net_sched: make dev_trans_start return vlan's real dev trans_start

Vlan devices are LLTX and don't update their own trans_start, so if
dev_trans_start has to be called with a vlan device then 0 or a stale
value will be returned. Currently the bonding is the only such user, and
it's needed for proper arp monitoring when the slaves are vlans.
Fix this by extracting the vlan's real device trans_start.

Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 1 deletions

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 4626cef4b76e..eeb8276d7a89 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -25,6 +25,7 @@
 #include <linux/rcupdate.h>
 #include <linux/list.h>
 #include <linux/slab.h>
+#include <linux/if_vlan.h>
 #include <net/sch_generic.h>
 #include <net/pkt_sched.h>
 #include <net/dst.h>
@@ -207,15 +208,19 @@ void __qdisc_run(struct Qdisc *q)
 
 unsigned long dev_trans_start(struct net_device *dev)
 {
-        unsigned long val, res = dev->trans_start;
+        unsigned long val, res;
         unsigned int i;
 
+        if (is_vlan_dev(dev))
+                dev = vlan_dev_real_dev(dev);
+        res = dev->trans_start;
         for (i = 0; i < dev->num_tx_queues; i++) {
                 val = netdev_get_tx_queue(dev, i)->trans_start;
                 if (val && time_after(val, res))
                         res = val;
         }
         dev->trans_start = res;
+
         return res;
 }
 EXPORT_SYMBOL(dev_trans_start);