[Devel] [PATCH 06/16] net: Add a network namespace parameter to struct sock

[Denis V. Lunev]

Eric W. Biederman wrote:
> Sockets need to get a reference to their network namespace,
> or possibly a simple hold if someone registers on the network
> namespace notifier and will free the sockets when the namespace
> is going to be destroyed.
> 
> Signed-off-by: Eric W. Biederman <ebiederm at xmission.com>
> ---
>  include/net/inet_timewait_sock.h |    1 +
>  include/net/sock.h               |    3 +++
>  2 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
> index 47d52b2..abaff05 100644
> --- a/include/net/inet_timewait_sock.h
> +++ b/include/net/inet_timewait_sock.h
> @@ -115,6 +115,7 @@ struct inet_timewait_sock {
>  #define tw_refcnt		__tw_common.skc_refcnt
>  #define tw_hash			__tw_common.skc_hash
>  #define tw_prot			__tw_common.skc_prot
> +#define tw_net			__tw_common.skc_net


This place is a very tricky, indeed. If we keep the namespace until
timewait bucket death - we'll keep the namespace alive at least 5
_minutes_ after all process death.

If we stop a VE (in terms of OpenVz) and restart it, we'll 100% have an
_OLD_ namespace with all buckets shown :( So, in OpenVz we use a number
of VE instead of pointer to a VE. Additionally, on VE death we can wipe
all TW buckets. VE start stop from outside world looks very much like a
computer power on/off.

Regards,
	Den