net: Abstract away all dst_entry metrics accesses.

Use helper functions to hide all direct accesses, especially writes,
to dst_entry metrics values.

This will allow us to:

1) More easily change how the metrics are stored.

2) Implement COW for metrics.

In particular this will help us put metrics into the inetpeer
cache if that is what we end up doing.  We can make the _metrics
member a pointer instead of an array, initially have it point
at the read-only metrics in the FIB, and then on the first set
grab an inetpeer entry and point the _metrics member there.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 17cb0b6..5564435 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -141,7 +141,7 @@
 
 #ifdef CONFIG_BRIDGE_NETFILTER
 	/* remember the MTU in the rtable for PMTU */
-	br->fake_rtable.dst.metrics[RTAX_MTU - 1] = new_mtu;
+	dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 #endif
 
 	return 0;
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 6e13920..16f5c33 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -124,7 +124,7 @@
 	atomic_set(&rt->dst.__refcnt, 1);
 	rt->dst.dev = br->dev;
 	rt->dst.path = &rt->dst;
-	rt->dst.metrics[RTAX_MTU - 1] = 1500;
+	dst_metric_set(&rt->dst, RTAX_MTU, 1500);
 	rt->dst.flags	= DST_NOXFRM;
 	rt->dst.ops = &fake_dst_ops;
 }
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 8280e43..e2e9268 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -240,13 +240,13 @@
 
 	if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
 		if (!(dst_metric_locked(dst, RTAX_MTU))) {
-			dst->metrics[RTAX_MTU-1] = mtu;
+			dst_metric_set(dst, RTAX_MTU, mtu);
 			dst_set_expires(dst, dn_rt_mtu_expires);
 		}
 		if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
 			u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
 			if (dst_metric(dst, RTAX_ADVMSS) > mss)
-				dst->metrics[RTAX_ADVMSS-1] = mss;
+				dst_metric_set(dst, RTAX_ADVMSS, mss);
 		}
 	}
 }
@@ -806,8 +806,7 @@
 		if (DN_FIB_RES_GW(*res) &&
 		    DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 			rt->rt_gateway = DN_FIB_RES_GW(*res);
-		memcpy(rt->dst.metrics, fi->fib_metrics,
-		       sizeof(rt->dst.metrics));
+		dst_import_metrics(&rt->dst, fi->fib_metrics);
 	}
 	rt->rt_type = res->type;
 
@@ -820,11 +819,11 @@
 
 	if (dst_metric(&rt->dst, RTAX_MTU) == 0 ||
 	    dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
-		rt->dst.metrics[RTAX_MTU-1] = rt->dst.dev->mtu;
+		dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
 	mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
 	if (dst_metric(&rt->dst, RTAX_ADVMSS) == 0 ||
 	    dst_metric(&rt->dst, RTAX_ADVMSS) > mss)
-		rt->dst.metrics[RTAX_ADVMSS-1] = mss;
+		dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
 	return 0;
 }
 
@@ -1502,7 +1501,7 @@
 	RTA_PUT(skb, RTA_PREFSRC, 2, &rt->rt_local_src);
 	if (rt->rt_daddr != rt->rt_gateway)
 		RTA_PUT(skb, RTA_GATEWAY, 2, &rt->rt_gateway);
-	if (rtnetlink_put_metrics(skb, rt->dst.metrics) < 0)
+	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
 		goto rtattr_failure;
 	expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
 	if (rtnl_put_cacheinfo(skb, &rt->dst, 0, 0, 0, expires,
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 258c98d..ff4e7a4 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -818,7 +818,7 @@
 			     !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
 			    rt6->rt6i_dst.plen == 128) {
 				rt6->rt6i_flags |= RTF_MODIFIED;
-				skb_dst(skb)->metrics[RTAX_MTU-1] = mtu;
+				dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
 			}
 		}
 
