Re: [PATCH net-next 01/10] netdevsim: fib: Convert the current occupancy to an atomic variable

@@ -889,22 +882,29 @@ static void nsim_nexthop_destroy(struct nsim_nexthop *nexthop)
 static int nsim_nexthop_account(struct nsim_fib_data *data, u64 occ,
 				bool add, struct netlink_ext_ack *extack)
 {
-	int err = 0;
+	int i, err = 0;
 
 	if (add) {
-		if (data->nexthops.num + occ <= data->nexthops.max) {
-			data->nexthops.num += occ;
-		} else {
-			err = -ENOSPC;
-			NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported nexthops");
-		}
+		for (i = 0; i < occ; i++)
+			if (!atomic64_add_unless(&data->nexthops.num, 1,
+						 data->nexthops.max)) {

+				err = -ENOSPC;
+				NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported nexthops");
+				goto err_num_decrease;
+			}
 	} else {
-		if (WARN_ON(occ > data->nexthops.num))
+		if (WARN_ON(occ > atomic64_read(&data->nexthops.num)))
 			return -EINVAL;
-		data->nexthops.num -= occ;
+		atomic64_sub(occ, &data->nexthops.num);
 	}
 
 	return err;
+
+err_num_decrease:
+	for (i--; i >= 0; i--)
+		atomic64_dec(&data->nexthops.num);

+	return err;
+
 }
 
 static int nsim_nexthop_add(struct nsim_fib_data *data,