[NETNS]: Add netns refcnt debug for network devices.

dev_set_net is called for
- just allocated devices
- devices moving from one namespace to another
release_net has proper check inside to distinguish these cases.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 8b17ed40dea2..7c1d4466583b 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -758,7 +758,8 @@ static inline
 void dev_net_set(struct net_device *dev, struct net *net)
 {
 #ifdef CONFIG_NET_NS
-        dev->nd_net = net;
+        release_net(dev->nd_net);
+        dev->nd_net = hold_net(net);
 #endif
 }