Merge branch 'bridge-per-vlan-stats'

Nikolay Aleksandrov says:

====================
bridge: per-vlan stats

This set adds support for bridge per-vlan statistics.
In order to be able to dump statistics for many vlans we need a way to
continue dumping after reaching maximum size, thus patches 01 and 02 extend
the new stats API with a per-device extended link stats attribute and
callback which can save its local state and continue where it left off
afterwards. I considered using the already existing "fill_xstats" callback
but it gets confusing since we need to separate the linkinfo dump from the
new stats api dump and adding a flag/argument to do that just looks messy.
I don't think the rtnl_link_ops size is an issue, so adding these seemed
like the cleaner approach.

Patches 03 and 04 add the stats support and netlink dump support
respectively. The stats accounting is controlled via a bridge option which
is default off, thus the performance impact is kept minimal.
I've tested this set with both old and modified iproute2, kmemleak on and
some traffic stress tests while adding/removing vlans and ports.

v3:
 - drop the RCU pvid patch and remove one pointer fetch as requested
 - make stats accounting optional with default to off, the option is in the
   same cache line as vlan_proto and vlan_enabled, so it is already fetched
   before the fast path check thus the performance impact is minimal, this
   also allows us to avoid one vlan lookup and return early when using pvid
 - rebased and retested

v2:
 - Improve the error checking, rename lidx to prividx and save the current
   idx user instead of restricting it to one in patch 01
 - squash patch 02 into 01 and remove the restriction
 - add callback descriptions, improve the size calculation and change the
   xstats message structure to have an embedding level per rtnl link type
   so we can avoid one call to get the link type (and thus filter on it)
   and also each link type can now have any number of private attributes
   inside
 - fix a problem where the vlan stats are not dumped if the bridge has 0
   vlans on it but has vlans on the ports, add bridge link type private
   attributes and also add paddings for future extensions to avoid at least
   a few netlink attributes and improve struct alignment
 - drop the is_skb_forwardable argument constifying patch as it's not
   needed anymore, but it's a nice cleanup which I'll send separately
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 95 insertions, 14 deletions

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index e001152d6ad1..b6de4f457161 100644
--- 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;
@@ -1000,3 +1054,30 @@ void nbp_vlan_flush(struct net_bridge_port *port)
 	synchronize_rcu();
 	__vlan_group_free(vg);
 }
+
+void br_vlan_get_stats(const struct net_bridge_vlan *v,
+		       struct br_vlan_stats *stats)
+{
+	int i;
+
+	memset(stats, 0, sizeof(*stats));
+	for_each_possible_cpu(i) {
+		u64 rxpackets, rxbytes, txpackets, txbytes;
+		struct br_vlan_stats *cpu_stats;
+		unsigned int start;
+
+		cpu_stats = per_cpu_ptr(v->stats, i);
+		do {
+			start = u64_stats_fetch_begin_irq(&cpu_stats->syncp);
+			rxpackets = cpu_stats->rx_packets;
+			rxbytes = cpu_stats->rx_bytes;
+			txbytes = cpu_stats->tx_bytes;
+			txpackets = cpu_stats->tx_packets;
+		} while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start));
+
+		stats->rx_packets += rxpackets;
+		stats->rx_bytes += rxbytes;
+		stats->tx_bytes += txbytes;
+		stats->tx_packets += txpackets;
+	}
+}