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@kernel.org>
---
 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);
+}
+
+static int __init init_net_debugfs(void)
+{
+	ref_tracker_dir_debugfs(&init_net.refcnt_tracker);
+	ref_tracker_dir_debugfs(&init_net.notrefcnt_tracker);
+	net_ns_net_debugfs(&init_net);
+	return 0;
+}
+late_initcall(init_net_debugfs);
+#else
+static void net_ns_net_debugfs(struct net *net)
+{
+}
+#endif
+
 static __net_init int net_ns_net_init(struct net *net)
 {
+	int ret;
+
 #ifdef CONFIG_NET_NS
 	net->ns.ops = &netns_operations;
 #endif
-	return ns_alloc_inum(&net->ns);
+	ret = ns_alloc_inum(&net->ns);
+	if (!ret)
+		net_ns_net_debugfs(net);
+	return ret;
 }
 
 static __net_exit void net_ns_net_exit(struct net *net)

-- 
2.49.0

From: Jeff Layton <jlayton@kernel.org>
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@kernel.org>
> ---
>  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.

On Wed, 2025-04-30 at 14:29 -0700, Kuniyuki Iwashima wrote:
> From: Jeff Layton <jlayton@kernel.org>
> 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@kernel.org>
> > ---
> >  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.

My main use-case for this is to be able to match the inode number in
the /proc/<pid>/ns/net symlink with the correct ref_tracker debugfs
file. Is there a way to use the net_cookie to make that association?

If there isn't, and ns.inum is always 1 with procfs is disabled, we
could just skip adding the symlink when CONFIG_PROC_FS=n.
-- 
Jeff Layton <jlayton@kernel.org>

From: Jeff Layton <jlayton@kernel.org>
Date: Wed, 30 Apr 2025 19:59:23 -0700
> On Wed, 2025-04-30 at 14:29 -0700, Kuniyuki Iwashima wrote:
> > From: Jeff Layton <jlayton@kernel.org>
> > 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@kernel.org>
> > > ---
> > >  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.
> 
> My main use-case for this is to be able to match the inode number in
> the /proc/<pid>/ns/net symlink with the correct ref_tracker debugfs
> file. Is there a way to use the net_cookie to make that association?

It's roundabout, but  net_cookie can be retrieved by creating a
random socket in the netns and calling setsockopt(SO_NETNS_COOKIE).

Ido proposed a handy ip-netns subcommand here, and I guess it will
be implemented soon(?)
https://lore.kernel.org/netdev/1d99d7ccfc3a7a18840948ab6ba1c0b5fad90901.camel@fejes.dev/


> 
> If there isn't, and ns.inum is always 1 with procfs is disabled, we
> could just skip adding the symlink when CONFIG_PROC_FS=n.

On Wed, 2025-04-30 at 20:07 -0700, Kuniyuki Iwashima wrote:
> From: Jeff Layton <jlayton@kernel.org>
> Date: Wed, 30 Apr 2025 19:59:23 -0700
> > On Wed, 2025-04-30 at 14:29 -0700, Kuniyuki Iwashima wrote:
> > > From: Jeff Layton <jlayton@kernel.org>
> > > 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@kernel.org>
> > > > ---
> > > >  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.
> > 
> > My main use-case for this is to be able to match the inode number in
> > the /proc/<pid>/ns/net symlink with the correct ref_tracker debugfs
> > file. Is there a way to use the net_cookie to make that association?
> 
> It's roundabout, but  net_cookie can be retrieved by creating a
> random socket in the netns and calling setsockopt(SO_NETNS_COOKIE).
> 
> Ido proposed a handy ip-netns subcommand here, and I guess it will
> be implemented soon(?)
> https://lore.kernel.org/netdev/1d99d7ccfc3a7a18840948ab6ba1c0b5fad90901.camel@fejes.dev/

For the cases where I was looking at netns leaks, there were no more
processes in the container, so there was no way to enter the container
and spawn a socket at that point.