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 3843c2d..26ac396 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1686,11 +1686,14 @@
 					if (mtu < dst_mtu(&rth->dst)) {
 						dst_confirm(&rth->dst);
 						if (mtu < ip_rt_min_pmtu) {
+							u32 lock = dst_metric(&rth->dst,
+									      RTAX_LOCK);
 							mtu = ip_rt_min_pmtu;
-							rth->dst.metrics[RTAX_LOCK-1] |=
-								(1 << RTAX_MTU);
+							lock |= (1 << RTAX_MTU);
+							dst_metric_set(&rth->dst, RTAX_LOCK,
+								       lock);
 						}
-						rth->dst.metrics[RTAX_MTU-1] = mtu;
+						dst_metric_set(&rth->dst, RTAX_MTU, mtu);
 						dst_set_expires(&rth->dst,
 							ip_rt_mtu_expires);
 					}
@@ -1708,10 +1711,11 @@
 	if (dst_mtu(dst) > mtu && mtu >= 68 &&
 	    !(dst_metric_locked(dst, RTAX_MTU))) {
 		if (mtu < ip_rt_min_pmtu) {
+			u32 lock = dst_metric(dst, RTAX_LOCK);
 			mtu = ip_rt_min_pmtu;
-			dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
+			dst_metric_set(dst, RTAX_LOCK, lock | (1 << RTAX_MTU));
 		}
-		dst->metrics[RTAX_MTU-1] = mtu;
+		dst_metric_set(dst, RTAX_MTU, mtu);
 		dst_set_expires(dst, ip_rt_mtu_expires);
 		call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
 	}
@@ -1796,36 +1800,37 @@
 
 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
 {
+	struct dst_entry *dst = &rt->dst;
 	struct fib_info *fi = res->fi;
 
 	if (fi) {
 		if (FIB_RES_GW(*res) &&
 		    FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 			rt->rt_gateway = FIB_RES_GW(*res);
-		memcpy(rt->dst.metrics, fi->fib_metrics,
-		       sizeof(rt->dst.metrics));
+		dst_import_metrics(dst, fi->fib_metrics);
 		if (fi->fib_mtu == 0) {
-			rt->dst.metrics[RTAX_MTU-1] = rt->dst.dev->mtu;
-			if (dst_metric_locked(&rt->dst, RTAX_MTU) &&
+			dst_metric_set(dst, RTAX_MTU, dst->dev->mtu);
+			if (dst_metric_locked(dst, RTAX_MTU) &&
 			    rt->rt_gateway != rt->rt_dst &&
-			    rt->dst.dev->mtu > 576)
-				rt->dst.metrics[RTAX_MTU-1] = 576;
+			    dst->dev->mtu > 576)
+				dst_metric_set(dst, RTAX_MTU, 576);
 		}
 #ifdef CONFIG_NET_CLS_ROUTE
-		rt->dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
+		dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
 #endif
 	} else
-		rt->dst.metrics[RTAX_MTU-1]= rt->dst.dev->mtu;
+		dst_metric_set(dst, RTAX_MTU, dst->dev->mtu);
 
-	if (dst_metric(&rt->dst, RTAX_HOPLIMIT) == 0)
-		rt->dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
-	if (dst_mtu(&rt->dst) > IP_MAX_MTU)
-		rt->dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
-	if (dst_metric(&rt->dst, RTAX_ADVMSS) == 0)
-		rt->dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->dst.dev->mtu - 40,
-				       ip_rt_min_advmss);
-	if (dst_metric(&rt->dst, RTAX_ADVMSS) > 65535 - 40)
-		rt->dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
+	if (dst_metric(dst, RTAX_HOPLIMIT) == 0)
+		dst_metric_set(dst, RTAX_HOPLIMIT, sysctl_ip_default_ttl);
+	if (dst_mtu(dst) > IP_MAX_MTU)
+		dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
+	if (dst_metric(dst, RTAX_ADVMSS) == 0)
+		dst_metric_set(dst, RTAX_ADVMSS,
+			       max_t(unsigned int, dst->dev->mtu - 40,
+				     ip_rt_min_advmss));
+	if (dst_metric(dst, RTAX_ADVMSS) > 65535 - 40)
+		dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
 
