Re: [Bug 80711] [PATCH]SG_FLAG_LUN_INHIBIT is no longer implemented and there's not way to prevent the kernel from using the 2nd cdb byte for the LUN

Alan Stern
2014-08-06T20:02:24Z

On Wed, 6 Aug 2014, Christoph Hellwig wrote:

> On Wed, Aug 06, 2014 at 03:29:47PM +0200, Douglas Gilbert wrote:
> > If not and since I'm told black lists and the like won't
> > work, my advice for the record is to use FreeBSD or Windows
> > for tools that need this capability.
>
> I doubt either of them forces users to hack up flags for these cases.

Why was this change needed in the first place? There's no explanation
in the patch itself.

> At least for windows I suspect it just never sends the LUN encoded
> in the CDB and treats USB devices special instead of our insistance
> on pretending they are SCSI-2.

We no longer pretend that USB mass-storage devices have any particular
SCSI level. See commit 09b6b51b0b6c.

> Maybe some of the USB people have on the wire traces or access to
> device or windows documentation on this?

Most likely it varies with the version of Windows and the INQUIRY data
returned by the device.

I can obtain hardware traces for the kinds of devices and computers
lying around here. But what sort of combinations should I test?

Alan Stern