Re: [RFC PATCH] Introduce filesystem type tracking

[Christian Brauner]

On Tue, May 20, 2008 at 09:57:32AM -0400, Christoph Hellwig wrote:
> On Tue, May 20, 2008 at 02:43:06PM +0100, Al Viro wrote:
> > No, you have not and no, doing that anywhere near that layer is hopeless.
> > 
> > 	a) Instances of filesystem can easily outlive all vfsmounts,
> > let alone their attachment to namespaces.
> > 	b) What should happen if init is done in the middle of exit?
> > 	c) Why do we need to bother, anyway?  
> 
> We had a discussion about filesystems starting threads without an
> active instance.  I suggested tracking instances and add ->init / ->exit
> methods to struct file_system_type for these kinds of instances.

I'm sorry but the infrastructure patches that are advocated here for
this are terrible. I'm really not convinced at all that this is
something we are going to support. We definitely don't need additional
sleeping locks for this in the code.