From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [PATCH net-next] net: core: Traverse the adjacency list from first entry Date: Wed, 26 Oct 2016 09:05:35 -0600 Message-ID: <0ddd89b6-a9ec-29b5-2e0a-18d11fac5e4e@cumulusnetworks.com> References: <1477463962-2802-1-git-send-email-idosch@idosch.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, mlxsw@mellanox.com, Ido Schimmel To: idosch@idosch.org, davem@davemloft.net Return-path: Received: from mail-pf0-f170.google.com ([209.85.192.170]:33861 "EHLO mail-pf0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932601AbcJZPFi (ORCPT ); Wed, 26 Oct 2016 11:05:38 -0400 Received: by mail-pf0-f170.google.com with SMTP id n85so24738458pfi.1 for ; Wed, 26 Oct 2016 08:05:38 -0700 (PDT) In-Reply-To: <1477463962-2802-1-git-send-email-idosch@idosch.org> Sender: netdev-owner@vger.kernel.org List-ID: On 10/26/16 12:39 AM, idosch@idosch.org wrote: > From: Ido Schimmel > > netdev_next_lower_dev() returns NULL when we finished traversing the > adjacency list ('iter' points to the list's head). Therefore, we must > start traversing the list from the first entry and not its head. > > Fixes: 1a3f060c1a47 ("net: Introduce new api for walking upper and lower devices") > Signed-off-by: Ido Schimmel > --- > net/core/dev.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/core/dev.c b/net/core/dev.c > index f55fb45..d9c937f 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -5419,7 +5419,7 @@ int netdev_walk_all_lower_dev(struct net_device *dev, > struct list_head *iter; > int ret; > > - for (iter = &dev->adj_list.lower, > + for (iter = dev->adj_list.lower.next, > ldev = netdev_next_lower_dev(dev, &iter); > ldev; > ldev = netdev_next_lower_dev(dev, &iter)) { > How about this instead? It keeps the 3 walk functions in sync modulo the rcu reference: diff --git a/net/core/dev.c b/net/core/dev.c index f55fb4536016..6aa43cd8cbb5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5400,12 +5400,12 @@ static struct net_device *netdev_next_lower_dev(struct net_device *dev, { struct netdev_adjacent *lower; - lower = list_entry(*iter, struct netdev_adjacent, list); + lower = list_entry((*iter)->next, struct netdev_adjacent, list); if (&lower->list == &dev->adj_list.lower) return NULL; - *iter = lower->list.next; + *iter = &lower->list; return lower->dev; }