net-sysfs: expose number of carrier on/off changes
This allows to monitor carrier on/off transitions and detect link
flapping issues:
- new /sys/class/net/X/carrier_changes
- new rtnetlink IFLA_CARRIER_CHANGES (getlink)
Tested:
- grep . /sys/class/net/*/carrier_changes
+ ip link set dev X down/up
+ plug/unplug cable
- updated iproute2: prints IFLA_CARRIER_CHANGES
- iproute2 20121211-2 (debian): unchanged behavior
Signed-off-by: David Decotigny <decot@googlers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index e82e43b..e1543b0 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -310,6 +310,7 @@
if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
if (dev->reg_state == NETREG_UNINITIALIZED)
return;
+ atomic_inc(&dev->carrier_changes);
linkwatch_fire_event(dev);
if (netif_running(dev))
__netdev_watchdog_up(dev);
@@ -328,6 +329,7 @@
if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
if (dev->reg_state == NETREG_UNINITIALIZED)
return;
+ atomic_inc(&dev->carrier_changes);
linkwatch_fire_event(dev);
}
}