net: common metrics init helper for dst_entry

ipv4 and ipv6 both use refcounted metrics if FIB entries have metrics set.
Move the common initialization code to a helper and use for both protocols.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip.h

@@ -429,6 +429,18 @@ static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics)
 		kfree(fib_metrics);
 }
 
+/* ipv4 and ipv6 both use refcounted metrics if it is not the default */
+static inline
+void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics)
+{
+	dst_init_metrics(dst, fib_metrics->metrics, true);
+
+	if (fib_metrics != &dst_default_metrics) {
+		dst->_metrics |= DST_METRICS_REFCOUNTED;
+		refcount_inc(&fib_metrics->refcnt);
+	}
+}
+
 u32 ip_idents_reserve(u32 hash, int segs);
 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
 

net/ipv4/route.c

@@ -1528,11 +1528,8 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
 			rt->rt_gateway = nh->nh_gw;
 			rt->rt_uses_gateway = 1;
 		}
-		dst_init_metrics(&rt->dst, fi->fib_metrics->metrics, true);
-		if (fi->fib_metrics != &dst_default_metrics) {
-			rt->dst._metrics |= DST_METRICS_REFCOUNTED;
-			refcount_inc(&fi->fib_metrics->refcnt);
-		}
+		ip_dst_init_metrics(&rt->dst, fi->fib_metrics);
+
 #ifdef CONFIG_IP_ROUTE_CLASSID
 		rt->dst.tclassid = nh->nh_tclassid;
 #endif

net/ipv6/route.c

@@ -978,11 +978,7 @@ static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
 {
 	rt->rt6i_flags &= ~RTF_EXPIRES;
 	rcu_assign_pointer(rt->from, from);
-	dst_init_metrics(&rt->dst, from->fib6_metrics->metrics, true);
-	if (from->fib6_metrics != &dst_default_metrics) {
-		rt->dst._metrics |= DST_METRICS_REFCOUNTED;
-		refcount_inc(&from->fib6_metrics->refcnt);
-	}
+	ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
 }
 
 /* Caller must already hold reference to @ort */