The point of the symlinks is to have a way to easily identify what
you're tracking. NAME_MAX is 255. We could do something like this
instead:

   snprintf(..., "netns-%u-%llx-refcnt", net->ns.inum, net->net_cookie);

Obviously the inums would all be 1 when PROC_FS=n, but the cookies
would be unique. Would that work?

> 
> > 
> > If there isn't, and ns.inum is always 1 with procfs is disabled, we
> > could just skip adding the symlink when CONFIG_PROC_FS=n.

-- 
Jeff Layton <jlayton@kernel.org>

From: Jeff Layton <jlayton@kernel.org>
Date: Wed, 30 Apr 2025 20:42:40 -0700
> On Wed, 2025-04-30 at 20:07 -0700, Kuniyuki Iwashima wrote:
> > From: Jeff Layton <jlayton@kernel.org>
> > Date: Wed, 30 Apr 2025 19:59:23 -0700
> > > On Wed, 2025-04-30 at 14:29 -0700, Kuniyuki Iwashima wrote:
> > > > From: Jeff Layton <jlayton@kernel.org>
> > > > 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@kernel.org>
> > > > > ---
> > > > >  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.
> > > 
> > > My main use-case for this is to be able to match the inode number in
> > > the /proc/<pid>/ns/net symlink with the correct ref_tracker debugfs
> > > file. Is there a way to use the net_cookie to make that association?
> > 
> > It's roundabout, but  net_cookie can be retrieved by creating a
> > random socket in the netns and calling setsockopt(SO_NETNS_COOKIE).
> > 
> > Ido proposed a handy ip-netns subcommand here, and I guess it will
> > be implemented soon(?)
> > https://lore.kernel.org/netdev/1d99d7ccfc3a7a18840948ab6ba1c0b5fad90901.camel@fejes.dev/
> 
> For the cases where I was looking at netns leaks, there were no more
> processes in the container, so there was no way to enter the container
> and spawn a socket at that point.

Then how do you get net->ns.inum ?


> 
> The point of the symlinks is to have a way to easily identify what
> you're tracking. NAME_MAX is 255. We could do something like this
> instead:
> 
>    snprintf(..., "netns-%u-%llx-refcnt", net->ns.inum, net->net_cookie);
> 
> Obviously the inums would all be 1 when PROC_FS=n, but the cookies
> would be unique. Would that work?

This works, but depending on the question above, there's no point in
using inum ?

On Wed, 2025-04-30 at 20:50 -0700, Kuniyuki Iwashima wrote:
> From: Jeff Layton <jlayton@kernel.org>
> Date: Wed, 30 Apr 2025 20:42:40 -0700
> > On Wed, 2025-04-30 at 20:07 -0700, Kuniyuki Iwashima wrote:
> > > From: Jeff Layton <jlayton@kernel.org>
> > > Date: Wed, 30 Apr 2025 19:59:23 -0700
> > > > On Wed, 2025-04-30 at 14:29 -0700, Kuniyuki Iwashima wrote:
> > > > > From: Jeff Layton <jlayton@kernel.org>
> > > > > 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@kernel.org>
> > > > > > ---
> > > > > >  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.
> > > > 
> > > > My main use-case for this is to be able to match the inode number in
> > > > the /proc/<pid>/ns/net symlink with the correct ref_tracker debugfs
> > > > file. Is there a way to use the net_cookie to make that association?
> > > 
> > > It's roundabout, but  net_cookie can be retrieved by creating a
> > > random socket in the netns and calling setsockopt(SO_NETNS_COOKIE).
> > > 
> > > Ido proposed a handy ip-netns subcommand here, and I guess it will
> > > be implemented soon(?)
> > > https://lore.kernel.org/netdev/1d99d7ccfc3a7a18840948ab6ba1c0b5fad90901.camel@fejes.dev/
> > 
> > For the cases where I was looking at netns leaks, there were no more
> > processes in the container, so there was no way to enter the container
> > and spawn a socket at that point.
> 
> Then how do you get net->ns.inum ?
> 

In my case, I was looking at /sys/kernel/debug/sunrpc/rpc_xprt/*/info.
That also displays net->ns.inum in the same format. When I was
originally working on this, the problem I was chasing was due to stuck
RPC transports (rpc_xprt).