 #ifdef CONFIG_NET_CLS_ROUTE
 #ifdef CONFIG_IP_MULTIPLE_TABLES
@@ -2720,7 +2725,7 @@
 		new->__use = 1;
 		new->input = dst_discard;
 		new->output = dst_discard;
-		memcpy(new->metrics, ort->dst.metrics, RTAX_MAX*sizeof(u32));
+		dst_copy_metrics(new, &ort->dst);
 
 		new->dev = ort->dst.dev;
 		if (new->dev)
@@ -2827,7 +2832,7 @@
 	if (rt->rt_dst != rt->rt_gateway)
 		NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
 
-	if (rtnetlink_put_metrics(skb, rt->dst.metrics) < 0)
+	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
 		goto nla_put_failure;
 
 	if (rt->fl.mark)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 6d8ab1c..824e8c8 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -734,7 +734,7 @@
 			 * Reset our results.
 			 */
 			if (!(dst_metric_locked(dst, RTAX_RTT)))
-				dst->metrics[RTAX_RTT - 1] = 0;
+				dst_metric_set(dst, RTAX_RTT, 0);
 			return;
 		}
 
@@ -776,34 +776,38 @@
 			if (dst_metric(dst, RTAX_SSTHRESH) &&
 			    !dst_metric_locked(dst, RTAX_SSTHRESH) &&
 			    (tp->snd_cwnd >> 1) > dst_metric(dst, RTAX_SSTHRESH))
-				dst->metrics[RTAX_SSTHRESH-1] = tp->snd_cwnd >> 1;
+				dst_metric_set(dst, RTAX_SSTHRESH, tp->snd_cwnd >> 1);
 			if (!dst_metric_locked(dst, RTAX_CWND) &&
 			    tp->snd_cwnd > dst_metric(dst, RTAX_CWND))
-				dst->metrics[RTAX_CWND - 1] = tp->snd_cwnd;
+				dst_metric_set(dst, RTAX_CWND, tp->snd_cwnd);
 		} else if (tp->snd_cwnd > tp->snd_ssthresh &&
 			   icsk->icsk_ca_state == TCP_CA_Open) {
 			/* Cong. avoidance phase, cwnd is reliable. */
 			if (!dst_metric_locked(dst, RTAX_SSTHRESH))
-				dst->metrics[RTAX_SSTHRESH-1] =
-					max(tp->snd_cwnd >> 1, tp->snd_ssthresh);
+				dst_metric_set(dst, RTAX_SSTHRESH,
+					       max(tp->snd_cwnd >> 1, tp->snd_ssthresh));
 			if (!dst_metric_locked(dst, RTAX_CWND))
-				dst->metrics[RTAX_CWND-1] = (dst_metric(dst, RTAX_CWND) + tp->snd_cwnd) >> 1;
+				dst_metric_set(dst, RTAX_CWND,
+					       (dst_metric(dst, RTAX_CWND) +
+						tp->snd_cwnd) >> 1);
 		} else {
 			/* Else slow start did not finish, cwnd is non-sense,
 			   ssthresh may be also invalid.
 			 */
 			if (!dst_metric_locked(dst, RTAX_CWND))
-				dst->metrics[RTAX_CWND-1] = (dst_metric(dst, RTAX_CWND) + tp->snd_ssthresh) >> 1;
+				dst_metric_set(dst, RTAX_CWND,
+					       (dst_metric(dst, RTAX_CWND) +
+						tp->snd_ssthresh) >> 1);
 			if (dst_metric(dst, RTAX_SSTHRESH) &&
 			    !dst_metric_locked(dst, RTAX_SSTHRESH) &&
 			    tp->snd_ssthresh > dst_metric(dst, RTAX_SSTHRESH))
-				dst->metrics[RTAX_SSTHRESH-1] = tp->snd_ssthresh;
+				dst_metric_set(dst, RTAX_SSTHRESH, tp->snd_ssthresh);
 		}
 
