netdev-linux: Fix stats for ovs internal device.

There is no need to retrieve linux system stats for internal devices
as all relevant stats for virtual device like internal device are
already reported by OVS over vport-stats. As a result it also fixes
error stats for internal-devices as they are not counted twice.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>

diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
index 6ad08520050307f64aabf784e2dbaf86e862091d..5c322ca088c539a9d5203b3c8ea43bdd26c4febc 100644 (file)
--- a/lib/netdev-linux.c
+++ b/lib/netdev-linux.c
@@ -114,7 +114,7 @@ enum {
     VALID_IN6               = 1 << 3,
     VALID_MTU               = 1 << 4,
     VALID_POLICING          = 1 << 5,
-    VALID_HAVE_VPORT_STATS  = 1 << 6
+    VALID_VPORT_STAT_ERROR  = 1 << 6
 };
 
 struct tap_state {
@@ -372,7 +372,8 @@ struct netdev_dev_linux {
     long long int carrier_resets;
     uint32_t kbits_rate;        /* Policing data. */
     uint32_t kbits_burst;
-    bool have_vport_stats;
+    int vport_stats_error;      /* Cached error code from vport_get_stats().
+                                   0 or an errno value. */
     struct tc *tc;
 
     union {
@@ -1236,8 +1237,8 @@ get_stats_via_vport(const struct netdev *netdev_,
     struct netdev_dev_linux *netdev_dev =
                                 netdev_dev_linux_cast(netdev_get_dev(netdev_));
 
-    if (netdev_dev->have_vport_stats ||
-        !(netdev_dev->cache_valid & VALID_HAVE_VPORT_STATS)) {
+    if (!netdev_dev->vport_stats_error ||
+        !(netdev_dev->cache_valid & VALID_VPORT_STAT_ERROR)) {
         int error;
 
         error = netdev_vport_get_stats(netdev_, stats);
@@ -1245,8 +1246,8 @@ get_stats_via_vport(const struct netdev *netdev_,
             VLOG_WARN_RL(&rl, "%s: obtaining netdev stats via vport failed "
                          "(%s)", netdev_get_name(netdev_), strerror(error));
         }
-        netdev_dev->have_vport_stats = !error;
-        netdev_dev->cache_valid |= VALID_HAVE_VPORT_STATS;
+        netdev_dev->vport_stats_error = error;
+        netdev_dev->cache_valid |= VALID_VPORT_STAT_ERROR;
     }
 }
 
@@ -1295,14 +1296,14 @@ netdev_linux_get_stats(const struct netdev *netdev_,
     error = netdev_linux_sys_get_stats(netdev_, &dev_stats);
 
     if (error) {
-        if (!netdev_dev->have_vport_stats) {
+        if (netdev_dev->vport_stats_error) {
             return error;
         } else {
             return 0;
         }
     }
 
-    if (!netdev_dev->have_vport_stats) {
+    if (netdev_dev->vport_stats_error) {
         /* stats not available from OVS then use ioctl stats. */
         *stats = dev_stats;
     } else {
@@ -1330,7 +1331,7 @@ netdev_linux_get_stats(const struct netdev *netdev_,
 /* Retrieves current device stats for 'netdev-tap' netdev or
  * netdev-internal. */
 static int
-netdev_pseudo_get_stats(const struct netdev *netdev_,
+netdev_tap_get_stats(const struct netdev *netdev_,
                         struct netdev_stats *stats)
 {
     struct netdev_dev_linux *netdev_dev =
@@ -1342,7 +1343,7 @@ netdev_pseudo_get_stats(const struct netdev *netdev_,
 
     error = netdev_linux_sys_get_stats(netdev_, &dev_stats);
     if (error) {
-        if (!netdev_dev->have_vport_stats) {
+        if (netdev_dev->vport_stats_error) {
             return error;
         } else {
             return 0;
@@ -1355,7 +1356,7 @@ netdev_pseudo_get_stats(const struct netdev *netdev_,
      * them back here. This does not apply if we are getting stats from the
      * vport layer because it always tracks stats from the perspective of the
      * switch. */
-    if (!netdev_dev->have_vport_stats) {
+    if (netdev_dev->vport_stats_error) {
         *stats = dev_stats;
         swap_uint64(&stats->rx_packets, &stats->tx_packets);
         swap_uint64(&stats->rx_bytes, &stats->tx_bytes);
@@ -1385,6 +1386,17 @@ netdev_pseudo_get_stats(const struct netdev *netdev_,
     return 0;
 }
 
+static int
+netdev_internal_get_stats(const struct netdev *netdev_,
+                          struct netdev_stats *stats)
+{
+    struct netdev_dev_linux *netdev_dev =
+                                netdev_dev_linux_cast(netdev_get_dev(netdev_));
+
+    get_stats_via_vport(netdev_, stats);
+    return netdev_dev->vport_stats_error;
+}
+
 /* Stores the features supported by 'netdev' into each of '*current',
  * '*advertised', '*supported', and '*peer' that are non-null.  Each value is a
  * bitmap of "enum ofp_port_features" bits, in host byte order.  Returns 0 if
@@ -2302,14 +2314,14 @@ const struct netdev_class netdev_tap_class =
     NETDEV_LINUX_CLASS(
         "tap",
         netdev_linux_create_tap,
-        netdev_pseudo_get_stats,
+        netdev_tap_get_stats,
         NULL);                  /* set_stats */
 
 const struct netdev_class netdev_internal_class =
     NETDEV_LINUX_CLASS(
         "internal",
         netdev_linux_create,
-        netdev_pseudo_get_stats,
+        netdev_internal_get_stats,
         netdev_vport_set_stats);
 \f
 /* HTB traffic control class. */