1 files changed, 32 insertions, 15 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index e74ee837b300..4ac5728689f5 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -635,6 +635,7 @@ static inline u32 fnhe_hashfun(__be32 daddr)
 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
 {
 	rt->rt_pmtu = fnhe->fnhe_pmtu;
+	rt->rt_mtu_locked = fnhe->fnhe_mtu_locked;
 	rt->dst.expires = fnhe->fnhe_expires;
 
 	if (fnhe->fnhe_gw) {
@@ -645,7 +646,7 @@ static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnh
 }
 
 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
-				  u32 pmtu, unsigned long expires)
+				  u32 pmtu, bool lock, unsigned long expires)
 {
 	struct fnhe_hash_bucket *hash;
 	struct fib_nh_exception *fnhe;
@@ -682,8 +683,10 @@ static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
 			fnhe->fnhe_genid = genid;
 		if (gw)
 			fnhe->fnhe_gw = gw;
-		if (pmtu)
+		if (pmtu) {
 			fnhe->fnhe_pmtu = pmtu;
+			fnhe->fnhe_mtu_locked = lock;
+		}
 		fnhe->fnhe_expires = max(1UL, expires);
 		/* Update all cached dsts too */
 		rt = rcu_dereference(fnhe->fnhe_rth_input);
@@ -707,6 +710,7 @@ static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
 		fnhe->fnhe_daddr = daddr;
 		fnhe->fnhe_gw = gw;
 		fnhe->fnhe_pmtu = pmtu;
+		fnhe->fnhe_mtu_locked = lock;
 		fnhe->fnhe_expires = expires;
 
 		/* Exception created; mark the cached routes for the nexthop
@@ -788,7 +792,8 @@ static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flow
 				struct fib_nh *nh = &FIB_RES_NH(res);
 
 				update_or_create_fnhe(nh, fl4->daddr, new_gw,
-						0, jiffies + ip_rt_gc_timeout);
+						0, false,
+						jiffies + ip_rt_gc_timeout);
 			}
 			if (kill_route)
 				rt->dst.obsolete = DST_OBSOLETE_KILL;
@@ -1010,15 +1015,18 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
 {
 	struct dst_entry *dst = &rt->dst;
 	struct fib_result res;
+	bool lock = false;
 
-	if (dst_metric_locked(dst, RTAX_MTU))
+	if (ip_mtu_locked(dst))
 		return;
 
 	if (ipv4_mtu(dst) < mtu)
 		return;
 
-	if (mtu < ip_rt_min_pmtu)
+	if (mtu < ip_rt_min_pmtu) {
+		lock = true;
 		mtu = ip_rt_min_pmtu;
+	}
 
 	if (rt->rt_pmtu == mtu &&
 	    time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
@@ -1028,7 +1036,7 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
 	if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
 		struct fib_nh *nh = &FIB_RES_NH(res);
 
-		update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
+		update_or_create_fnhe(nh, fl4->daddr, 0, mtu, lock,
 				      jiffies + ip_rt_mtu_expires);
 	}
 	rcu_read_unlock();
@@ -1281,7 +1289,7 @@ static unsigned int ipv4_mtu(const struct dst_entry *dst)
 
 	mtu = READ_ONCE(dst->dev->mtu);
 
-	if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
+	if (unlikely(ip_mtu_locked(dst))) {
 		if (rt->rt_uses_gateway && mtu > 576)
 			mtu = 576;
 	}
@@ -1394,7 +1402,7 @@ struct uncached_list {
 
 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
 
-static void rt_add_uncached_list(struct rtable *rt)
+void rt_add_uncached_list(struct rtable *rt)
 {
 	struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
 
@@ -1405,14 +1413,8 @@ static void rt_add_uncached_list(struct rtable *rt)
 	spin_unlock_bh(&ul->lock);
 }
 
-static void ipv4_dst_destroy(struct dst_entry *dst)
+void rt_del_uncached_list(struct rtable *rt)
 {
-	struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
-	struct rtable *rt = (struct rtable *) dst;
-
-	if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
-		kfree(p);
-
 	if (!list_empty(&rt->rt_uncached)) {
 		struct uncached_list *ul = rt->rt_uncached_list;
 
@@ -1422,6 +1424,17 @@ static void ipv4_dst_destroy(struct dst_entry *dst)
 	}
 }
 
+static void ipv4_dst_destroy(struct dst_entry *dst)
+{
+	struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
+	struct rtable *rt = (struct rtable *)dst;
+
+	if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
+		kfree(p);
+
+	rt_del_uncached_list(rt);
+}
+
 void rt_flush_dev(struct net_device *dev)
 {
 	struct net *net = dev_net(dev);
@@ -1517,6 +1530,7 @@ struct rtable *rt_dst_alloc(struct net_device *dev,
 		rt->rt_is_input = 0;
 		rt->rt_iif = 0;
 		rt->rt_pmtu = 0;
+		rt->rt_mtu_locked = 0;
 		rt->rt_gateway = 0;
 		rt->rt_uses_gateway = 0;
 		INIT_LIST_HEAD(&rt->rt_uncached);
@@ -2533,6 +2547,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
 		rt->rt_is_input = ort->rt_is_input;
 		rt->rt_iif = ort->rt_iif;
 		rt->rt_pmtu = ort->rt_pmtu;
+		rt->rt_mtu_locked = ort->rt_mtu_locked;
 
 		rt->rt_genid = rt_genid_ipv4(net);
 		rt->rt_flags = ort->rt_flags;
@@ -2635,6 +2650,8 @@ static int rt_fill_info(struct net *net,  __be32 dst, __be32 src, u32 table_id,
 	memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
 	if (rt->rt_pmtu && expires)
 		metrics[RTAX_MTU - 1] = rt->rt_pmtu;
+	if (rt->rt_mtu_locked && expires)
+		metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
 	if (rtnetlink_put_metrics(skb, metrics) < 0)
 		goto nla_put_failure;