From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755793Ab2CTQtW (ORCPT ); Tue, 20 Mar 2012 12:49:22 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:43939 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753062Ab2CTQtU (ORCPT ); Tue, 20 Mar 2012 12:49:20 -0400 Date: Tue, 20 Mar 2012 09:49:15 -0700 From: Tejun Heo To: Glauber Costa Cc: lizf@cn.fujitsu.com, containers@lists.linux-foundation.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, fweisbec@gmail.com, rni@google.com, ctalbott@google.com Subject: Re: [PATCH 09/10] cgroup: introduce struct cfent Message-ID: <20120320164915.GF5684@google.com> References: <1331940963-15756-1-git-send-email-tj@kernel.org> <1331940963-15756-10-git-send-email-tj@kernel.org> <4F688EA9.8050905@parallels.com> <20120320160228.GD5684@google.com> <4F68AA37.80604@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F68AA37.80604@parallels.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 20, 2012 at 08:03:03PM +0400, Glauber Costa wrote: > From 04604201411ab0a14fa1447072cd1b273d0774ed Mon Sep 17 00:00:00 2001 > From: Glauber Costa > Date: Tue, 20 Mar 2012 18:12:55 +0400 > Subject: [PATCH] don't trigger warning when d_subdirs is not empty. > > It is never empty at this point, because of the self references. > a better test is to see if any of them gets d_inode set. > > Signed-off-by: Glauber Costa > Signed-off-by: Tejun Heo > --- > kernel/cgroup.c | 8 +++++++- > 1 files changed, 7 insertions(+), 1 deletions(-) > > diff --git a/kernel/cgroup.c b/kernel/cgroup.c > index cf7b298..b45a653 100644 > --- a/kernel/cgroup.c > +++ b/kernel/cgroup.c > @@ -947,10 +947,16 @@ static int cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft) > static void cgroup_clear_directory(struct dentry *dir) > { > struct cgroup *cgrp = __d_cgrp(dir); > + struct list_head *child; > > while (!list_empty(&cgrp->files)) > cgroup_rm_file(cgrp, NULL); > - WARN_ON_ONCE(!list_empty(&dir->d_subdirs)); > + > + list_for_each(child, &dir->d_subdirs) { > + struct dentry *d; > + d = list_entry(child, struct dentry, d_u.d_child); > + WARN_ON_ONCE(d->d_inode); > + } This seems correct and I'll apply this but I still can't reproduce the warning at will before the patch. How do I a get negative dentry on the d_subdirs when d_delete always returns 1? Glauber, can you trigger the warning at will? Thanks. -- tejun