From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH net-next-2.6] pppoe: RCU locking in get_item_by_addr() Date: Mon, 02 Nov 2009 06:51:22 +0100 Message-ID: <4AEE735A.4020601@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Linux Netdev List To: "David S. Miller" Return-path: Received: from gw1.cosmosbay.com ([212.99.114.194]:54721 "EHLO gw1.cosmosbay.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752051AbZKBFvY (ORCPT ); Mon, 2 Nov 2009 00:51:24 -0500 Sender: netdev-owner@vger.kernel.org List-ID: Note : this patch depends on dev_get_by_name_rcu(), not yet comitted. Thanks [PATCH net-next-2.6] pppoe: RCU locking in get_item_by_addr() Use dev_get_by_name_rcu() instead of dev_get_by_name(), to avoid touching device refcount in hotpath. Signed-off-by: Eric Dumazet --- drivers/net/pppoe.c | 19 +++++++++---------- 1 files changed, 9 insertions(+), 10 deletions(-) diff --git a/drivers/net/pppoe.c b/drivers/net/pppoe.c index 2559991..60c8d23 100644 --- a/drivers/net/pppoe.c +++ b/drivers/net/pppoe.c @@ -250,20 +250,19 @@ static inline struct pppox_sock *get_item_by_addr(struct net *net, { struct net_device *dev; struct pppoe_net *pn; - struct pppox_sock *pppox_sock; + struct pppox_sock *pppox_sock = NULL; int ifindex; - dev = dev_get_by_name(net, sp->sa_addr.pppoe.dev); - if (!dev) - return NULL; - - ifindex = dev->ifindex; - pn = net_generic(net, pppoe_net_id); - pppox_sock = get_item(pn, sp->sa_addr.pppoe.sid, + rcu_read_lock(); + dev = dev_get_by_name_rcu(net, sp->sa_addr.pppoe.dev); + if (dev) { + ifindex = dev->ifindex; + pn = net_generic(net, pppoe_net_id); + pppox_sock = get_item(pn, sp->sa_addr.pppoe.sid, sp->sa_addr.pppoe.remote, ifindex); - dev_put(dev); - + } + rcu_read_unlock(); return pppox_sock; }