 		if (!dst_metric_locked(dst, RTAX_REORDERING)) {
 			if (dst_metric(dst, RTAX_REORDERING) < tp->reordering &&
 			    tp->reordering != sysctl_tcp_reordering)
-				dst->metrics[RTAX_REORDERING-1] = tp->reordering;
+				dst_metric_set(dst, RTAX_REORDERING, tp->reordering);
 		}
 	}
 }
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index e18f841..2342545 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1259,7 +1259,8 @@
 	if (ra_msg->icmph.icmp6_hop_limit) {
 		in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
 		if (rt)
-			rt->dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit;
+			dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
+				       ra_msg->icmph.icmp6_hop_limit);
 	}
 
 skip_defrtr:
@@ -1377,7 +1378,7 @@
 			in6_dev->cnf.mtu6 = mtu;
 
 			if (rt)
-				rt->dst.metrics[RTAX_MTU-1] = mtu;
+				dst_metric_set(&rt->dst, RTAX_MTU, mtu);
 
 			rt6_mtu_change(skb->dev, mtu);
 		}
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 026caef..4aed081 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -129,7 +129,6 @@
 		.__use		= 1,
 		.obsolete	= -1,
 		.error		= -ENETUNREACH,
-		.metrics	= { [RTAX_HOPLIMIT - 1] = 255, },
 		.input		= ip6_pkt_discard,
 		.output		= ip6_pkt_discard_out,
 	},
@@ -150,7 +149,6 @@
 		.__use		= 1,
 		.obsolete	= -1,
 		.error		= -EACCES,
-		.metrics	= { [RTAX_HOPLIMIT - 1] = 255, },
 		.input		= ip6_pkt_prohibit,
 		.output		= ip6_pkt_prohibit_out,
 	},
@@ -166,7 +164,6 @@
 		.__use		= 1,
 		.obsolete	= -1,
 		.error		= -EINVAL,
-		.metrics	= { [RTAX_HOPLIMIT - 1] = 255, },
 		.input		= dst_discard,
 		.output		= dst_discard,
 	},
@@ -844,7 +841,7 @@
 		new->input = dst_discard;
 		new->output = dst_discard;
 
-		memcpy(new->metrics, ort->dst.metrics, RTAX_MAX*sizeof(u32));
+		dst_copy_metrics(new, &ort->dst);
 		new->dev = ort->dst.dev;
 		if (new->dev)
 			dev_hold(new->dev);
@@ -928,10 +925,12 @@
 	if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) {
 		rt6->rt6i_flags |= RTF_MODIFIED;
 		if (mtu < IPV6_MIN_MTU) {
+			u32 features = dst_metric(dst, RTAX_FEATURES);
 			mtu = IPV6_MIN_MTU;
-			dst->metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
+			features |= RTAX_FEATURE_ALLFRAG;
+			dst_metric_set(dst, RTAX_FEATURES, features);
 		}
-		dst->metrics[RTAX_MTU-1] = mtu;
+		dst_metric_set(dst, RTAX_MTU, mtu);
 		call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
 	}
 }
@@ -989,9 +988,9 @@
 	rt->rt6i_idev     = idev;
 	rt->rt6i_nexthop  = neigh;
 	atomic_set(&rt->dst.__refcnt, 1);
-	rt->dst.metrics[RTAX_HOPLIMIT-1] = 255;
-	rt->dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev);
-	rt->dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(net, dst_mtu(&rt->dst));
+	dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 255);
+	dst_metric_set(&rt->dst, RTAX_MTU, ipv6_get_mtu(rt->rt6i_dev));
+	dst_metric_set(&rt->dst, RTAX_ADVMSS, ipv6_advmss(net, dst_mtu(&rt->dst)));
 	rt->dst.output  = ip6_output;
 
