Re: [PATCH 1/4] stex: fix id mapping issue(v3)

[James Bottomley <James.Bottomley@SteelEye.com>]

On Thu, 2007-04-05 at 08:42 +0100, Christoph Hellwig wrote:
> On Wed, Apr 04, 2007 at 08:05:59PM -0500, James Bottomley wrote:
> > Erm, there's a simple way out of this:  That's the BLIST_FORCELUN
> > option.  This is why most of the RAID devices have entries in
> > scsi_devinfo.c like:
> > 
> >         {"ADAPTEC", "AACRAID", NULL, BLIST_FORCELUN},
> > 
> > Which overrides the CONFIG_SCSI_MULTI_LUN setting for the particular
> > device.  We can easily add an entry for stex as well.
> 
> IMHO we should kill CONFIG_SCSI_MULTI_LUN and add blacklist enries for
> devices that don't handle scanning for luns > 1 instead.  I think the
> RH/Fedora kernel has started collecting these blacklist entries for
> a long time already.

I wouldn't disagree with that.  There have been several schools of
thought on this:  One was that every multi-lun device since SPC should
support REPORT LUNS, so MULTI_LUN should be off by default and we
whitelist non SPC compliant multi-lun devices.  If we also added a host
hook to allow RAID devices to declare themselves, then I think we
capture 99% of the current cases.

Another is just to make it on by default.  I note that both SLES10 and
RHEL5 now define it on, so I can't see much argument in support of a
distro setting it off.

James