ipv4: make sure nh_pcpu_rth_output is always allocated

Avoid checking nh_pcpu_rth_output in fast path,
abort fib_info creation on alloc_percpu failure.
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/fib_semantics.c

@@ -840,6 +840,8 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
 	change_nexthops(fi) {
 		nexthop_nh->nh_parent = fi;
 		nexthop_nh->nh_pcpu_rth_output = alloc_percpu(struct rtable __rcu *);
+		if (!nexthop_nh->nh_pcpu_rth_output)
+			goto failure;
 	} endfor_nexthops(fi)
 
 	if (cfg->fc_mx) {

net/ipv4/route.c

@@ -1207,8 +1207,6 @@ static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
 	if (rt_is_input_route(rt)) {
 		p = (struct rtable **)&nh->nh_rth_input;
 	} else {
-		if (!nh->nh_pcpu_rth_output)
-			goto nocache;
 		p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
 	}
 	orig = *p;
@@ -1223,7 +1221,6 @@ static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
 		 * unsuccessful at storing this route into the cache
 		 * we really need to set it.
 		 */
-nocache:
 		rt->dst.flags |= DST_NOCACHE;
 		ret = false;
 	}