From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lennart Poettering Subject: Re: [PATCH cgroup/for-3.11] cgroup: disallow rename(2) if sane_behavior Date: Sun, 16 Jun 2013 09:16:48 +0200 Message-ID: <20130616071648.GA1978@tango.0pointer.de> References: <20130614034717.GA31533@htj.dyndns.org> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20130614034717.GA31533-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tejun Heo Cc: Li Zefan , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Daniel P. Berrange" , Kay Sievers On Thu, 13.06.13 20:47, Tejun Heo (tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org) wrote: > cgroup's rename(2) isn't a proper migration implementation - it can't > move the cgroup to a different parent in the hierarchy. All it can do > is swapping the name string for that cgroup. This isn't useful and > can mislead users to think that cgroup supports proper cgroup-level > migration. Disallow rename(2) if sane_behavior. Note that in the long run I'd really like to see functionality added to move a full cgroup subtree to a different point in the tree, so that we can migrate containers and such atomically from one partition to another, without the container having to be aware of this (which of course implies that we have a somewhat more useful cgroup namespacing solution in place). Lennart -- Lennart Poettering - Red Hat, Inc.