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

["Serge E. Hallyn" <serue@us.ibm.com>]

Quoting 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?

Everyone using posix mq with an -mm kernel :)

There are ltp testcases which I hope can be pushed once these
patches appear headed upstream.

thanks,
-serge