From patchwork Tue Jun 23 15:03:59 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jesper Dangaard Brouer X-Patchwork-Id: 29060 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@bilbo.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 95638B70C2 for ; Wed, 24 Jun 2009 01:04:34 +1000 (EST) Received: by ozlabs.org (Postfix) id 86AC3DDDF4; Wed, 24 Jun 2009 01:04:34 +1000 (EST) Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id 0CD0CDDDA2 for ; Wed, 24 Jun 2009 01:04:34 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759575AbZFWPEC (ORCPT ); Tue, 23 Jun 2009 11:04:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760252AbZFWPEB (ORCPT ); Tue, 23 Jun 2009 11:04:01 -0400 Received: from lanfw001a.cxnet.dk ([87.72.215.196]:36328 "EHLO lanfw001a.cxnet.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760155AbZFWPD5 (ORCPT ); Tue, 23 Jun 2009 11:03:57 -0400 Received: from hotlava.cxnet.dk (unknown [172.31.4.152]) by lanfw001a.cxnet.dk (Postfix) with ESMTP id 1F31916362A; Tue, 23 Jun 2009 17:03:59 +0200 (CEST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by hotlava.cxnet.dk (Postfix) with ESMTP id 0CAD345C068; Tue, 23 Jun 2009 17:03:59 +0200 (CEST) From: Jesper Dangaard Brouer Subject: [PATCH 01/10] ext4: Use rcu_barrier() on module unload. To: "David S. Miller" 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@sun.com, netfilter-devel@vger.kernel.org Date: Tue, 23 Jun 2009 17:03:59 +0200 Message-ID: <20090623150358.22490.24818.stgit@localhost> In-Reply-To: <20090623150330.22490.87327.stgit@localhost> References: <20090623150330.22490.87327.stgit@localhost> User-Agent: StGIT/0.14.2 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The ext4 module uses rcu_call() thus it should use rcu_barrier()on module unload. The kmem cache ext4_pspace_cachep is sometimes free'ed using call_rcu() callbacks. Thus, we must wait for completion of call_rcu() before doing kmem_cache_destroy(). I have difficult determining if no new call_rcu() callbacks can be envoked. Would the maintainer please verify this? Signed-off-by: Jesper Dangaard Brouer --- fs/ext4/mballoc.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 519a0a6..e271a9e 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2902,8 +2902,10 @@ int __init init_ext4_mballoc(void) void exit_ext4_mballoc(void) { - /* XXX: synchronize_rcu(); */ + /* Wait for completion of call_rcu()'s on ext4_pspace_cachep */ + rcu_barrier(); kmem_cache_destroy(ext4_pspace_cachep); + kmem_cache_destroy(ext4_ac_cachep); kmem_cache_destroy(ext4_free_ext_cachep); }