[PATCH net 0/2] vxlan: Fix vxlan counters.

[PATCH net 0/2] vxlan: Fix vxlan counters.

[Guillaume Nault]

Like most virtual devices, vxlan needs special care when updating its
netdevice counters. This is done in patch 1. Patch 2 just adds a
missing VNI counter update (found while working on patch 1).

Guillaume Nault (2):
  vxlan: Fix racy device stats updates.
  vxlan: Add missing VNI filter counter update in arp_reduce().

 drivers/net/vxlan/vxlan_core.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

-- 
2.39.2

[PATCH net 1/2] vxlan: Fix racy device stats updates.

[Guillaume Nault]

VXLAN devices update their stats locklessly. Therefore these counters
should either be stored in per-cpu data structures or the updates
should be done using atomic increments.

Since the net_device_core_stats infrastructure is already used in
vxlan_rcv(), use it for the other rx_dropped and tx_dropped counter
updates. Update the other counters atomically using DEV_STATS_INC().

Fixes: d342894c5d2f ("vxlan: virtual extensible lan")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
---
 drivers/net/vxlan/vxlan_core.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index ba319fc21957..0cd9e44c7be8 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1766,8 +1766,8 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 	skb_reset_network_header(skb);
 
 	if (!vxlan_ecn_decapsulate(vs, oiph, skb)) {
-		++vxlan->dev->stats.rx_frame_errors;
-		++vxlan->dev->stats.rx_errors;
+		DEV_STATS_INC(vxlan->dev, rx_frame_errors);
+		DEV_STATS_INC(vxlan->dev, rx_errors);
 		vxlan_vnifilter_count(vxlan, vni, vninode,
 				      VXLAN_VNI_STATS_RX_ERRORS, 0);
 		goto drop;
@@ -1837,7 +1837,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
 		goto out;
 
 	if (!pskb_may_pull(skb, arp_hdr_len(dev))) {
-		dev->stats.tx_dropped++;
+		dev_core_stats_tx_dropped_inc(dev);
 		goto out;
 	}
 	parp = arp_hdr(skb);
@@ -1893,7 +1893,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
 		reply->pkt_type = PACKET_HOST;
 
 		if (netif_rx(reply) == NET_RX_DROP) {
-			dev->stats.rx_dropped++;
+			dev_core_stats_rx_dropped_inc(dev);
 			vxlan_vnifilter_count(vxlan, vni, NULL,
 					      VXLAN_VNI_STATS_RX_DROPS, 0);
 		}
@@ -2052,7 +2052,7 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
 			goto out;
 
 		if (netif_rx(reply) == NET_RX_DROP) {
-			dev->stats.rx_dropped++;
+			dev_core_stats_rx_dropped_inc(dev);
 			vxlan_vnifilter_count(vxlan, vni, NULL,
 					      VXLAN_VNI_STATS_RX_DROPS, 0);
 		}
@@ -2263,7 +2263,7 @@ static void vxlan_encap_bypass(struct sk_buff *skb, struct vxlan_dev *src_vxlan,
 				      len);
 	} else {
 drop:
-		dev->stats.rx_dropped++;
+		dev_core_stats_rx_dropped_inc(dev);
 		vxlan_vnifilter_count(dst_vxlan, vni, NULL,
 				      VXLAN_VNI_STATS_RX_DROPS, 0);
 	}
@@ -2295,7 +2295,7 @@ static int encap_bypass_if_local(struct sk_buff *skb, struct net_device *dev,
 					   addr_family, dst_port,
 					   vxlan->cfg.flags);
 		if (!dst_vxlan) {
-			dev->stats.tx_errors++;
+			DEV_STATS_INC(dev, tx_errors);
 			vxlan_vnifilter_count(vxlan, vni, NULL,
 					      VXLAN_VNI_STATS_TX_ERRORS, 0);
 			kfree_skb(skb);
@@ -2559,7 +2559,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 	return;
 
 drop:
-	dev->stats.tx_dropped++;
+	dev_core_stats_tx_dropped_inc(dev);
 	vxlan_vnifilter_count(vxlan, vni, NULL, VXLAN_VNI_STATS_TX_DROPS, 0);
 	dev_kfree_skb(skb);
 	return;
@@ -2567,11 +2567,11 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 tx_error:
 	rcu_read_unlock();
 	if (err == -ELOOP)
-		dev->stats.collisions++;
+		DEV_STATS_INC(dev, collisions);
 	else if (err == -ENETUNREACH)
-		dev->stats.tx_carrier_errors++;
+		DEV_STATS_INC(dev, tx_carrier_errors);
 	dst_release(ndst);
-	dev->stats.tx_errors++;
+	DEV_STATS_INC(dev, tx_errors);
 	vxlan_vnifilter_count(vxlan, vni, NULL, VXLAN_VNI_STATS_TX_ERRORS, 0);
 	kfree_skb(skb);
 }
@@ -2604,7 +2604,7 @@ static void vxlan_xmit_nh(struct sk_buff *skb, struct net_device *dev,
 	return;
 
