ipv4: add net device refcount tracker to struct in_device

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

include/linux/inetdevice.h

@@ -24,6 +24,8 @@ struct ipv4_devconf {
 
 struct in_device {
 	struct net_device	*dev;
+	netdevice_tracker	dev_tracker;
+
 	refcount_t		refcnt;
 	int			dead;
 	struct in_ifaddr	__rcu *ifa_list;/* IP ifaddr chain		*/

net/ipv4/devinet.c

@@ -243,7 +243,7 @@ void in_dev_finish_destroy(struct in_device *idev)
 #ifdef NET_REFCNT_DEBUG
 	pr_debug("%s: %p=%s\n", __func__, idev, dev ? dev->name : "NIL");
 #endif
-	dev_put(dev);
+	dev_put_track(dev, &idev->dev_tracker);
 	if (!idev->dead)
 		pr_err("Freeing alive in_device %p\n", idev);
 	else
@@ -271,7 +271,7 @@ static struct in_device *inetdev_init(struct net_device *dev)
 	if (IPV4_DEVCONF(in_dev->cnf, FORWARDING))
 		dev_disable_lro(dev);
 	/* Reference in_dev->dev */
-	dev_hold(dev);
+	dev_hold_track(dev, &in_dev->dev_tracker, GFP_KERNEL);
 	/* Account for reference dev->ip_ptr (below) */
 	refcount_set(&in_dev->refcnt, 1);