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;