inet: add net device refcount tracker to struct fib_nh_common

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

include/net/ip_fib.h

@@ -79,6 +79,7 @@ struct fnhe_hash_bucket {
 
 struct fib_nh_common {
 	struct net_device	*nhc_dev;
+	netdevice_tracker	nhc_dev_tracker;
 	int			nhc_oif;
 	unsigned char		nhc_scope;
 	u8			nhc_family;
@@ -111,6 +112,7 @@ struct fib_nh {
 	int			nh_saddr_genid;
 #define fib_nh_family		nh_common.nhc_family
 #define fib_nh_dev		nh_common.nhc_dev
+#define fib_nh_dev_tracker	nh_common.nhc_dev_tracker
 #define fib_nh_oif		nh_common.nhc_oif
 #define fib_nh_flags		nh_common.nhc_flags
 #define fib_nh_lws		nh_common.nhc_lwtstate

net/ipv4/fib_semantics.c

@@ -208,7 +208,7 @@ static void rt_fibinfo_free_cpus(struct rtable __rcu * __percpu *rtp)
 
 void fib_nh_common_release(struct fib_nh_common *nhc)
 {
-	dev_put(nhc->nhc_dev);
+	dev_put_track(nhc->nhc_dev, &nhc->nhc_dev_tracker);
 	lwtstate_put(nhc->nhc_lwtstate);
 	rt_fibinfo_free_cpus(nhc->nhc_pcpu_rth_output);
 	rt_fibinfo_free(&nhc->nhc_rth_input);
@@ -1006,7 +1006,7 @@ static int fib_check_nh_v6_gw(struct net *net, struct fib_nh *nh,
 	err = ipv6_stub->fib6_nh_init(net, &fib6_nh, &cfg, GFP_KERNEL, extack);
 	if (!err) {
 		nh->fib_nh_dev = fib6_nh.fib_nh_dev;
-		dev_hold(nh->fib_nh_dev);
+		dev_hold_track(nh->fib_nh_dev, &nh->fib_nh_dev_tracker, GFP_KERNEL);
 		nh->fib_nh_oif = nh->fib_nh_dev->ifindex;
 		nh->fib_nh_scope = RT_SCOPE_LINK;
 
@@ -1090,7 +1090,7 @@ static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table,
 		if (!netif_carrier_ok(dev))
 			nh->fib_nh_flags |= RTNH_F_LINKDOWN;
 		nh->fib_nh_dev = dev;
-		dev_hold(dev);
+		dev_hold_track(dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC);
 		nh->fib_nh_scope = RT_SCOPE_LINK;
 		return 0;
 	}
@@ -1144,7 +1144,7 @@ static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table,
 			       "No egress device for nexthop gateway");
 		goto out;
 	}
-	dev_hold(dev);
+	dev_hold_track(dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC);
 	if (!netif_carrier_ok(dev))
 		nh->fib_nh_flags |= RTNH_F_LINKDOWN;
 	err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN;
@@ -1178,7 +1178,7 @@ static int fib_check_nh_nongw(struct net *net, struct fib_nh *nh,
 	}
 
 	nh->fib_nh_dev = in_dev->dev;
-	dev_hold(nh->fib_nh_dev);
+	dev_hold_track(nh->fib_nh_dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC);
 	nh->fib_nh_scope = RT_SCOPE_HOST;
 	if (!netif_carrier_ok(nh->fib_nh_dev))
 		nh->fib_nh_flags |= RTNH_F_LINKDOWN;
@@ -1508,6 +1508,8 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 		err = -ENODEV;
 		if (!nh->fib_nh_dev)
 			goto failure;
+		netdev_tracker_alloc(nh->fib_nh_dev, &nh->fib_nh_dev_tracker,
+				     GFP_KERNEL);
 	} else {
 		int linkdown = 0;
 

net/ipv6/route.c

@@ -3628,6 +3628,8 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
 	}
 
 	fib6_nh->fib_nh_dev = dev;
+	netdev_tracker_alloc(dev, &fib6_nh->fib_nh_dev_tracker, gfp_flags);
+
 	fib6_nh->fib_nh_oif = dev->ifindex;
 	err = 0;
 out: