From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [Patch 0/3] posix mqueue namespace (v14) Date: Mon, 26 Jan 2009 15:28:32 -0800 Message-ID: <20090126152832.1918efed.akpm@linux-foundation.org> References: <20090117020248.GA8615@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090117020248.GA8615@us.ibm.com> Sender: linux-kernel-owner@vger.kernel.org To: "Serge E. Hallyn" Cc: linux-kernel@vger.kernel.org, containers@lists.osdl.org List-Id: containers.vger.kernel.org On Fri, 16 Jan 2009 20:02:48 -0600 "Serge E. Hallyn" wrote: > IPC namespaces are completely disjoint id->object mappings. > A task can pass CLONE_NEWIPC to unshare and clone to get > a new, empty, IPC namespace. Until now this has supported > SYSV IPC. > > Most Posix IPC is done in userspace. The posix mqueue > support, however, is implemented on top of the mqueue fs. > > This patchset implements multiple mqueue fs instances, > one per IPC namespace to be precise. > > To create a new ipc namespace with posix mq support, you > should now: > > unshare(CLONE_NEWIPC|CLONE_NEWNS); > umount /dev/mqueue > mount -t mqueue mqueue /dev/mqueue > > It's perfectly valid to do vfs operations on files > in another ipc_namespace's /dev/mqueue, but any use > of mq_open(3) and friends will act in your own ipc_ns. > After the ipc namespace has exited, you can still > unlink but no longer create files in that fs (since > accounting is carried. > > Changelog: > v14: (Jan 16 2009) port to linux-next > v13: (Dec 28 2009) > 1. addressed comments by Dave and Suka > 2. ported Cedric's patch to make posix mq sysctls > per-namespace > > When convenient, it would be great to see this tested > in -mm. hm. Who is going to test it?