Re: [Patch 0/3] posix mqueue namespace (v14)

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 16 Jan 2009 20:02:48 -0600
"Serge E. Hallyn" <serue@us.ibm.com> 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?