net: Enable 64-bit net device statistics on 32-bit architectures

Use struct rtnl_link_stats64 as the statistics structure.

On 32-bit architectures, insert 32 bits of padding after/before each
field of struct net_device_stats to make its layout compatible with
struct rtnl_link_stats64.  Add an anonymous union in net_device; move
stats into the union and add struct rtnl_link_stats64 stats64.

Add net_device_ops::ndo_get_stats64, implementations of which will
return a pointer to struct rtnl_link_stats64.  Drivers that implement
this operation must not update the structure asynchronously.

Change dev_get_stats() to call ndo_get_stats64 if available, and to
return a pointer to struct rtnl_link_stats64.  Change callers of
dev_get_stats() accordingly.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 27 insertions, 23 deletions

diff --git a/net/8021q/vlanproc.c b/net/8021q/vlanproc.c
index afead353e215..df56f5ce887c 100644
--- a/net/8021q/vlanproc.c
+++ b/net/8021q/vlanproc.c
@@ -278,8 +278,9 @@ static int vlandev_seq_show(struct seq_file *seq, void *offset)
 {
         struct net_device *vlandev = (struct net_device *) seq->private;
         const struct vlan_dev_info *dev_info = vlan_dev_info(vlandev);
-        const struct net_device_stats *stats;
+        const struct rtnl_link_stats64 *stats;
         static const char fmt[] = "%30s %12lu\n";
+        static const char fmt64[] = "%30s %12llu\n";
         int i;
 
         if (!is_vlan_dev(vlandev))
@@ -291,12 +292,12 @@ static int vlandev_seq_show(struct seq_file *seq, void *offset)
                    vlandev->name, dev_info->vlan_id,
                    (int)(dev_info->flags & 1), vlandev->priv_flags);
 
-        seq_printf(seq, fmt, "total frames received", stats->rx_packets);
-        seq_printf(seq, fmt, "total bytes received", stats->rx_bytes);
-        seq_printf(seq, fmt, "Broadcast/Multicast Rcvd", stats->multicast);
+        seq_printf(seq, fmt64, "total frames received", stats->rx_packets);
+        seq_printf(seq, fmt64, "total bytes received", stats->rx_bytes);
+        seq_printf(seq, fmt64, "Broadcast/Multicast Rcvd", stats->multicast);
         seq_puts(seq, "\n");
-        seq_printf(seq, fmt, "total frames transmitted", stats->tx_packets);
-        seq_printf(seq, fmt, "total bytes transmitted", stats->tx_bytes);
+        seq_printf(seq, fmt64, "total frames transmitted", stats->tx_packets);
+        seq_printf(seq, fmt64, "total bytes transmitted", stats->tx_bytes);
         seq_printf(seq, fmt, "total headroom inc",
                    dev_info->cnt_inc_headroom_on_tx);
         seq_printf(seq, fmt, "total encap on xmit",
diff --git a/net/core/dev.c b/net/core/dev.c
index 277844901ce3..a1abc10db08a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3701,10 +3701,10 @@ void dev_seq_stop(struct seq_file *seq, void *v)
 
 static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
 {
-        const struct net_device_stats *stats = dev_get_stats(dev);
+        const struct rtnl_link_stats64 *stats = dev_get_stats(dev);
 
