ipv6: add net device refcount tracker to struct inet6_dev

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

include/net/if_inet6.h

@@ -160,6 +160,7 @@ struct ipv6_devstat {
 
 struct inet6_dev {
 	struct net_device	*dev;
+	netdevice_tracker	dev_tracker;
 
 	struct list_head	addr_list;
 

net/ipv6/addrconf.c

@@ -405,13 +405,13 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
 	if (ndev->cnf.forwarding)
 		dev_disable_lro(dev);
 	/* We refer to the device */
-	dev_hold(dev);
+	dev_hold_track(dev, &ndev->dev_tracker, GFP_KERNEL);
 
 	if (snmp6_alloc_dev(ndev) < 0) {
 		netdev_dbg(dev, "%s: cannot allocate memory for statistics\n",
 			   __func__);
 		neigh_parms_release(&nd_tbl, ndev->nd_parms);
-		dev_put(dev);
+		dev_put_track(dev, &ndev->dev_tracker);
 		kfree(ndev);
 		return ERR_PTR(err);
 	}

net/ipv6/addrconf_core.c

@@ -263,7 +263,7 @@ void in6_dev_finish_destroy(struct inet6_dev *idev)
 #ifdef NET_REFCNT_DEBUG
 	pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
 #endif
-	dev_put(dev);
+	dev_put_track(dev, &idev->dev_tracker);
 	if (!idev->dead) {
 		pr_warn("Freeing alive inet6 device %p\n", idev);
 		return;