ipmr, ip6mr: add net device refcount tracker to struct vif_device

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

include/linux/mroute_base.h

@@ -12,6 +12,7 @@
 /**
  * struct vif_device - interface representor for multicast routing
  * @dev: network device being used
+ * @dev_tracker: refcount tracker for @dev reference
  * @bytes_in: statistic; bytes ingressing
  * @bytes_out: statistic; bytes egresing
  * @pkt_in: statistic; packets ingressing
@@ -26,6 +27,7 @@
  */
 struct vif_device {
 	struct net_device *dev;
+	netdevice_tracker dev_tracker;
 	unsigned long bytes_in, bytes_out;
 	unsigned long pkt_in, pkt_out;
 	unsigned long rate_limit;

net/ipv4/ipmr.c

@@ -696,7 +696,7 @@ static int vif_delete(struct mr_table *mrt, int vifi, int notify,
 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
 		unregister_netdevice_queue(dev, head);
 
-	dev_put(dev);
+	dev_put_track(dev, &v->dev_tracker);
 	return 0;
 }
 
@@ -896,6 +896,7 @@ static int vif_add(struct net *net, struct mr_table *mrt,
 	/* And finish update writing critical data */
 	write_lock_bh(&mrt_lock);
 	v->dev = dev;
+	netdev_tracker_alloc(dev, &v->dev_tracker, GFP_ATOMIC);
 	if (v->flags & VIFF_REGISTER)
 		mrt->mroute_reg_vif_num = vifi;
 	if (vifi+1 > mrt->maxvif)

net/ipv6/ip6mr.c

@@ -746,7 +746,7 @@ static int mif6_delete(struct mr_table *mrt, int vifi, int notify,
 	if ((v->flags & MIFF_REGISTER) && !notify)
 		unregister_netdevice_queue(dev, head);
 
-	dev_put(dev);
+	dev_put_track(dev, &v->dev_tracker);
 	return 0;
 }
 
@@ -919,6 +919,7 @@ static int mif6_add(struct net *net, struct mr_table *mrt,
 	/* And finish update writing critical data */
 	write_lock_bh(&mrt_lock);
 	v->dev = dev;
+	netdev_tracker_alloc(dev, &v->dev_tracker, GFP_ATOMIC);
 #ifdef CONFIG_IPV6_PIMSM_V2
 	if (v->flags & MIFF_REGISTER)
 		mrt->mroute_reg_vif_num = vifi;