netpoll: add net device refcount tracker to struct netpoll

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/netconsole.c

@@ -721,7 +721,7 @@ static int netconsole_netdev_event(struct notifier_block *this,
 				__netpoll_cleanup(&nt->np);
 
 				spin_lock_irqsave(&target_list_lock, flags);
-				dev_put(nt->np.dev);
+				dev_put_track(nt->np.dev, &nt->np.dev_tracker);
 				nt->np.dev = NULL;
 				nt->enabled = false;
 				stopped = true;

include/linux/netpoll.h

@@ -24,6 +24,7 @@ union inet_addr {
 
 struct netpoll {
 	struct net_device *dev;
+	netdevice_tracker dev_tracker;
 	char dev_name[IFNAMSIZ];
 	const char *name;
 

net/core/netpoll.c

@@ -776,7 +776,7 @@ int netpoll_setup(struct netpoll *np)
 	err = __netpoll_setup(np, ndev);
 	if (err)
 		goto put;
-
+	netdev_tracker_alloc(ndev, &np->dev_tracker, GFP_KERNEL);
 	rtnl_unlock();
 	return 0;
 
@@ -853,7 +853,7 @@ void netpoll_cleanup(struct netpoll *np)
 	if (!np->dev)
 		goto out;
 	__netpoll_cleanup(np);
-	dev_put(np->dev);
+	dev_put_track(np->dev, &np->dev_tracker);
 	np->dev = NULL;
 out:
 	rtnl_unlock();