From: Jesper Dangaard Brouer Subject: [PATCH 10/10] nf_conntrack: Use rcu_barrier(). Date: Tue, 23 Jun 2009 17:04:44 +0200 Message-ID: <20090623150444.22490.27931.stgit@localhost> References: <20090623150330.22490.87327.stgit@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: Jesper Dangaard Brouer , "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" , christine.caulfield@googlemail.com, 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-xsfywfwIY+M@public.gmane.org, netfilter-devel@vger.kernel.org To: "David S. Miller" Return-path: In-Reply-To: <20090623150330.22490.87327.stgit@localhost> Sender: linux-wireless-owner@vger.kernel.org List-ID: I'm not sure which is are most optimal place to call rcu_barrier(). The patch probably calls rcu_barrier() too much, but its a better safe than sorry approach. There is embedded some comments that I would like Patrick McHardy to look at. Signed-off-by: Jesper Dangaard Brouer --- net/netfilter/nf_conntrack_core.c | 5 +++++ net/netfilter/nf_conntrack_standalone.c | 2 ++ 2 files changed, 7 insertions(+), 0 deletions(-) diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 5f72b94..cea4537 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1084,6 +1084,8 @@ static void nf_conntrack_cleanup_init_net(void) { nf_conntrack_helper_fini(); nf_conntrack_proto_fini(); + rcu_barrier(); + /* Need to wait for call_rcu() before dealloc the kmem_cache */ kmem_cache_destroy(nf_conntrack_cachep); } @@ -1118,6 +1120,9 @@ void nf_conntrack_cleanup(struct net *net) /* This makes sure all current packets have passed through netfilter framework. Roll on, two-stage module delete... */ + /* hawk-4UpuNZONu4c@public.gmane.org 2009-06-20: Think this should be replaced by a + rcu_barrier() ??? + */ synchronize_net(); nf_conntrack_cleanup_net(net); diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index 1935153..29c6cd0 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -500,6 +500,8 @@ static void nf_conntrack_net_exit(struct net *net) nf_conntrack_standalone_fini_sysctl(net); nf_conntrack_standalone_fini_proc(net); nf_conntrack_cleanup(net); + /* hawk-4UpuNZONu4c@public.gmane.org: Think rcu_barrier() should to be called earlier? */ + rcu_barrier(); /* Wait for completion of call_rcu()'s */ } static struct pernet_operations nf_conntrack_net_ops = {