Re: [PATCH net-next 08/17] netdevsim: Adjust accounting for IPv6 multipath notifications

[David Ahern <dsahern@gmail.com>]

On 6/15/19 8:07 AM, Ido Schimmel wrote:
> diff --git a/drivers/net/netdevsim/fib.c b/drivers/net/netdevsim/fib.c
> index 83ba5113210d..6e5498ef3855 100644
> --- a/drivers/net/netdevsim/fib.c
> +++ b/drivers/net/netdevsim/fib.c
> @@ -137,19 +137,20 @@ static int nsim_fib_rule_event(struct nsim_fib_data *data,
>  }
>  
>  static int nsim_fib_account(struct nsim_fib_entry *entry, bool add,
> +			    unsigned int num_rt,
>  			    struct netlink_ext_ack *extack)
>  {
>  	int err = 0;
>  
>  	if (add) {
> -		if (entry->num < entry->max) {
> -			entry->num++;
> +		if (entry->num + num_rt < entry->max) {
> +			entry->num += num_rt;
>  		} else {
>  			err = -ENOSPC;
>  			NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported fib entries");
>  		}
>  	} else {
> -		entry->num--;
> +		entry->num -= num_rt;
>  	}
>  
>  	return err;
> @@ -159,14 +160,20 @@ static int nsim_fib_event(struct nsim_fib_data *data,
>  			  struct fib_notifier_info *info, bool add)
>  {
>  	struct netlink_ext_ack *extack = info->extack;
> +	struct fib6_entry_notifier_info *fen6_info;
> +	unsigned int num_rt = 1;
>  	int err = 0;
>  
>  	switch (info->family) {
>  	case AF_INET:
> -		err = nsim_fib_account(&data->ipv4.fib, add, extack);
> +		err = nsim_fib_account(&data->ipv4.fib, add, num_rt, extack);
>  		break;
>  	case AF_INET6:
> -		err = nsim_fib_account(&data->ipv6.fib, add, extack);
> +		fen6_info = container_of(info, struct fib6_entry_notifier_info,
> +					 info);
> +		if (fen6_info->multipath_rt)
> +			num_rt = fen6_info->nsiblings + 1;
> +		err = nsim_fib_account(&data->ipv6.fib, add, num_rt, extack);

The intention of the original patch was to account for a multipath route
as 1 entry, not N where N is the number of paths.