 #if 0	/* there's no chance to use these for ndisc */
@@ -1305,17 +1304,17 @@
 					goto out;
 				}
 
-				rt->dst.metrics[type - 1] = nla_get_u32(nla);
+				dst_metric_set(&rt->dst, type, nla_get_u32(nla));
 			}
 		}
 	}
 
 	if (dst_metric(&rt->dst, RTAX_HOPLIMIT) == 0)
-		rt->dst.metrics[RTAX_HOPLIMIT-1] = -1;
+		dst_metric_set(&rt->dst, RTAX_HOPLIMIT, -1);
 	if (!dst_mtu(&rt->dst))
-		rt->dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(dev);
+		dst_metric_set(&rt->dst, RTAX_MTU, ipv6_get_mtu(dev));
 	if (!dst_metric(&rt->dst, RTAX_ADVMSS))
-		rt->dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(net, dst_mtu(&rt->dst));
+		dst_metric_set(&rt->dst, RTAX_ADVMSS, ipv6_advmss(net, dst_mtu(&rt->dst)));
 	rt->dst.dev = dev;
 	rt->rt6i_idev = idev;
 	rt->rt6i_table = table;
@@ -1541,9 +1540,9 @@
 	ipv6_addr_copy(&nrt->rt6i_gateway, (struct in6_addr*)neigh->primary_key);
 	nrt->rt6i_nexthop = neigh_clone(neigh);
 	/* Reset pmtu, it may be better */
-	nrt->dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(neigh->dev);
-	nrt->dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dev_net(neigh->dev),
-							dst_mtu(&nrt->dst));
+	dst_metric_set(&nrt->dst, RTAX_MTU, ipv6_get_mtu(neigh->dev));
+	dst_metric_set(&nrt->dst, RTAX_ADVMSS, ipv6_advmss(dev_net(neigh->dev),
+							   dst_mtu(&nrt->dst)));
 
 	if (ip6_ins_rt(nrt))
 		goto out;
@@ -1602,9 +1601,12 @@
 	   would return automatically.
 	 */
 	if (rt->rt6i_flags & RTF_CACHE) {
-		rt->dst.metrics[RTAX_MTU-1] = pmtu;
-		if (allfrag)
-			rt->dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
+		dst_metric_set(&rt->dst, RTAX_MTU, pmtu);
+		if (allfrag) {
+			u32 features = dst_metric(&rt->dst, RTAX_FEATURES);
+			features |= RTAX_FEATURE_ALLFRAG;
+			dst_metric_set(&rt->dst, RTAX_FEATURES, features);
+		}
 		dst_set_expires(&rt->dst, net->ipv6.sysctl.ip6_rt_mtu_expires);
 		rt->rt6i_flags |= RTF_MODIFIED|RTF_EXPIRES;
 		goto out;
@@ -1621,9 +1623,12 @@
 		nrt = rt6_alloc_clone(rt, daddr);
 
 	if (nrt) {
-		nrt->dst.metrics[RTAX_MTU-1] = pmtu;
-		if (allfrag)
-			nrt->dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
+		dst_metric_set(&nrt->dst, RTAX_MTU, pmtu);
+		if (allfrag) {
+			u32 features = dst_metric(&nrt->dst, RTAX_FEATURES);
+			features |= RTAX_FEATURE_ALLFRAG;
+			dst_metric_set(&nrt->dst, RTAX_FEATURES, features);
+		}
 
 		/* According to RFC 1981, detecting PMTU increase shouldn't be
 		 * happened within 5 mins, the recommended timer is 10 mins.
@@ -1674,7 +1679,7 @@
 		rt->dst.input = ort->dst.input;
 		rt->dst.output = ort->dst.output;
 
