ipv6: tunnels: use DEV_STATS_INC()

Most of code paths in tunnels are lockless (eg NETIF_F_LLTX in tx).

Adopt SMP safe DEV_STATS_{INC|ADD}() to update dev->stats fields.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ip6_gre.c

@@ -895,7 +895,6 @@ static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 	struct net_device *dev)
 {
 	struct ip6_tnl *t = netdev_priv(dev);
-	struct net_device_stats *stats = &t->dev->stats;
 	__be16 payload_protocol;
 	int ret;
 
@@ -925,8 +924,8 @@ static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
 
 tx_err:
 	if (!t->parms.collect_md || !IS_ERR(skb_tunnel_info_txcheck(skb)))
-		stats->tx_errors++;
-	stats->tx_dropped++;
+		DEV_STATS_INC(dev, tx_errors);
+	DEV_STATS_INC(dev, tx_dropped);
 	kfree_skb(skb);
 	return NETDEV_TX_OK;
 }
@@ -937,7 +936,6 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
 	struct ip_tunnel_info *tun_info = NULL;
 	struct ip6_tnl *t = netdev_priv(dev);
 	struct dst_entry *dst = skb_dst(skb);
-	struct net_device_stats *stats;
 	bool truncate = false;
 	int encap_limit = -1;
 	__u8 dsfield = false;
@@ -1086,10 +1084,9 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
 	return NETDEV_TX_OK;
 
 tx_err:
-	stats = &t->dev->stats;
 	if (!IS_ERR(tun_info))
-		stats->tx_errors++;
-	stats->tx_dropped++;
+		DEV_STATS_INC(dev, tx_errors);
+	DEV_STATS_INC(dev, tx_dropped);
 	kfree_skb(skb);
 	return NETDEV_TX_OK;
 }

net/ipv6/ip6_tunnel.c

@@ -803,8 +803,8 @@ static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 	     (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
 	    ((tpi->flags & TUNNEL_CSUM) &&
 	     !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
-		tunnel->dev->stats.rx_crc_errors++;
-		tunnel->dev->stats.rx_errors++;
+		DEV_STATS_INC(tunnel->dev, rx_crc_errors);
+		DEV_STATS_INC(tunnel->dev, rx_errors);
 		goto drop;
 	}
 
@@ -812,8 +812,8 @@ static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 		if (!(tpi->flags & TUNNEL_SEQ) ||
 		    (tunnel->i_seqno &&
 		     (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
-			tunnel->dev->stats.rx_fifo_errors++;
-			tunnel->dev->stats.rx_errors++;
+			DEV_STATS_INC(tunnel->dev, rx_fifo_errors);
+			DEV_STATS_INC(tunnel->dev, rx_errors);
 			goto drop;
 		}
 		tunnel->i_seqno = ntohl(tpi->seq) + 1;
@@ -824,8 +824,8 @@ static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 	/* Warning: All skb pointers will be invalidated! */
 	if (tunnel->dev->type == ARPHRD_ETHER) {
 		if (!pskb_may_pull(skb, ETH_HLEN)) {
-			tunnel->dev->stats.rx_length_errors++;
-			tunnel->dev->stats.rx_errors++;
+			DEV_STATS_INC(tunnel->dev, rx_length_errors);
+			DEV_STATS_INC(tunnel->dev, rx_errors);
 			goto drop;
 		}
 
@@ -849,8 +849,8 @@ static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 					     &ipv6h->saddr,
 					     ipv6_get_dsfield(ipv6h));
 		if (err > 1) {
-			++tunnel->dev->stats.rx_frame_errors;
-			++tunnel->dev->stats.rx_errors;
+			DEV_STATS_INC(tunnel->dev, rx_frame_errors);
+			DEV_STATS_INC(tunnel->dev, rx_errors);
 			goto drop;
 		}
 	}
@@ -1071,7 +1071,6 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
 {
 	struct ip6_tnl *t = netdev_priv(dev);
 	struct net *net = t->net;
-	struct net_device_stats *stats = &t->dev->stats;
 	struct ipv6hdr *ipv6h;
 	struct ipv6_tel_txoption opt;
 	struct dst_entry *dst = NULL, *ndst = NULL;
@@ -1166,7 +1165,7 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
 	tdev = dst->dev;
 
 	if (tdev == dev) {
-		stats->collisions++;
+		DEV_STATS_INC(dev, collisions);
 		net_warn_ratelimited("%s: Local routing loop detected!\n",
 				     t->parms.name);
 		goto tx_err_dst_release;
@@ -1265,7 +1264,7 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
 	ip6tunnel_xmit(NULL, skb, dev);
 	return 0;
 tx_err_link_failure:
-	stats->tx_carrier_errors++;
+	DEV_STATS_INC(dev, tx_carrier_errors);
 	dst_link_failure(skb);
 tx_err_dst_release:
 	dst_release(dst);
@@ -1408,7 +1407,6 @@ static netdev_tx_t
 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct ip6_tnl *t = netdev_priv(dev);
-	struct net_device_stats *stats = &t->dev->stats;
 	u8 ipproto;
 	int ret;
 
