Re: [PATCH nf-next 1/3] ipvs: show the current conn_tab size to users

Julian Anastasov <[email protected]> wrote:
> As conn_tab is per-net, better to show the current hash table size
> to users instead of the ip_vs_conn_tab_size (max).
> 
> Signed-off-by: Julian Anastasov <[email protected]>
> ---
>  net/netfilter/ipvs/ip_vs_ctl.c | 26 ++++++++++++++++++++++----
>  1 file changed, 22 insertions(+), 4 deletions(-)
> 
> diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
> index b472e564b769..3129b15dadc2 100644
> --- a/net/netfilter/ipvs/ip_vs_ctl.c
> +++ b/net/netfilter/ipvs/ip_vs_ctl.c
> @@ -281,6 +281,13 @@ static void est_reload_work_handler(struct work_struct *work)
>  	mutex_unlock(&ipvs->est_mutex);
>  }
>  
> +static int get_conn_tab_size(struct netns_ipvs *ipvs)
> +{
> +	struct ip_vs_rht *t = rcu_dereference(ipvs->conn_tab);
> +
> +	return t? t->size : 0;
> +}

Pablo suggest to make this self-contained so callers don't have to
handle rcu read lock:

static int get_conn_tab_size(struct netns_ipvs *ipvs)
{
	const struct ip_vs_rht *t;
	int size = 0;

	rcu_read_lock();
	t = rcu_dereference(ipvs->conn_tab);
	if (t)
		size = t->size;
	rcu_read_unlock();

	return size;
}