100644 (file)
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -162,6 +162,17 @@ static struct net_bridge_vlan *br_vlan_get_master(struct net_bridge *br, u16 vid
        return masterv;
 }
 
+static void br_master_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));
+       free_percpu(v->stats);
+       v->stats = NULL;
+       kfree(v);
+}
+
 static void br_vlan_put_master(struct net_bridge_vlan *masterv)
 {
        struct net_bridge_vlan_group *vg;
@@ -174,7 +185,7 @@ static void br_vlan_put_master(struct net_bridge_vlan *masterv)
                rhashtable_remove_fast(&vg->vlan_hash,
                                       &masterv->vnode, br_vlan_rht_params);
                __vlan_del_list(masterv);
-               kfree_rcu(masterv, rcu);
+               call_rcu(&masterv->rcu, br_master_vlan_rcu_free);
        }
 }
 
@@ -230,6 +241,7 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags)
                if (!masterv)
                        goto out_filt;
                v->brvlan = masterv;
+               v->stats = masterv->stats;
        }
 
        /* Add the dev mac and count the vlan only if it's usable */
@@ -329,6 +341,7 @@ struct sk_buff *br_handle_vlan(struct net_bridge *br,
                               struct net_bridge_vlan_group *vg,
                               struct sk_buff *skb)
 {
+       struct br_vlan_stats *stats;
        struct net_bridge_vlan *v;
        u16 vid;
 
@@ -355,18 +368,27 @@ struct sk_buff *br_handle_vlan(struct net_bridge *br,
                        return NULL;
                }
        }
+       if (br->vlan_stats_enabled) {
+               stats = this_cpu_ptr(v->stats);
+               u64_stats_update_begin(&stats->syncp);
+               stats->tx_bytes += skb->len;
+               stats->tx_packets++;
+               u64_stats_update_end(&stats->syncp);
+       }
+
        if (v->flags & BRIDGE_VLAN_INFO_UNTAGGED)
                skb->vlan_tci = 0;
-
 out:
        return skb;
 }
 
 /* Called under RCU */
-static bool __allowed_ingress(struct net_bridge_vlan_group *vg, __be16 proto,
+static bool __allowed_ingress(const struct net_bridge *br,
+                             struct net_bridge_vlan_group *vg,
                              struct sk_buff *skb, u16 *vid)
 {
-       const struct net_bridge_vlan *v;
+       struct br_vlan_stats *stats;
+       struct net_bridge_vlan *v;
        bool tagged;
 
        BR_INPUT_SKB_CB(skb)->vlan_filtered = true;
@@ -375,7 +397,7 @@ static bool __allowed_ingress(struct net_bridge_vlan_group *vg, __be16 proto,
         * HW accelerated vlan tag.
         */
        if (unlikely(!skb_vlan_tag_present(skb) &&
-                    skb->protocol == proto)) {
+                    skb->protocol == br->vlan_proto)) {
                skb = skb_vlan_untag(skb);
                if (unlikely(!skb))
                        return false;
@@ -383,7 +405,7 @@ static bool __allowed_ingress(struct net_bridge_vlan_group *vg, __be16 proto,
 
        if (!br_vlan_get_tag(skb, vid)) {
                /* Tagged frame */
-               if (skb->vlan_proto != proto) {
+               if (skb->vlan_proto != br->vlan_proto) {
                        /* Protocol-mismatch, empty out vlan_tci for new tag */
                        skb_push(skb, ETH_HLEN);
                        skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
@@ -419,7 +441,7 @@ static bool __allowed_ingress(struct net_bridge_vlan_group *vg, __be16 proto,
                *vid = pvid;
                if (likely(!tagged))
                        /* Untagged Frame. */
-                       __vlan_hwaccel_put_tag(skb, proto, pvid);
+                       __vlan_hwaccel_put_tag(skb, br->vlan_proto, pvid);
                else
                        /* Priority-tagged Frame.
                         * At this point, We know that skb->vlan_tci had
@@ -428,13 +450,24 @@ static bool __allowed_ingress(struct net_bridge_vlan_group *vg, __be16 proto,
                         */
                        skb->vlan_tci |= pvid;
 
-               return true;
+               /* if stats are disabled we can avoid the lookup */
+               if (!br->vlan_stats_enabled)
+                       return true;
        }
-
-       /* Frame had a valid vlan tag.  See if vlan is allowed */
        v = br_vlan_find(vg, *vid);
-       if (v && br_vlan_should_use(v))
-               return true;
+       if (!v || !br_vlan_should_use(v))
+               goto drop;
+
+       if (br->vlan_stats_enabled) {
+               stats = this_cpu_ptr(v->stats);
+               u64_stats_update_begin(&stats->syncp);
+               stats->rx_bytes += skb->len;
+               stats->rx_packets++;
+               u64_stats_update_end(&stats->syncp);
+       }
+
+       return true;
+
 drop:
        kfree_skb(skb);
        return false;
@@ -452,7 +485,7 @@ bool br_allowed_ingress(const struct net_bridge *br,
                return true;
        }
 
-       return __allowed_ingress(vg, br->vlan_proto, skb, vid);
+       return __allowed_ingress(br, vg, skb, vid);
 }
 
 /* Called under RCU. */
@@ -542,6 +575,11 @@ int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
        if (!vlan)
                return -ENOMEM;
 
+       vlan->stats = netdev_alloc_pcpu_stats(struct br_vlan_stats);
+       if (!vlan->stats) {
+               kfree(vlan);
+               return -ENOMEM;
+       }
        vlan->vid = vid;
        vlan->flags = flags | BRIDGE_VLAN_INFO_MASTER;
        vlan->flags &= ~BRIDGE_VLAN_INFO_PVID;
@@ -549,8 +587,10 @@ int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
        if (flags & BRIDGE_VLAN_INFO_BRENTRY)
                atomic_set(&vlan->refcnt, 1);
        ret = __vlan_add(vlan, flags);
-       if (ret)
+       if (ret) {
+               free_percpu(vlan->stats);
                kfree(vlan);
+       }
 
        return ret;
 }
@@ -711,6 +751,20 @@ int br_vlan_set_proto(struct net_bridge *br, unsigned long val)
        return __br_vlan_set_proto(br, htons(val));
 }
 
+int br_vlan_set_stats(struct net_bridge *br, unsigned long val)
+{
+       switch (val) {
+       case 0:
+       case 1:
+               br->vlan_stats_enabled = 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;