Re: [PATCH mptcp-net v2 3/3] mptcp: pm: avoid code duplication to lookup endp

[Geliang Tang <geliang@kernel.org>]

On Fri, 2024-10-25 at 18:37 +0800, Geliang Tang wrote:
> Hi Matt,
> 
> Thanks for this patch.
> 
> On Fri, 2024-10-25 at 11:32 +0200, Matthieu Baerts (NGI0) wrote:
> > From: Geliang Tang <tanggeliang@kylinos.cn>
> > 
> > The helper __lookup_addr_rcu() can be used in
> > mptcp_pm_nl_get_local_id()
> > and mptcp_pm_nl_is_backup() to simplify the code, and avoid code
> > duplication.
> > 
> > Co-developed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
> > Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
> > Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> > ---
> > Notes:
> >  - This is also for -next.
> > ---
> >  net/mptcp/pm_netlink.c | 20 ++++++--------------
> >  1 file changed, 6 insertions(+), 14 deletions(-)
> > 
> > diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
> > index
> > f38e1ccd34e95cd88b179a8b50e6965731542871..7c6e664b236d1659a554d003c
> > 78
> > c72ec91895ba5 100644
> > --- a/net/mptcp/pm_netlink.c
> > +++ b/net/mptcp/pm_netlink.c
> > @@ -1154,17 +1154,13 @@ int mptcp_pm_nl_get_local_id(struct
> > mptcp_sock *msk, struct mptcp_addr_info *skc
> >  {
> >  	struct mptcp_pm_addr_entry *entry;
> >  	struct pm_nl_pernet *pernet;
> > -	int ret = -1;
> > +	int ret;
> >  
> >  	pernet = pm_nl_get_pernet_from_msk(msk);
> >  
> >  	rcu_read_lock();
> > -	list_for_each_entry_rcu(entry, &pernet->local_addr_list,
> > list) {
> > -		if (mptcp_addresses_equal(&entry->addr, skc,
> > entry-
> > > addr.port)) {
> > -			ret = entry->addr.id;
> > -			break;
> > -		}
> > -	}
> > +	entry = __lookup_addr_rcu(pernet, skc);
> > +	ret = entry ? entry->addr.id : -1;
> >  	rcu_read_unlock();
> >  	if (ret >= 0)
> >  		return ret;
> > @@ -1191,15 +1187,11 @@ bool mptcp_pm_nl_is_backup(struct
> > mptcp_sock
> > *msk, struct mptcp_addr_info *skc)
> >  {
> >  	struct pm_nl_pernet *pernet =
> > pm_nl_get_pernet_from_msk(msk);
> >  	struct mptcp_pm_addr_entry *entry;
> > -	bool backup = false;
> > +	bool backup;
> >  
> >  	rcu_read_lock();
> > -	list_for_each_entry_rcu(entry, &pernet->local_addr_list,
> > list) {
> > -		if (mptcp_addresses_equal(&entry->addr, skc,
> > entry-
> > > addr.port)) {
> > -			backup = !!(entry->flags &
> > MPTCP_PM_ADDR_FLAG_BACKUP);
> > -			break;
> > -		}
> > -	}
> > +	entry = __lookup_addr_rcu(pernet, skc);
> > +	backup = entry && !!(entry->flags &
> > MPTCP_PM_ADDR_FLAG_BACKUP);
> 
> I think we should check whether entry is NULL here too. No?

Sorry, ignore my comment, your code is correct. :)

-Geliang

> 
> -Geliang
> 
> >  	rcu_read_unlock();
> >  
> >  	return backup;
> > 
> 
>