1 files changed, 14 insertions, 7 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 2897403fdaff..0e381bb94683 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -77,7 +77,7 @@ static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort,
                                     const struct in6_addr *dest);
 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie);
 static unsigned int      ip6_default_advmss(const struct dst_entry *dst);
-static unsigned int      ip6_default_mtu(const struct dst_entry *dst);
+static unsigned int      ip6_mtu(const struct dst_entry *dst);
 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
 static void             ip6_dst_destroy(struct dst_entry *);
 static void             ip6_dst_ifdown(struct dst_entry *,
@@ -144,7 +144,7 @@ static struct dst_ops ip6_dst_ops_template = {
         .gc_thresh              =       1024,
         .check                  =       ip6_dst_check,
         .default_advmss         =       ip6_default_advmss,
-        .default_mtu            =       ip6_default_mtu,
+        .mtu                    =       ip6_mtu,
         .cow_metrics            =       ipv6_cow_metrics,
         .destroy                =       ip6_dst_destroy,
         .ifdown                 =       ip6_dst_ifdown,
@@ -155,9 +155,11 @@ static struct dst_ops ip6_dst_ops_template = {
         .neigh_lookup           =       ip6_neigh_lookup,
 };
 
-static unsigned int ip6_blackhole_default_mtu(const struct dst_entry *dst)
+static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst)
 {
-        return 0;
+        unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
+
+        return mtu ? : dst->dev->mtu;
 }
 
 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
@@ -175,7 +177,7 @@ static struct dst_ops ip6_dst_blackhole_ops = {
         .protocol               =       cpu_to_be16(ETH_P_IPV6),
         .destroy                =       ip6_dst_destroy,
         .check                  =       ip6_dst_check,
-        .default_mtu            =       ip6_blackhole_default_mtu,
+        .mtu                    =       ip6_blackhole_mtu,
         .default_advmss         =       ip6_default_advmss,
         .update_pmtu            =       ip6_rt_blackhole_update_pmtu,
         .cow_metrics            =       ip6_rt_blackhole_cow_metrics,
@@ -1041,10 +1043,15 @@ static unsigned int ip6_default_advmss(const struct dst_entry *dst)
         return mtu;
 }
 
-static unsigned int ip6_default_mtu(const struct dst_entry *dst)
+static unsigned int ip6_mtu(const struct dst_entry *dst)
 {
-        unsigned int mtu = IPV6_MIN_MTU;
         struct inet6_dev *idev;
+        unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
+
+        if (mtu)
+                return mtu;
+
+        mtu = IPV6_MIN_MTU;
 
         rcu_read_lock();
         idev = __in6_dev_get(dst->dev);