bridge: 64bit rx/tx counters

Use u64_stats_sync infrastructure to provide 64bit rx/tx
counters even on 32bit hosts.

It is safe to use a single u64_stats_sync for rx and tx,
because BH is disabled on both, and we use per_cpu data.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 23 insertions, 13 deletions

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 6f3a9279be30..edf639e96281 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -38,8 +38,10 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
         }
 #endif
 
+        u64_stats_update_begin(&brstats->syncp);
         brstats->tx_packets++;
         brstats->tx_bytes += skb->len;
+        u64_stats_update_end(&brstats->syncp);
 
         BR_INPUT_SKB_CB(skb)->brdev = dev;
 
@@ -96,21 +98,25 @@ static int br_dev_stop(struct net_device *dev)
         return 0;
 }
 
-static struct net_device_stats *br_get_stats(struct net_device *dev)
+static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev)
 {
         struct net_bridge *br = netdev_priv(dev);
-        struct net_device_stats *stats = &dev->stats;
-        struct br_cpu_netstats sum = { 0 };
+        struct rtnl_link_stats64 *stats = &dev->stats64;
+        struct br_cpu_netstats tmp, sum = { 0 };
         unsigned int cpu;
 
         for_each_possible_cpu(cpu) {
+                unsigned int start;
                 const struct br_cpu_netstats *bstats
                         = per_cpu_ptr(br->stats, cpu);
-
-                sum.tx_bytes   += bstats->tx_bytes;
-                sum.tx_packets += bstats->tx_packets;
-                sum.rx_bytes   += bstats->rx_bytes;
-                sum.rx_packets += bstats->rx_packets;
+                do {
+                        start = u64_stats_fetch_begin(&bstats->syncp);
+                        memcpy(&tmp, bstats, sizeof(tmp));
+                } while (u64_stats_fetch_retry(&bstats->syncp, start));
+                sum.tx_bytes   += tmp.tx_bytes;
+                sum.tx_packets += tmp.tx_packets;
+                sum.rx_bytes   += tmp.rx_bytes;
+                sum.rx_packets += tmp.rx_packets;
         }
 
         stats->tx_bytes   = sum.tx_bytes;
@@ -300,7 +306,7 @@ static const struct net_device_ops br_netdev_ops = {
         .ndo_open                = br_dev_open,
         .ndo_stop                = br_dev_stop,
         .ndo_start_xmit          = br_dev_xmit,
-        .ndo_get_stats           = br_get_stats,
+        .ndo_get_stats64         = br_get_stats64,
         .ndo_set_mac_address     = br_set_mac_address,
         .ndo_set_multicast_list  = br_dev_set_multicast_list,
         .ndo_change_mtu          = br_change_mtu,
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index f076c9d79d5e..5fc1c5b1c360 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -27,8 +27,10 @@ static int br_pass_frame_up(struct sk_buff *skb)
         struct net_bridge *br = netdev_priv(brdev);
         struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
 
+        u64_stats_update_begin(&brstats->syncp);
         brstats->rx_packets++;
         brstats->rx_bytes += skb->len;
+        u64_stats_update_end(&brstats->syncp);
 
         indev = skb->dev;
         skb->dev = brdev;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 07cf57b373fe..3f0678fd1fd0 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -16,6 +16,7 @@
 #include <linux/netdevice.h>
 #include <linux/if_bridge.h>
 #include <linux/netpoll.h>
+#include <linux/u64_stats_sync.h>
 #include <net/route.h>
 
 #define BR_HASH_BITS 8
@@ -156,10 +157,11 @@ struct net_bridge_port
 #define br_port_exists(dev) (dev->priv_flags & IFF_BRIDGE_PORT)
 
 struct br_cpu_netstats {
-        unsigned long   rx_packets;
-        unsigned long   rx_bytes;
-        unsigned long   tx_packets;
-        unsigned long   tx_bytes;
+        u64                     rx_packets;
+        u64                     rx_bytes;
+        u64                     tx_packets;
+        u64                     tx_bytes;
+        struct u64_stats_sync   syncp;
 };
 
 struct net_bridge