Re: [PATCH net-next] rtnetlink: honor RTEXT_FILTER_SKIP_STATS in IFLA_STATS

From: Nicolas Dichtel

Date: Thu Oct 23 2025 - 11:39:12 EST


Le 23/10/2025 à 10:34, Adrian Moreno a écrit :
> Gathering interface statistics can be a relatively expensive operation
> on certain systems as it requires iterating over all the cpus.
>
> RTEXT_FILTER_SKIP_STATS was first introduced [1] to skip AF_INET6
> statistics from interface dumps and it was then extended [2] to
> also exclude IFLA_VF_INFO.
>
> The semantics of the flag does not seem to be limited to AF_INET
> or VF statistics and having a way to query the interface status
> (e.g: carrier, address) without retrieving its statistics seems
> reasonable. So this patch extends the use RTEXT_FILTER_SKIP_STATS
> to also affect IFLA_STATS.
>
> [1] https://lore.kernel.org/all/20150911204848.GC9687@xxxxxxxxxx/
> [2] https://lore.kernel.org/all/20230611105108.122586-1-gal@xxxxxxxxxx/
>
> Signed-off-by: Adrian Moreno <amorenoz@xxxxxxxxxx>
> ---
> net/core/rtnetlink.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index 8040ff7c356e..88d52157ef1c 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -2123,7 +2123,8 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
> if (rtnl_phys_switch_id_fill(skb, dev))
> goto nla_put_failure;
>
> - if (rtnl_fill_stats(skb, dev))
> + if (~ext_filter_mask & RTEXT_FILTER_SKIP_STATS &&
Maybe parentheses around this first condition?

The size could be adjusted accordingly in if_nlmsg_size().

> + rtnl_fill_stats(skb, dev))
> goto nla_put_failure;
>
> if (rtnl_fill_vf(skb, dev, ext_filter_mask))