Re: [PATCH v2 net-next 6/9] l2tp: use get_next APIs for management requests and procfs/debugfs

[Cong Wang <xiyou.wangcong@gmail.com>]

On Mon, Aug 12, 2024 at 09:14:42AM +0100, James Chapman wrote:
> On 11/08/2024 19:36, Cong Wang wrote:
> > On Wed, Aug 07, 2024 at 07:54:49AM +0100, James Chapman wrote:
> > > diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
> > > index cc464982a7d9..0fabacffc3f3 100644
> > > --- a/net/l2tp/l2tp_core.h
> > > +++ b/net/l2tp/l2tp_core.h
> > > @@ -219,14 +219,12 @@ void l2tp_session_dec_refcount(struct l2tp_session *session);
> > >    * the caller must ensure that the reference is dropped appropriately.
> > >    */
> > >   struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
> > > -struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth);
> > >   struct l2tp_tunnel *l2tp_tunnel_get_next(const struct net *net, unsigned long *key);
> > >   struct l2tp_session *l2tp_v3_session_get(const struct net *net, struct sock *sk, u32 session_id);
> > >   struct l2tp_session *l2tp_v2_session_get(const struct net *net, u16 tunnel_id, u16 session_id);
> > >   struct l2tp_session *l2tp_session_get(const struct net *net, struct sock *sk, int pver,
> > >   				      u32 tunnel_id, u32 session_id);
> > > -struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth);
> > >   struct l2tp_session *l2tp_session_get_next(const struct net *net, struct sock *sk, int pver,
> > >   					   u32 tunnel_id, unsigned long *key);
> > >   struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
> > > diff --git a/net/l2tp/l2tp_debugfs.c b/net/l2tp/l2tp_debugfs.c
> > > index 8755ae521154..b2134b57ed18 100644
> > > --- a/net/l2tp/l2tp_debugfs.c
> > > +++ b/net/l2tp/l2tp_debugfs.c
> > > @@ -34,8 +34,8 @@ static struct dentry *rootdir;
> > >   struct l2tp_dfs_seq_data {
> > >   	struct net	*net;
> > >   	netns_tracker	ns_tracker;
> > > -	int tunnel_idx;			/* current tunnel */
> > > -	int session_idx;		/* index of session within current tunnel */
> > > +	unsigned long tkey;		/* lookup key of current tunnel */
> > > +	unsigned long skey;		/* lookup key of current session */
> > 
> > Any reason to change the type from int to unsigned long?
> > 
> > Asking because tunnel ID remains to be 32bit unsigned int as a part of
> > UAPI.
> > 
> > Thanks.
> 
> It's used as the key in and potentially modified by idr_get_next_ul calls.

idr_get_next() takes an `int` ID. So the reason is not this API, it must be
something else.