ipvlan: adopt u64_stats_t

As explained in commit 316580b6 ("u64_stats: provide u64_stats_t type")
we should use u64_stats_t and related accessors to avoid load/store tearing.

Add READ_ONCE() when reading rx_errs & tx_drps.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ipvlan/ipvlan.h

@@ -47,11 +47,11 @@ typedef enum {
 } ipvl_hdr_type;
 
 struct ipvl_pcpu_stats {
-	u64			rx_pkts;
-	u64			rx_bytes;
-	u64			rx_mcast;
-	u64			tx_pkts;
-	u64			tx_bytes;
+	u64_stats_t		rx_pkts;
+	u64_stats_t		rx_bytes;
+	u64_stats_t		rx_mcast;
+	u64_stats_t		tx_pkts;
+	u64_stats_t		tx_bytes;
 	struct u64_stats_sync	syncp;
 	u32			rx_errs;
 	u32			tx_drps;

drivers/net/ipvlan/ipvlan_core.c

@@ -19,10 +19,10 @@ void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
 
 		pcptr = this_cpu_ptr(ipvlan->pcpu_stats);
 		u64_stats_update_begin(&pcptr->syncp);
-		pcptr->rx_pkts++;
-		pcptr->rx_bytes += len;
+		u64_stats_inc(&pcptr->rx_pkts);
+		u64_stats_add(&pcptr->rx_bytes, len);
 		if (mcast)
-			pcptr->rx_mcast++;
+			u64_stats_inc(&pcptr->rx_mcast);
 		u64_stats_update_end(&pcptr->syncp);
 	} else {
 		this_cpu_inc(ipvlan->pcpu_stats->rx_errs);

drivers/net/ipvlan/ipvlan_main.c

@@ -224,8 +224,8 @@ static netdev_tx_t ipvlan_start_xmit(struct sk_buff *skb,
 		pcptr = this_cpu_ptr(ipvlan->pcpu_stats);
 
 		u64_stats_update_begin(&pcptr->syncp);
-		pcptr->tx_pkts++;
-		pcptr->tx_bytes += skblen;
+		u64_stats_inc(&pcptr->tx_pkts);
+		u64_stats_add(&pcptr->tx_bytes, skblen);
 		u64_stats_update_end(&pcptr->syncp);
 	} else {
 		this_cpu_inc(ipvlan->pcpu_stats->tx_drps);
@@ -300,11 +300,11 @@ static void ipvlan_get_stats64(struct net_device *dev,
 			pcptr = per_cpu_ptr(ipvlan->pcpu_stats, idx);
 			do {
 				strt= u64_stats_fetch_begin_irq(&pcptr->syncp);
-				rx_pkts = pcptr->rx_pkts;
-				rx_bytes = pcptr->rx_bytes;
-				rx_mcast = pcptr->rx_mcast;
-				tx_pkts = pcptr->tx_pkts;
-				tx_bytes = pcptr->tx_bytes;
+				rx_pkts = u64_stats_read(&pcptr->rx_pkts);
+				rx_bytes = u64_stats_read(&pcptr->rx_bytes);
+				rx_mcast = u64_stats_read(&pcptr->rx_mcast);
+				tx_pkts = u64_stats_read(&pcptr->tx_pkts);
+				tx_bytes = u64_stats_read(&pcptr->tx_bytes);
 			} while (u64_stats_fetch_retry_irq(&pcptr->syncp,
 							   strt));
 
@@ -315,8 +315,8 @@ static void ipvlan_get_stats64(struct net_device *dev,
 			s->tx_bytes += tx_bytes;
 
 			/* u32 values are updated without syncp protection. */
-			rx_errs += pcptr->rx_errs;
-			tx_drps += pcptr->tx_drps;
+			rx_errs += READ_ONCE(pcptr->rx_errs);
+			tx_drps += READ_ONCE(pcptr->tx_drps);
 		}
 		s->rx_errors = rx_errs;
 		s->rx_dropped = rx_errs;