 drop:
-	dev->stats.tx_dropped++;
+	dev_core_stats_tx_dropped_inc(dev);
 	vxlan_vnifilter_count(netdev_priv(dev), vni, NULL,
 			      VXLAN_VNI_STATS_TX_DROPS, 0);
 	dev_kfree_skb(skb);
@@ -2642,7 +2642,7 @@ static netdev_tx_t vxlan_xmit_nhid(struct sk_buff *skb, struct net_device *dev,
 	return NETDEV_TX_OK;
 
 drop:
-	dev->stats.tx_dropped++;
+	dev_core_stats_tx_dropped_inc(dev);
 	vxlan_vnifilter_count(netdev_priv(dev), vni, NULL,
 			      VXLAN_VNI_STATS_TX_DROPS, 0);
 	dev_kfree_skb(skb);
@@ -2739,7 +2739,7 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 			    !is_multicast_ether_addr(eth->h_dest))
 				vxlan_fdb_miss(vxlan, eth->h_dest);
 
-			dev->stats.tx_dropped++;
+			dev_core_stats_tx_dropped_inc(dev);
 			vxlan_vnifilter_count(vxlan, vni, NULL,
 					      VXLAN_VNI_STATS_TX_DROPS, 0);
 			kfree_skb(skb);
-- 
2.39.2

Re: [PATCH net 1/2] vxlan: Fix racy device stats updates.

[Eric Dumazet]

On Fri, Apr 26, 2024 at 5:27 PM Guillaume Nault <gnault@redhat.com> wrote:
>
> VXLAN devices update their stats locklessly. Therefore these counters
> should either be stored in per-cpu data structures or the updates
> should be done using atomic increments.
>
> Since the net_device_core_stats infrastructure is already used in
> vxlan_rcv(), use it for the other rx_dropped and tx_dropped counter
> updates. Update the other counters atomically using DEV_STATS_INC().
>
> Fixes: d342894c5d2f ("vxlan: virtual extensible lan")
> Signed-off-by: Guillaume Nault <gnault@redhat.com>
> ---

Reviewed-by: Eric Dumazet <edumazet@google.com>

[PATCH net 2/2] vxlan: Add missing VNI filter counter update in arp_reduce().

[Guillaume Nault]

VXLAN stores per-VNI statistics using vxlan_vnifilter_count().
These statistics were not updated when arp_reduce() failed its
pskb_may_pull() call.

Use vxlan_vnifilter_count() to update the VNI counter when that
happens.

Fixes: 4095e0e1328a ("drivers: vxlan: vnifilter: per vni stats")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
---
 drivers/net/vxlan/vxlan_core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 0cd9e44c7be8..c9e4e03ad214 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1838,6 +1838,8 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
 
 	if (!pskb_may_pull(skb, arp_hdr_len(dev))) {
 		dev_core_stats_tx_dropped_inc(dev);
+		vxlan_vnifilter_count(vxlan, vni, NULL,
+				      VXLAN_VNI_STATS_TX_DROPS, 0);
 		goto out;
 	}
 	parp = arp_hdr(skb);
-- 
2.39.2

Re: [PATCH net 0/2] vxlan: Fix vxlan counters.

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Fri, 26 Apr 2024 17:27:15 +0200 you wrote:
> Like most virtual devices, vxlan needs special care when updating its
> netdevice counters. This is done in patch 1. Patch 2 just adds a
> missing VNI counter update (found while working on patch 1).
> 
> Guillaume Nault (2):
>   vxlan: Fix racy device stats updates.
>   vxlan: Add missing VNI filter counter update in arp_reduce().
> 
> [...]

Here is the summary with links:
  - [net,1/2] vxlan: Fix racy device stats updates.
    https://git.kernel.org/netdev/net/c/6dee402daba4
  - [net,2/2] vxlan: Add missing VNI filter counter update in arp_reduce().
    https://git.kernel.org/netdev/net/c/b22ea4ef4c34

You are awesome, thank you!
-- 
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