net: adopt u64_stats_t in struct pcpu_sw_netstats

As explained in commit 316580b69d0a ("u64_stats: provide u64_stats_t type")
we should use u64_stats_t and related accessors to avoid load/store tearing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 37 insertions, 33 deletions

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index bb01776d2d88..1ef14a099c6b 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1770,10 +1770,10 @@ static int br_fill_linkxstats(struct sk_buff *skb,
 			if (v->vid == pvid)
 				vxi.flags |= BRIDGE_VLAN_INFO_PVID;
 			br_vlan_get_stats(v, &stats);
-			vxi.rx_bytes = stats.rx_bytes;
-			vxi.rx_packets = stats.rx_packets;
-			vxi.tx_bytes = stats.tx_bytes;
-			vxi.tx_packets = stats.tx_packets;
+			vxi.rx_bytes = u64_stats_read(&stats.rx_bytes);
+			vxi.rx_packets = u64_stats_read(&stats.rx_packets);
+			vxi.tx_bytes = u64_stats_read(&stats.tx_bytes);
+			vxi.tx_packets = u64_stats_read(&stats.tx_packets);
 
 			if (nla_put(skb, BRIDGE_XSTATS_VLAN, sizeof(vxi), &vxi))
 				goto nla_put_failure;
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 0f5e75ccac79..6e53dc991409 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -505,8 +505,8 @@ struct sk_buff *br_handle_vlan(struct net_bridge *br,
 	if (br_opt_get(br, BROPT_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_add(&stats->tx_bytes, skb->len);
+		u64_stats_inc(&stats->tx_packets);
 		u64_stats_update_end(&stats->syncp);
 	}
 
@@ -624,8 +624,8 @@ static bool __allowed_ingress(const struct net_bridge *br,
 	if (br_opt_get(br, BROPT_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_add(&stats->rx_bytes, skb->len);
+		u64_stats_inc(&stats->rx_packets);
 		u64_stats_update_end(&stats->syncp);
 	}
 
@@ -1379,16 +1379,16 @@ void br_vlan_get_stats(const struct net_bridge_vlan *v,
 		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;
+			rxpackets = u64_stats_read(&cpu_stats->rx_packets);
+			rxbytes = u64_stats_read(&cpu_stats->rx_bytes);
+			txbytes = u64_stats_read(&cpu_stats->tx_bytes);
+			txpackets = u64_stats_read(&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;
+		u64_stats_add(&stats->rx_packets, rxpackets);
+		u64_stats_add(&stats->rx_bytes, rxbytes);
+		u64_stats_add(&stats->tx_bytes, txbytes);
+		u64_stats_add(&stats->tx_packets, txpackets);
 	}
 }
 
@@ -1779,14 +1779,18 @@ static bool br_vlan_stats_fill(struct sk_buff *skb,
 		return false;
 
 	br_vlan_get_stats(v, &stats);
-	if (nla_put_u64_64bit(skb, BRIDGE_VLANDB_STATS_RX_BYTES, stats.rx_bytes,
+	if (nla_put_u64_64bit(skb, BRIDGE_VLANDB_STATS_RX_BYTES,
+			      u64_stats_read(&stats.rx_bytes),
 			      BRIDGE_VLANDB_STATS_PAD) ||
 	    nla_put_u64_64bit(skb, BRIDGE_VLANDB_STATS_RX_PACKETS,
-			      stats.rx_packets, BRIDGE_VLANDB_STATS_PAD) ||
-	    nla_put_u64_64bit(skb, BRIDGE_VLANDB_STATS_TX_BYTES, stats.tx_bytes,
+			      u64_stats_read(&stats.rx_packets),
+			      BRIDGE_VLANDB_STATS_PAD) ||
+	    nla_put_u64_64bit(skb, BRIDGE_VLANDB_STATS_TX_BYTES,
+			      u64_stats_read(&stats.tx_bytes),
 			      BRIDGE_VLANDB_STATS_PAD) ||
 	    nla_put_u64_64bit(skb, BRIDGE_VLANDB_STATS_TX_PACKETS,
-			      stats.tx_packets, BRIDGE_VLANDB_STATS_PAD))
+			      u64_stats_read(&stats.tx_packets),
+			      BRIDGE_VLANDB_STATS_PAD))
 		goto out_err;
 
 	nla_nest_end(skb, nest);
diff --git a/net/core/dev.c b/net/core/dev.c
index c9d96b85a825..511cf5d3aade 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -10459,23 +10459,23 @@ void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
 	int cpu;
 
 	for_each_possible_cpu(cpu) {
+		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
 		const struct pcpu_sw_netstats *stats;
-		struct pcpu_sw_netstats tmp;
 		unsigned int start;
 
 		stats = per_cpu_ptr(netstats, cpu);
 		do {
 			start = u64_stats_fetch_begin_irq(&stats->syncp);
-			tmp.rx_packets = stats->rx_packets;
-			tmp.rx_bytes   = stats->rx_bytes;
-			tmp.tx_packets = stats->tx_packets;
-			tmp.tx_bytes   = stats->tx_bytes;
+			rx_packets = u64_stats_read(&stats->rx_packets);
+			rx_bytes   = u64_stats_read(&stats->rx_bytes);
+			tx_packets = u64_stats_read(&stats->tx_packets);
+			tx_bytes   = u64_stats_read(&stats->tx_bytes);
 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
 
-		s->rx_packets += tmp.rx_packets;
-		s->rx_bytes   += tmp.rx_bytes;
-		s->tx_packets += tmp.tx_packets;
-		s->tx_bytes   += tmp.tx_bytes;
+		s->rx_packets += rx_packets;
+		s->rx_bytes   += rx_bytes;
+		s->tx_packets += tx_packets;
+		s->tx_bytes   += tx_bytes;
 	}
 }
 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 801a5d445833..2e1ac638d135 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -935,10 +935,10 @@ static void dsa_slave_get_ethtool_stats(struct net_device *dev,
 		s = per_cpu_ptr(dev->tstats, i);
 		do {
 			start = u64_stats_fetch_begin_irq(&s->syncp);
-			tx_packets = s->tx_packets;
-			tx_bytes = s->tx_bytes;
-			rx_packets = s->rx_packets;
-			rx_bytes = s->rx_bytes;
+			tx_packets = u64_stats_read(&s->tx_packets);
+			tx_bytes = u64_stats_read(&s->tx_bytes);
+			rx_packets = u64_stats_read(&s->rx_packets);
+			rx_bytes = u64_stats_read(&s->rx_bytes);
 		} while (u64_stats_fetch_retry_irq(&s->syncp, start));
 		data[0] += tx_packets;
 		data[1] += tx_bytes;