From: Jesper Dangaard Brouer Subject: Re: [PATCH 07/10] decnet: Use rcu_barrier() on module unload. Date: Wed, 24 Jun 2009 13:44:44 +0200 Message-ID: <1245843884.6695.54.camel@localhost.localdomain> References: <20090623150330.22490.87327.stgit@localhost> <20090623150429.22490.15113.stgit@localhost> <4A41C67E.8070301@googlemail.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , "Paul E. McKenney" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, dougthompson@xmission.com, bluesmoke-devel@lists.sourceforge.net, axboe@kernel.dk, Patrick McHardy , Trond.Myklebust@netapp.com, linux-wireless@vger.kernel.org, johannes@sipsolutions.net, yoshfuji@linux-ipv6.org, shemminger@linux-foundation.org, linux-nfs@vger.kernel.org, bfields@fieldses.org, neilb@suse.de, linux-ext4@vger.kernel.org, tytso@mit.edu, adilger@sun.com, netfilter-devel@vger.kernel.org To: Chrissie Caulfield Return-path: Received: from lanfw001a.cxnet.dk ([87.72.215.196]:47724 "EHLO lanfw001a.cxnet.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753382AbZFXLon (ORCPT ); Wed, 24 Jun 2009 07:44:43 -0400 In-Reply-To: <4A41C67E.8070301@googlemail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, 2009-06-24 at 07:23 +0100, Chrissie Caulfield wrote: > The issues with DECnet module unloading are a little more than just an > RCU leak I think! > > Though that area does need reviewing ... when I get some time. Fine. Now you have read my comment in the code, then there is a updated patch below. Will you ack-that? -- Med venlig hilsen / Best regards Jesper Brouer ComX Networks A/S Linux Network developer Cand. Scient Datalog / MSc. Author of http://adsl-optimizer.dk LinkedIn: http://www.linkedin.com/in/brouer [PATCH 07/10] decnet: Use rcu_barrier() on module unload. From: Jesper Dangaard Brouer The decnet module unloading as been disabled with a '#if 0' statement, because it have had issues. We add a rcu_barrier() anyhow for correctness. The maintainer (Chrissie Caulfield) will look into the unload issue when time permits. Signed-off-by: Jesper Dangaard Brouer --- net/decnet/af_decnet.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c index d351b8d..bff12da 100644 --- a/net/decnet/af_decnet.c +++ b/net/decnet/af_decnet.c @@ -2393,6 +2393,10 @@ module_init(decnet_init); * Prevent DECnet module unloading until its fixed properly. * Requires an audit of the code to check for memory leaks and * initialisation problems etc. + * + * hawk@comx.dk 2009-06-19: + * I have added a rcu_barrier() which should plug some of your + * module unload issues. Maintainers please try it out... */ #if 0 static void __exit decnet_exit(void) @@ -2413,6 +2417,8 @@ static void __exit decnet_exit(void) proc_net_remove(&init_net, "decnet"); proto_unregister(&dn_proto); + + rcu_barrier_bh(); /* Wait for completion of call_rcu_bh()'s */ } module_exit(decnet_exit); #endif