net: linkwatch: allow vlans to get carrier changes faster
There is a time-lag of IFF_RUNNING flag consistency between vlan and
real devices when the real devices are in problem such as link or cable
broken.
This leads to a degradation of Availability such as a delay of failover
in HA systems using vlan since the detection of the problem at real
device is delayed.
We can avoid the linkwatch delay (~1 sec) for devices linked to another
ones, since delay is already done for the realdev.
Based on a previous patch from Mitsuo Hayasaka
Reported-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Patrick McHardy <kaber@trash.net>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Tom Herbert <therbert@google.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Jesse Gross <jesse@nicira.com>
Tested-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/link_watch.c b/net/core/link_watch.c
index 357bd4e..c3519c6 100644
--- a/net/core/link_watch.c
+++ b/net/core/link_watch.c
@@ -78,8 +78,13 @@
static bool linkwatch_urgent_event(struct net_device *dev)
{
- return netif_running(dev) && netif_carrier_ok(dev) &&
- qdisc_tx_changing(dev);
+ if (!netif_running(dev))
+ return false;
+
+ if (dev->ifindex != dev->iflink)
+ return true;
+
+ return netif_carrier_ok(dev) && qdisc_tx_changing(dev);
}