-        seq_printf(seq, "%6s: %7lu %7lu %4lu %4lu %4lu %5lu %10lu %9lu "
-                   "%8lu %7lu %4lu %4lu %4lu %5lu %7lu %10lu\n",
+        seq_printf(seq, "%6s: %7llu %7llu %4llu %4llu %4llu %5llu %10llu %9llu "
+                   "%8llu %7llu %4llu %4llu %4llu %5llu %7llu %10llu\n",
                    dev->name, stats->rx_bytes, stats->rx_packets,
                    stats->rx_errors,
                    stats->rx_dropped + stats->rx_missed_errors,
@@ -5281,18 +5281,21 @@ EXPORT_SYMBOL(dev_txq_stats_fold);
  *      @dev: device to get statistics from
  *
  *      Get network statistics from device. The device driver may provide
- *      its own method by setting dev->netdev_ops->get_stats; otherwise
- *      the internal statistics structure is used.
+ *      its own method by setting dev->netdev_ops->get_stats64 or
+ *      dev->netdev_ops->get_stats; otherwise the internal statistics
+ *      structure is used.
  */
-const struct net_device_stats *dev_get_stats(struct net_device *dev)
+const struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev)
 {
         const struct net_device_ops *ops = dev->netdev_ops;
 
+        if (ops->ndo_get_stats64)
+                return ops->ndo_get_stats64(dev);
         if (ops->ndo_get_stats)
-                return ops->ndo_get_stats(dev);
+                return (struct rtnl_link_stats64 *)ops->ndo_get_stats(dev);
 
         dev_txq_stats_fold(dev, &dev->stats);
-        return &dev->stats;
+        return &dev->stats64;
 }
 EXPORT_SYMBOL(dev_get_stats);
 
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 99e7052d7323..ea3bb4c3b87d 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -29,6 +29,7 @@ static const char fmt_hex[] = "%#x\n";
 static const char fmt_long_hex[] = "%#lx\n";
 static const char fmt_dec[] = "%d\n";
 static const char fmt_ulong[] = "%lu\n";
+static const char fmt_u64[] = "%llu\n";
 
 static inline int dev_isalive(const struct net_device *dev)
 {
@@ -324,14 +325,13 @@ static ssize_t netstat_show(const struct device *d,
         struct net_device *dev = to_net_dev(d);
         ssize_t ret = -EINVAL;
 
-        WARN_ON(offset > sizeof(struct net_device_stats) ||
-                        offset % sizeof(unsigned long) != 0);
+        WARN_ON(offset > sizeof(struct rtnl_link_stats64) ||
+                        offset % sizeof(u64) != 0);
 
         read_lock(&dev_base_lock);
         if (dev_isalive(dev)) {
-                const struct net_device_stats *stats = dev_get_stats(dev);
-                ret = sprintf(buf, fmt_ulong,
-                              *(unsigned long *)(((u8 *) stats) + offset));
+                const struct rtnl_link_stats64 *stats = dev_get_stats(dev);
+                ret = sprintf(buf, fmt_u64, *(u64 *)(((u8 *) stats) + offset));
         }
         read_unlock(&dev_base_lock);
         return ret;
@@ -343,7 +343,7 @@ static ssize_t show_##name(struct device *d,				\
                            struct device_attribute *attr, char *buf)    \
 {                                                                       \
         return netstat_show(d, attr, buf,                               \
-                            offsetof(struct net_device_stats, name));   \
+                            offsetof(struct rtnl_link_stats64, name));  \
 }                                                                       \
 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 1a2af24e9e3d..e645778e9b7e 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -579,7 +579,7 @@ static unsigned int rtnl_dev_combine_flags(const struct net_device *dev,
 }
 
 static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
-                                 const struct net_device_stats *b)
+                                 const struct rtnl_link_stats64 *b)
 {
         a->rx_packets = b->rx_packets;
         a->tx_packets = b->tx_packets;
@@ -610,7 +610,7 @@ static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
         a->tx_compressed = b->tx_compressed;
 }
 
-static void copy_rtnl_link_stats64(void *v, const struct net_device_stats *b)
+static void copy_rtnl_link_stats64(void *v, const struct rtnl_link_stats64 *b)
 {
         struct rtnl_link_stats64 a;
 
@@ -791,7 +791,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
 {
         struct ifinfomsg *ifm;
         struct nlmsghdr *nlh;
-        const struct net_device_stats *stats;
+        const struct rtnl_link_stats64 *stats;
         struct nlattr *attr;
 
         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags);