From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH v4 3/3] Send cgroup_path in SCM_CGROUP Date: Mon, 13 Jan 2014 11:52:53 -0500 Message-ID: <20140113165253.GC29053@htj.dyndns.org> References: <1377614400-27122-1-git-send-email-jkaluza@redhat.com> <1389600109-30739-1-git-send-email-jkaluza@redhat.com> <1389600109-30739-4-git-send-email-jkaluza@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: rgb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, LKML , eparis-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org To: Jan Kaluza Return-path: Content-Disposition: inline In-Reply-To: <1389600109-30739-4-git-send-email-jkaluza-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: netdev.vger.kernel.org On Mon, Jan 13, 2014 at 09:01:49AM +0100, Jan Kaluza wrote: > Server-like processes in many cases need credentials and other > metadata of the peer, to decide if the calling process is allowed to > request a specific action, or the server just wants to log away this > type of information for auditing tasks. > > The current practice to retrieve such process metadata is to look that > information up in procfs with the $PID received over SCM_CREDENTIALS. > This is sufficient for long-running tasks, but introduces a race which > cannot be worked around for short-living processes; the calling > process and all the information in /proc/$PID/ is gone before the > receiver of the socket message can look it up. > > This introduces a new SCM type called SCM_CGROUP to allow the direct > attaching of "cgroup_path" to SCM, which is significantly more > efficient and will reliably avoid the race with the round-trip over > procfs. > > Signed-off-by: Jan Kaluza For cgroup related part: Acked-by: Tejun Heo Thanks. -- tejun