Re: [PATCH] scsi: Make scsi_vpd_lun_id() able to use T10 vendor ID based designators

[Hannes Reinecke <hare@suse.de>]

On 05/04/2016 08:58 AM, Paul Mackerras wrote:
> This adds code to scsi_vpd_lun_id() to enable it to use T10 vendor ID
> based designators.  This is needed to allow alua to work on disks that
> don't have any designators of type 2, 3 or 8.  Commit 0047220c6c36
> ("scsi_dh_alua: use unique device id", 2016-02-19) added a requirement
> that alua can only be used on disks for which scsi_vpd_lun_id() can
> produce an identifying string.
> 
> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
> ---
>  drivers/scsi/scsi_lib.c |   14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 8106515..f4f69cc 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -3214,6 +3214,20 @@ int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
>  			goto next_desig;
>  
>  		switch (d[1] & 0xf) {
> +		case 0x1:
> +			/* T10 vendor ID */
> +			if (cur_id_size > d[3])
> +				break;
> +			/* Prefer EUI-64 or NAA IEEE Registered Extended */
> +			if ((cur_id_type == 0x2 || cur_id_type == 0x3) &&
> +			    cur_id_size == d[3])
> +				break;
> +			cur_id_size = d[3];
> +			cur_id_str = d + 4;
> +			cur_id_type = d[1] & 0xf;
> +			id_size = snprintf(id, id_len, "%*phN", cur_id_size,
> +					   cur_id_str);
> +			break;
>  		case 0x2:
>  			/* EUI-64 */
>  			if (cur_id_size > d[3])
> 
Nearly.
The thing is, a T-10 vendor specific ID is _supposed_ to be an ASCII
string. So I'd rather have it decoded as such.
And we're missing decoding for 'vendor-specific' ID, too.

I'll be sending a replacement patch.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
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