Re: [PATCH 1/2] Use sdev_scsi2lun for SCSI parallel drivers

Hannes Reinecke
2014-07-07T07:54:53Z

On 07/05/2014 11:41 AM, Christoph Hellwig wrote:
> On Fri, Jul 04, 2014 at 04:12:22PM +0200, Hannes Reinecke wrote:
>>> So what would be set in the upper 48 bits for those drivers? We receive
>>> the LUN over the wire to start with.
>>>
>> None. All these devices are physically incapable of receiving or sending
>> LUNs more that a byte wide.
>
> So what problems does this patch fix then?
>
The intention is twofold:

1) Isolate from any fallout due to the 64bit LUN changes. By
introducing accessors we are guaranteed that the drivers will only
ever see LUN numbers they are expecting.
2) Using accessors allows us to eventually change the ->lun field to
'struct scsi_lun', and call 'scsilun_to_int' only for display
purposes. This will address the objection by Bart for
ib_srp, but applies to other drivers as well.

Cheers,

Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@suse.de +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html