Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756661AbZFJFip (ORCPT ); Wed, 10 Jun 2009 01:38:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752876AbZFJFie (ORCPT ); Wed, 10 Jun 2009 01:38:34 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:60458 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751448AbZFJFic (ORCPT ); Wed, 10 Jun 2009 01:38:32 -0400 Date: Tue, 9 Jun 2009 22:38:16 -0700 From: Andrew Morton To: Jesper Dangaard Brouer Cc: "David S. Miller" , "Paul E. McKenney" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, urs.thuermann@volkswagen.de, oliver.hartkopp@volkswagen.de, wg@grandegger.com, vladislav.yasevich@hp.com, sri@us.ibm.com, linux-sctp@vger.kernel.org, Trond.Myklebust@netapp.com, linux-nfs@vger.kernel.org, netfilter-devel@vger.kernel.org Subject: Re: [PATCH 2/5] nfnetlink_queue: Use rcu_barrier() on module unload. Message-Id: <20090609223816.af9b1bf9.akpm@linux-foundation.org> In-Reply-To: <20090608131133.10052.40836.stgit@localhost> References: <20090608130959.10052.54590.stgit@localhost> <20090608131133.10052.40836.stgit@localhost> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1801 Lines: 51 On Mon, 08 Jun 2009 15:11:33 +0200 Jesper Dangaard Brouer wrote: > This module uses rcu_call() thus it should use rcu_barrier() on module unload. > > Also fixed a trivial typo 'nfetlink' -> 'nfnetlink' in comment. > > Signed-off-by: Jesper Dangaard Brouer > --- > > net/netfilter/nfnetlink_queue.c | 4 +++- > 1 files changed, 3 insertions(+), 1 deletions(-) > > diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c > index 8c86011..71daa09 100644 > --- a/net/netfilter/nfnetlink_queue.c > +++ b/net/netfilter/nfnetlink_queue.c > @@ -1,6 +1,6 @@ > /* > * This is a module which is used for queueing packets and communicating with > - * userspace via nfetlink. > + * userspace via nfnetlink. > * > * (C) 2005 by Harald Welte > * (C) 2007 by Patrick McHardy > @@ -932,6 +932,8 @@ static void __exit nfnetlink_queue_fini(void) > #endif > nfnetlink_subsys_unregister(&nfqnl_subsys); > netlink_unregister_notifier(&nfqnl_rtnl_notifier); > + > + rcu_barrier(); /* Wait for completion of call_rcu()'s */ > } > > MODULE_DESCRIPTION("netfilter packet queue handler"); Possibly you've fixed the bug which the module_put(THIS_MODULE) in instance_destroy_rcu() is addressing. Do we still need to take a ref against the module for each instance once the above fix is in place? Nope, the THIS_MODULE games have been there since day one, and I can't work out why they're there. net/netfilter/nfnetlink_log.c has them too. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/