> 
> > 
> > The point of the symlinks is to have a way to easily identify what
> > you're tracking. NAME_MAX is 255. We could do something like this
> > instead:
> > 
> >    snprintf(..., "netns-%u-%llx-refcnt", net->ns.inum, net->net_cookie);
> > 
> > Obviously the inums would all be 1 when PROC_FS=n, but the cookies
> > would be unique. Would that work?
> 
> This works, but depending on the question above, there's no point in
> using inum ?

Having the inum is definitely useful to me, particularly since the
net_cookie would be pretty useless for the problems I've been chasing.
 
I'll plan to respin this to include the net_cookie though, since that
would disambiguate the names when PROC_FS=n. It might also turn out to
be useful for someone, once there is a way to fetch the net_cookie from
userland. 
-- 
Jeff Layton <jlayton@kernel.org>

From: Jeff Layton <jlayton@kernel.org>
Date: Wed, 30 Apr 2025 21:07:20 -0700
> On Wed, 2025-04-30 at 20:50 -0700, Kuniyuki Iwashima wrote:
> > From: Jeff Layton <jlayton@kernel.org>
> > Date: Wed, 30 Apr 2025 20:42:40 -0700
> > > On Wed, 2025-04-30 at 20:07 -0700, Kuniyuki Iwashima wrote:
> > > > From: Jeff Layton <jlayton@kernel.org>
> > > > Date: Wed, 30 Apr 2025 19:59:23 -0700
> > > > > On Wed, 2025-04-30 at 14:29 -0700, Kuniyuki Iwashima wrote:
> > > > > > From: Jeff Layton <jlayton@kernel.org>
> > > > > > 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@kernel.org>
> > > > > > > ---
> > > > > > >  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.
> > > > > 
> > > > > My main use-case for this is to be able to match the inode number in
> > > > > the /proc/<pid>/ns/net symlink with the correct ref_tracker debugfs
> > > > > file. Is there a way to use the net_cookie to make that association?
> > > > 
> > > > It's roundabout, but  net_cookie can be retrieved by creating a
> > > > random socket in the netns and calling setsockopt(SO_NETNS_COOKIE).
> > > > 
> > > > Ido proposed a handy ip-netns subcommand here, and I guess it will
> > > > be implemented soon(?)
> > > > https://lore.kernel.org/netdev/1d99d7ccfc3a7a18840948ab6ba1c0b5fad90901.camel@fejes.dev/
> > > 
> > > For the cases where I was looking at netns leaks, there were no more
> > > processes in the container, so there was no way to enter the container
> > > and spawn a socket at that point.
> > 
> > Then how do you get net->ns.inum ?
> > 
> 
> In my case, I was looking at /sys/kernel/debug/sunrpc/rpc_xprt/*/info.
> That also displays net->ns.inum in the same format. When I was
> originally working on this, the problem I was chasing was due to stuck
> RPC transports (rpc_xprt).

Thanks for the info.

Prefarably the debugfs should also display netns_cookie instaed of inum,
and the change is acceptable as the debugfs is not uAPI.

Then we don't need to expose possibly non-unique value just for historical
reason.


> 
> 
> > 
> > > 
> > > The point of the symlinks is to have a way to easily identify what
> > > you're tracking. NAME_MAX is 255. We could do something like this
> > > instead:
> > > 
> > >    snprintf(..., "netns-%u-%llx-refcnt", net->ns.inum, net->net_cookie);
> > > 
> > > Obviously the inums would all be 1 when PROC_FS=n, but the cookies
> > > would be unique. Would that work?
> > 
> > This works, but depending on the question above, there's no point in
> > using inum ?
> 
> Having the inum is definitely useful to me, particularly since the
> net_cookie would be pretty useless for the problems I've been chasing.
>  
> I'll plan to respin this to include the net_cookie though, since that
> would disambiguate the names when PROC_FS=n. It might also turn out to
> be useful for someone, once there is a way to fetch the net_cookie from
> userland. 
> --