ipv6: Handle all fib6_nh in a nexthop in fib6_drop_pcpu_from

Use nexthop_for_each_fib6_nh to walk all fib6_nh in a nexthop when
dropping 'from' reference in pcpu routes.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ip6_fib.c

@@ -906,19 +906,42 @@ static void __fib6_drop_pcpu_from(struct fib6_nh *fib6_nh,
 	}
 }
 
+struct fib6_nh_pcpu_arg {
+	struct fib6_info	*from;
+	const struct fib6_table *table;
+};
+
+static int fib6_nh_drop_pcpu_from(struct fib6_nh *nh, void *_arg)
+{
+	struct fib6_nh_pcpu_arg *arg = _arg;
+
+	__fib6_drop_pcpu_from(nh, arg->from, arg->table);
+	return 0;
+}
+
 static void fib6_drop_pcpu_from(struct fib6_info *f6i,
 				const struct fib6_table *table)
 {
-	struct fib6_nh *fib6_nh;
-
 	/* Make sure rt6_make_pcpu_route() wont add other percpu routes
 	 * while we are cleaning them here.
 	 */
 	f6i->fib6_destroying = 1;
 	mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */
 
-	fib6_nh = f6i->fib6_nh;
-	__fib6_drop_pcpu_from(fib6_nh, f6i, table);
+	if (f6i->nh) {
+		struct fib6_nh_pcpu_arg arg = {
+			.from = f6i,
+			.table = table
+		};
+
+		nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_drop_pcpu_from,
+					 &arg);
+	} else {
+		struct fib6_nh *fib6_nh;
+
+		fib6_nh = f6i->fib6_nh;
+		__fib6_drop_pcpu_from(fib6_nh, f6i, table);
+	}
 }
 
 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,