[PATCH 00/40] Staging: hv: Driver cleanup

[Stephen Hemminger]

On Thu, 30 Jun 2011 23:32:34 +0000
KY Srinivasan <kys at microsoft.com> wrote:

> 
> > -----Original Message-----
> > From: Christoph Hellwig [mailto:hch at infradead.org]
> > Sent: Thursday, June 30, 2011 3:34 PM
> > To: KY Srinivasan
> > Cc: gregkh at suse.de; linux-kernel at vger.kernel.org;
> > devel at linuxdriverproject.org; virtualization at lists.osdl.org
> > Subject: Re: [PATCH 00/40] Staging: hv: Driver cleanup
> > 
> > On Wed, Jun 29, 2011 at 07:38:21AM -0700, K. Y. Srinivasan wrote:
> > > Further cleanup of the hv drivers:
> > >
> > > 	1) Cleanup the reference counting mess for both stor and net devices.
> > 
> > I really don't understand the need for reference counting on the storage
> > side, especially now that you only have a SCSI driver.  The SCSI
> > midlayer does proper counting on it's objects (Scsi_Host, scsi_device,
> > scsi_cmnd), so you'll get that for free given that SCSI drivers just
> > piggyback on the midlayer lifetime rules.
> > 
> > For now your patches should probably go in as-is, but mid-term you
> > should be able to completely remove that code on the storage side.
> > 
> 
> Greg,
> 
> I am thinking of  going back to my original implementation where I had one scsi host
> per IDE device. This will certainly simply the code. Let me know what you think. If you
> agree with this approach, please drop this patch-set, I will send you a new set of patches.

I think there ref counting on network devices is also unneeded
as long as the unregister logic handles RCU correctly. The network layer
calls the driver unregister routine after all packets are gone.