[Devel] Re: [PATCH 1/2][RFC] containers: improve automatic container naming

[Serge E. Hallyn]

Quoting Andrew Morton (akpm at linux-foundation.org):
> On Fri, 1 Jun 2007 16:48:09 -0500
> "Serge E. Hallyn" <serue at us.ibm.com> wrote:
> 
> > This compiles and boots, but is not intended for inclusion in -mm (yet),
> > just as an RFC for the naming scheme to fix the bug Andrew pointed out.
> > 
> > Seem ok overall?
> > 
> > thanks,
> > -serge
> > 
> > >From 8e9b972f7482415777e982d3bc9a0d55cbaf862b Mon Sep 17 00:00:00 2001
> > From: Serge E. Hallyn <serue at us.ibm.com>
> > Date: Fri, 1 Jun 2007 15:32:15 -0400
> > Subject: [PATCH 1/2] containers: improve automatic container naming
> > 
> > The automatic naming of containers created using container_clone()
> > is currently broken (not protected from wraparound) and inconvenient.
> > 
> > Add a per-container counter for use in naming children of the container.
> > Before two unshares in a row by one process, and a third in another,
> > would result in
> > 
> > 	/node1/node2
> > 	/node3
> > 
> > The current scheme should result in
> > 
> > 	/node1/node1
> > 	/node2
> > 
> > Also, keep a hash table populated with used names, to protect
> > against counter wrap-around.
> > 
> > ...
> >
> >  include/linux/container.h |    8 +++
> >  kernel/container.c        |  116 +++++++++++++++++++++++++++++++++++++++++++--
> 
> gad, what's all this stuff?

The sound of me starting over.

> I think an IDR tree would get you what you're after in much less code. 

Ok, will look at that.  Thanks for the tip!

> Although it means that container IDs would get recycled quickly across a
> remove+add.
> 
> Be aware that there are IDR enhancements in Greg's driver tree (and hence
> in -mm) which are relevant to this application.
> 
> 
> > +	if (cont->auto_cnt_set) {
> 
> Can we please stop using "cnt" and "cont" to refer to containers?  Let's
> use "container", OK?

Ok.

thanks,
-serge