From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aristeu Rozanski Subject: Re: [PATCH v5 9/9] devcg: propagate local changes down the hierarchy Date: Mon, 4 Feb 2013 10:09:30 -0500 Message-ID: <20130204150930.GR17632@redhat.com> References: <20130130171101.060853036@napanee.usersys.redhat.com> <20130130171102.390708521@napanee.usersys.redhat.com> <20130131043839.GA14726@mail.hallyn.com> <20130201190958.GP17632@redhat.com> <20130202162052.GB11284@mail.hallyn.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20130202162052.GB11284-7LNsyQBKDXoIagZqoN9o3w@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Serge E. Hallyn" Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Tejun Heo , Serge Hallyn On Sat, Feb 02, 2013 at 04:20:52PM +0000, Serge E. Hallyn wrote: > Quoting Aristeu Rozanski (aris-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org): > > +static int propagate_exception(struct dev_cgroup *devcg_root) > > +{ > > + struct cgroup *root = devcg_root->css.cgroup; > > + struct dev_cgroup *devcg, *parent, *tmp; > > + int rc = 0; > > + LIST_HEAD(pending); > > + > > + get_online_devcg(root, &pending); > > + > > + list_for_each_entry_safe(devcg, tmp, &pending, propagate_pending) { > > + parent = cgroup_to_devcgroup(devcg->css.cgroup->parent); > > + > > + dev_exception_clean(&devcg->exceptions); > > + if (devcg->behavior == parent->behavior) { > > + rc = dev_exceptions_copy(&devcg->exceptions, &parent->exceptions); > > Let's say parent A and child B both have DEFAULT_DENY, with a set of let's > say 5 whitelist exceptions. Now the parent adds two more whitelist > exceptions. As you say, we don't propagate those. > > Now the parent removes one of it's whitelist exceptions. > devcgroup_update_access() calls dev_exception_rm() followed by > propagate_exception(), which comes here and copies the parent's > whitelist - including the two new whitelist rules - to the > child. ugh, I see your point. This gonna be trickier to fix. -- Aristeu