Re: [PATCH v6 08/10] net: add symlinks to ref_tracker_dir for netns

[Kuniyuki Iwashima]

From: Jeff Layton <jlayton@xxxxxxxxxx>
Date: Wed, 30 Apr 2025 08:06:54 -0700
> After assigning the inode number to the namespace, use it to create a
> unique name for each netns refcount tracker with the ns.inum value in
> it, and register a symlink to the debugfs file for it.
> 
> init_net is registered before the ref_tracker dir is created, so add a
> late_initcall() to register its files and symlinks.
> 
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
>  net/core/net_namespace.c | 28 +++++++++++++++++++++++++++-
>  1 file changed, 27 insertions(+), 1 deletion(-)
> 
> diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
> index 008de9675ea98fa8c18628b2f1c3aee7f3ebc9c6..6cbc8eabb8e56c847fc34fa8ec9994e8b275b0af 100644
> --- a/net/core/net_namespace.c
> +++ b/net/core/net_namespace.c
> @@ -763,12 +763,38 @@ struct net *get_net_ns_by_pid(pid_t pid)
>  }
>  EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
>  
> +#ifdef CONFIG_NET_NS_REFCNT_TRACKER
> +static void net_ns_net_debugfs(struct net *net)
> +{
> +	ref_tracker_dir_symlink(&net->refcnt_tracker, "netns-%u-refcnt", net->ns.inum);
> +	ref_tracker_dir_symlink(&net->notrefcnt_tracker, "netns-%u-notrefcnt", net->ns.inum);

Could you use net->net_cookie ?

net->ns.inum is always 1 when CONFIG_PROC_FS=n.