[SCSI] libosd: OSD2r05: on-the-wire changes for latest OSD2 revision 5.

OSC's OSD2 target: [git clone git://git.open-osd.org/osc-osd/ master]
(Initiator code prior to this patch must use: "git checkout CDB_VER_OSD2r01"
 in the target tree above)

This is a summery of the wire changes:

 * OSDv2_ADDITIONAL_CDB_LENGTH == 192 => 228 (Total CDB is now 236 bytes)
 * Attributes List Element Header grew, so attribute values are 8 bytes
   aligned.
 * Cryptographic keys and signatures are 20 => 32
 * Few new definitions.

(Still missing new standard definitions attribute values, these do not change
 wire format and will be added later when needed)

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/osd/osd_initiator.c

@@ -263,7 +263,12 @@ static int _osd_req_alist_elem_decode(struct osd_request *or,
 		oa->attr_page = be32_to_cpu(attr->attr_page);
 		oa->attr_id = be32_to_cpu(attr->attr_id);
 
-		oa->val_ptr = attr->attr_val;
+		/* OSD2: For convenience, on empty attributes, we return 8 bytes
+		 * of zeros here. This keeps the same behaviour with OSD2r04,
+		 * and is nice with null terminating ASCII fields.
+		 * oa->val_ptr == NULL marks the end-of-list, or error.
+		 */
+		oa->val_ptr = likely(oa->len) ? attr->attr_val : attr->reserved;
 	}
 	return inc;
 }