[pnfs] [PATCH 05/28] pnfsblock: expose scsi interface

[Christoph Hellwig]

On Wed, Mar 12, 2008 at 06:33:34PM +0200, Benny Halevy wrote:
> This calls for a layering violation.
> 
> To fill-in more context, here's an excerpt from the next patch,
> showing how you use shost_class to scan all scsi disks:

Yes, absolutely.  No one outside of few places in the core scsi code
should ever iterate over the scsi disks.

> My question is how should a proper API between the scsi layer and
> the block layout driver look like?
> 
> Can you list your requirements, e.g.:
> - scanning all available devices,
> 
> - discovering new devices on the fly
> 
> - getting notified for new devices?

Neither.  pnfs shouldn't open block devices from kernelspace at all,
but do it's disovery in userspace.

Or even better this whole block layout driver crap should go away
completely and the people who have designed it beaten up until they
aren't recognizable anymore.