On Wed, May 04, 2016 at 12:04:16PM +0200, Hannes Reinecke wrote:
> 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 <[email protected]>
> > ---
> > 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.
Do we need to defend against non-printing characters in the string?
> And we're missing decoding for 'vendor-specific' ID, too.
There's no guarantee that this would be ASCII, right? So would you
print it in hex?
Also, is there a preference between these types? For example, is an
8-byte EUI-64 preferable to a vendor-specific ID of any length?
Cheers,
Paul.
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