Re: [PATCH 1/2] Improve SCSI device type decoding

[Douglas Gilbert <dougg@torque.net>]

Matthew Wilcox wrote:
> On Wed, Jun 21, 2006 at 02:02:35PM -0400, Douglas Gilbert wrote:
> 
>>Not forgetting peripheral device types 1eh and 1fh
>>which are well known logical unit and unknown or
>>no device type respectively.
> 
> 
> I don't think you read the whole patch ;-)

Obviously not closely enough.

> +       if (type == 0x1e)
> +               return "Well-known LUN   ";
> +       if (type > ARRAY_SIZE(scsi_device_types))
> +               return "Unknown          ";
> 
> Did you want to distinguish between a device of type unknown and a
> device type Linux doesn't know about?

If a device server yields a peripheral qualifier of 3
in a INQUIRY response (e.g. for the "lun 0" trick when
there are lun_s>0) then the associated pdt should be
set to 1fh. The unallocated pdt_s are marked as "reserved"
in the draft.
It is also possible that a drive with removable media
may not want to commit to a pdt before it sees media.
So I would prefer to see the distinction.


Doug Gilbert