@@ -1438,8 +1436,8 @@ ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	return NETDEV_TX_OK;
 
 tx_err:
-	stats->tx_errors++;
-	stats->tx_dropped++;
+	DEV_STATS_INC(dev, tx_errors);
+	DEV_STATS_INC(dev, tx_dropped);
 	kfree_skb(skb);
 	return NETDEV_TX_OK;
 }

net/ipv6/ip6_vti.c

@@ -317,7 +317,7 @@ static int vti6_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi,
 
 		ipv6h = ipv6_hdr(skb);
 		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
-			t->dev->stats.rx_dropped++;
+			DEV_STATS_INC(t->dev, rx_dropped);
 			rcu_read_unlock();
 			goto discard;
 		}
@@ -359,8 +359,8 @@ static int vti6_rcv_cb(struct sk_buff *skb, int err)
 	dev = t->dev;
 
 	if (err) {
-		dev->stats.rx_errors++;
-		dev->stats.rx_dropped++;
+		DEV_STATS_INC(dev, rx_errors);
+		DEV_STATS_INC(dev, rx_dropped);
 
 		return 0;
 	}
@@ -446,7 +446,6 @@ static int
 vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 {
 	struct ip6_tnl *t = netdev_priv(dev);
-	struct net_device_stats *stats = &t->dev->stats;
 	struct dst_entry *dst = skb_dst(skb);
 	struct net_device *tdev;
 	struct xfrm_state *x;
@@ -506,7 +505,7 @@ vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 	tdev = dst->dev;
 
 	if (tdev == dev) {
-		stats->collisions++;
+		DEV_STATS_INC(dev, collisions);
 		net_warn_ratelimited("%s: Local routing loop detected!\n",
 				     t->parms.name);
 		goto tx_err_dst_release;
@@ -544,7 +543,7 @@ vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 
 	return 0;
 tx_err_link_failure:
-	stats->tx_carrier_errors++;
+	DEV_STATS_INC(dev, tx_carrier_errors);
 	dst_link_failure(skb);
 tx_err_dst_release:
 	dst_release(dst);
@@ -555,7 +554,6 @@ static netdev_tx_t
 vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct ip6_tnl *t = netdev_priv(dev);
-	struct net_device_stats *stats = &t->dev->stats;
 	struct flowi fl;
 	int ret;
 
@@ -591,8 +589,8 @@ vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 	return NETDEV_TX_OK;
 
 tx_err:
-	stats->tx_errors++;
-	stats->tx_dropped++;
+	DEV_STATS_INC(dev, tx_errors);
+	DEV_STATS_INC(dev, tx_dropped);
 	kfree_skb(skb);
 	return NETDEV_TX_OK;
 }

net/ipv6/ip6mr.c

@@ -608,8 +608,8 @@ static netdev_tx_t reg_vif_xmit(struct sk_buff *skb,
 	if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0)
 		goto tx_err;
 
-	dev->stats.tx_bytes += skb->len;
-	dev->stats.tx_packets++;
+	DEV_STATS_ADD(dev, tx_bytes, skb->len);
+	DEV_STATS_INC(dev, tx_packets);
 	rcu_read_lock();
 	ip6mr_cache_report(mrt, skb, READ_ONCE(mrt->mroute_reg_vif_num),
 			   MRT6MSG_WHOLEPKT);
@@ -618,7 +618,7 @@ static netdev_tx_t reg_vif_xmit(struct sk_buff *skb,
 	return NETDEV_TX_OK;
 
 tx_err:
-	dev->stats.tx_errors++;
+	DEV_STATS_INC(dev, tx_errors);
 	kfree_skb(skb);
 	return NETDEV_TX_OK;
 }
@@ -2044,8 +2044,8 @@ static int ip6mr_forward2(struct net *net, struct mr_table *mrt,
 	if (vif->flags & MIFF_REGISTER) {
 		WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
 		WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
-		vif_dev->stats.tx_bytes += skb->len;
-		vif_dev->stats.tx_packets++;
+		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
+		DEV_STATS_INC(vif_dev, tx_packets);
 		ip6mr_cache_report(mrt, skb, vifi, MRT6MSG_WHOLEPKT);
 		goto out_free;
 	}