ipv4: Don't miss existing cached metrics in new routes.

Always lookup to see if we have an existing inetpeer entry for
a route.  Let FLOWI_FLAG_PRECOW_METRICS merely influence the
"create" argument to rt_bind_peer().

Also, call rt_bind_peer() unconditionally since it is not
possible for rt->peer to be non-NULL at this point.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/route.c

@@ -1859,25 +1859,28 @@ static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
 
 static void rt_init_metrics(struct rtable *rt, struct fib_info *fi)
 {
-	if (!(rt->fl.flags & FLOWI_FLAG_PRECOW_METRICS)) {
-	no_cow:
-		if (fi->fib_metrics != (u32 *) dst_default_metrics) {
-			rt->fi = fi;
-			atomic_inc(&fi->fib_clntref);
-		}
-		dst_init_metrics(&rt->dst, fi->fib_metrics, true);
-	} else {
-		struct inet_peer *peer;
+	struct inet_peer *peer;
+	int create = 0;
 
-		if (!rt->peer)
-			rt_bind_peer(rt, 1);
-		peer = rt->peer;
-		if (!peer)
-			goto no_cow;
+	/* If a peer entry exists for this destination, we must hook
+	 * it up in order to get at cached metrics.
+	 */
+	if (rt->fl.flags & FLOWI_FLAG_PRECOW_METRICS)
+		create = 1;
+
+	rt_bind_peer(rt, create);
+	peer = rt->peer;
+	if (peer) {
 		if (inet_metrics_new(peer))
 			memcpy(peer->metrics, fi->fib_metrics,
 			       sizeof(u32) * RTAX_MAX);
 		dst_init_metrics(&rt->dst, peer->metrics, false);
+	} else {
+		if (fi->fib_metrics != (u32 *) dst_default_metrics) {
+			rt->fi = fi;
+			atomic_inc(&fi->fib_clntref);
+		}
+		dst_init_metrics(&rt->dst, fi->fib_metrics, true);
 	}
 }