-		memcpy(rt->dst.metrics, ort->dst.metrics, RTAX_MAX*sizeof(u32));
+		dst_copy_metrics(&rt->dst, &ort->dst);
 		rt->dst.error = ort->dst.error;
 		rt->dst.dev = ort->dst.dev;
 		if (rt->dst.dev)
@@ -1966,9 +1971,9 @@
 	rt->dst.output = ip6_output;
 	rt->rt6i_dev = net->loopback_dev;
 	rt->rt6i_idev = idev;
-	rt->dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev);
-	rt->dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(net, dst_mtu(&rt->dst));
-	rt->dst.metrics[RTAX_HOPLIMIT-1] = -1;
+	dst_metric_set(&rt->dst, RTAX_MTU, ipv6_get_mtu(rt->rt6i_dev));
+	dst_metric_set(&rt->dst, RTAX_ADVMSS, ipv6_advmss(net, dst_mtu(&rt->dst)));
+	dst_metric_set(&rt->dst, RTAX_HOPLIMIT, -1);
 	rt->dst.obsolete = -1;
 
 	rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP;
@@ -2068,8 +2073,8 @@
 	    (dst_mtu(&rt->dst) >= arg->mtu ||
 	     (dst_mtu(&rt->dst) < arg->mtu &&
 	      dst_mtu(&rt->dst) == idev->cnf.mtu6))) {
-		rt->dst.metrics[RTAX_MTU-1] = arg->mtu;
-		rt->dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(net, arg->mtu);
+		dst_metric_set(&rt->dst, RTAX_MTU, arg->mtu);
+		dst_metric_set(&rt->dst, RTAX_ADVMSS, ipv6_advmss(net, arg->mtu));
 	}
 	return 0;
 }
@@ -2295,7 +2300,7 @@
 			NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);
 	}
 
-	if (rtnetlink_put_metrics(skb, rt->dst.metrics) < 0)
+	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
 		goto nla_put_failure;
 
 	if (rt->dst.neighbour)
@@ -2686,6 +2691,7 @@
 	net->ipv6.ip6_null_entry->dst.path =
 		(struct dst_entry *)net->ipv6.ip6_null_entry;
 	net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
+	dst_metric_set(&net->ipv6.ip6_null_entry->dst, RTAX_HOPLIMIT, 255);
 
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 	net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
@@ -2696,6 +2702,7 @@
 	net->ipv6.ip6_prohibit_entry->dst.path =
 		(struct dst_entry *)net->ipv6.ip6_prohibit_entry;
 	net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
+	dst_metric_set(&net->ipv6.ip6_prohibit_entry->dst, RTAX_HOPLIMIT, 255);
 
 	net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
 					       sizeof(*net->ipv6.ip6_blk_hole_entry),
@@ -2705,6 +2712,7 @@
 	net->ipv6.ip6_blk_hole_entry->dst.path =
 		(struct dst_entry *)net->ipv6.ip6_blk_hole_entry;
 	net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
+	dst_metric_set(&net->ipv6.ip6_blk_hole_entry->dst, RTAX_HOPLIMIT, 255);
 #endif
 
 	net->ipv6.sysctl.flush_delay = 0;
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 044e778..6e50ccd 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1433,7 +1433,7 @@
 		}
 
 		xdst->route = dst;
-		memcpy(&dst1->metrics, &dst->metrics, sizeof(dst->metrics));
+		dst_copy_metrics(dst1, dst);
 
 		if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
 			family = xfrm[i]->props.family;
@@ -2271,7 +2271,7 @@
 		if (pmtu > route_mtu_cached)
 			pmtu = route_mtu_cached;
 
-		dst->metrics[RTAX_MTU-1] = pmtu;
+		dst_metric_set(dst, RTAX_MTU, pmtu);
 	} while ((dst = dst->next));
 }
 
@@ -2349,7 +2349,7 @@
 		mtu = xfrm_state_mtu(dst->xfrm, mtu);
 		if (mtu > last->route_mtu_cached)
 			mtu = last->route_mtu_cached;
-		dst->metrics[RTAX_MTU-1] = mtu;
+		dst_metric_set(dst, RTAX_MTU, mtu);
 
 		if (last == first)
 			break;