Subject: Re: [RFC PATCH net-next V2] net: split rt_genid for ipv4 and ipv6

From: Nicolas Dichtel <[email-masked]>
Date: Tue, 23 Jul 2013 23:51:53 +0200

Le 23/07/2013 03:37, Fan Du a écrit :
> Current net name space has only one genid for both IPv4 and IPv6, it has below drawbacks:
>
> - Add/delete an IPv4 address will invalidate all IPv6 routing table entries.
> - Insert/remove XFRM policy will also invalidate both IPv4/IPv6 routing table entries
>    even when the policy is only applied for one address family.
>
> Thus, this patch attempt to split one genid for two to cater for IPv4 and IPv6 separately
> in a fine granularity.
>
> Signed-off-by: Fan Du <[email-masked]>
>
> V2:
>   -Fix compile issue when IPv6 not enabled
>   -Put genid into struct netns_ipv4/ipv6
> ---
>   include/net/net_namespace.h |   39 ++++++++++++++++++++++++++++++++++-----
>   include/net/netns/ipv4.h    |    1 +
>   include/net/netns/ipv6.h    |    1 +
>   net/ipv4/route.c            |   16 ++++++++--------
>   net/ipv6/af_inet6.c         |    1 +
>   net/ipv6/route.c            |    4 ++--
>   net/xfrm/xfrm_policy.c      |    8 +++++++-
>   7 files changed, 54 insertions(+), 16 deletions(-)
>
> diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
> index 84e37b1..763e63f 100644
> --- a/include/net/net_namespace.h
> +++ b/include/net/net_namespace.h
> @@ -119,7 +119,6 @@ struct net {
>   	struct netns_ipvs	*ipvs;
>   #endif
>   	struct sock		*diag_nlsk;
> -	atomic_t		rt_genid;
>   	atomic_t		fnhe_genid;
>   };
>
> @@ -333,14 +332,44 @@ static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
>   }
>   #endif
>
> -static inline int rt_genid(struct net *net)
> +static inline int rt_genid_ipv4(struct net *net)
>   {
> -	return atomic_read(&net->rt_genid);
> +	return atomic_read(&net->ipv4.rt_genid_ipv4);
>   }
>
> -static inline void rt_genid_bump(struct net *net)
> +static inline void rt_genid_bump_ipv4(struct net *net)
>   {
> -	atomic_inc(&net->rt_genid);
> +	atomic_inc(&net->ipv4.rt_genid_ipv4);
> +}
> +
> +#if IS_ENABLED(CONFIG_IPV6)
> +static inline int rt_genid_ipv6(struct net *net)
> +{
> +	return atomic_read(&net->ipv6.rt_genid_ipv6);
> +}
> +
> +static inline void rt_genid_bump_ipv6(struct net *net)
> +{
> +	atomic_inc(&net->ipv6.rt_genid_ipv6);
> +}
> +#else
> +static inline int rt_genid_ipv6(struct net *net)
> +{
> +	return 0;
> +}
> +
> +static inline void rt_genid_bump_ipv6(struct net *net)
> +{
> +}
> +#endif
> +
> +/* For callers who don't really care about whether it's IPv4 or IPv6 */
> +static inline void rt_genid_bump_all(struct net *net)
> +{
> +	atomic_inc(&net->ipv4.rt_genid_ipv4);
> +#if IS_ENABLED(CONFIG_IPV6)
> +	atomic_inc(&net->ipv6.rt_genid_ipv6);
> +#endif
>   }
>
>   static inline int fnhe_genid(struct net *net)
> diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
> index 2ba9de8..d87af01 100644
> --- a/include/net/netns/ipv4.h
> +++ b/include/net/netns/ipv4.h
> @@ -77,5 +77,6 @@ struct netns_ipv4 {
>   	struct fib_rules_ops	*mr_rules_ops;
>   #endif
>   #endif
> +	atomic_t	rt_genid_ipv4;
Just nitpiking: maybe _ipv4 is redundant? It's already in 'struct netns_ipv4'.
Same for IPv6.