[PATCH 2/2] scsi: target: Add the VERSION DESCRIPTOR fields to the INQUIRY data

[Konstantin Shelekhin <k.shelekhin@yadro.com>]

Extend the standard INQUIRY data to 96 bytes and fill in the VERSION
DESCRIPTOR fields.

The layout follows SPC-4:

  SCSI architecture standard
  SCSI transport protocol standard
  SCSI primary command set standard
  SCSI device type command set standard

All version descriptor values are defined as "unclaimed" because some
initiators fail to recognize anything else.

Signed-off-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
---
 drivers/target/target_core_spc.c | 34 +++++++++++++++++++++++++++++++-
 include/scsi/scsi_proto.h        | 12 +++++++++++
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index c42a954ce641..d3b2f3d075bf 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -47,10 +47,32 @@ static void spc_fill_alua_data(struct se_lun *lun, unsigned char *buf)
 	spin_unlock(&lun->lun_tg_pt_gp_lock);
 }
 
+static u16
+spc_find_scsi_transport_vd(int proto_id)
+{
+	switch (proto_id) {
+	case SCSI_PROTOCOL_FCP:
+		return SCSI_VERSION_DESCRIPTOR_FCP4;
+	case SCSI_PROTOCOL_ISCSI:
+		return SCSI_VERSION_DESCRIPTOR_ISCSI;
+	case SCSI_PROTOCOL_SAS:
+		return SCSI_VERSION_DESCRIPTOR_SAS3;
+	case SCSI_PROTOCOL_SBP:
+		return SCSI_VERSION_DESCRIPTOR_SBP3;
+	case SCSI_PROTOCOL_SRP:
+		return SCSI_VERSION_DESCRIPTOR_SRP;
+	default:
+		pr_warn("Cannot find VERSION DESCRIPTOR value for unknown SCSI"
+		        " transport PROTOCOL IDENTIFIER %#x\n", proto_id);
+		return 0;
+	}
+}
+
 sense_reason_t
 spc_emulate_inquiry_std(struct se_cmd *cmd, unsigned char *buf)
 {
 	struct se_lun *lun = cmd->se_lun;
+	struct se_portal_group *tpg = lun->lun_tpg;
 	struct se_device *dev = cmd->se_dev;
 	struct se_session *sess = cmd->se_sess;
 
@@ -108,7 +130,17 @@ spc_emulate_inquiry_std(struct se_cmd *cmd, unsigned char *buf)
 	       strnlen(dev->t10_wwn.model, INQUIRY_MODEL_LEN));
 	memcpy(&buf[32], dev->t10_wwn.revision,
 	       strnlen(dev->t10_wwn.revision, INQUIRY_REVISION_LEN));
-	buf[4] = 31; /* Set additional length to 31 */
+
+	/*
+	 * Set the VERSION DESCRIPTOR fields
+	 */
+	put_unaligned_be16(SCSI_VERSION_DESCRIPTOR_SAM5, &buf[58]);
+	put_unaligned_be16(spc_find_scsi_transport_vd(tpg->proto_id), &buf[60]);
+	put_unaligned_be16(SCSI_VERSION_DESCRIPTOR_SPC4, &buf[62]);
+	if (cmd->se_dev->transport->get_device_type(dev) == TYPE_DISK)
+		put_unaligned_be16(SCSI_VERSION_DESCRIPTOR_SBC3, &buf[64]);
+
+	buf[4] = 91; /* Set additional length to 91 */
 
 	return 0;
 }
diff --git a/include/scsi/scsi_proto.h b/include/scsi/scsi_proto.h
index c36860111932..5c106c4f249e 100644
--- a/include/scsi/scsi_proto.h
+++ b/include/scsi/scsi_proto.h
@@ -341,4 +341,16 @@ enum zbc_zone_cond {
 	ZBC_ZONE_COND_OFFLINE		= 0xf,
 };
 
+/* Version descriptor values for INQUIRY */
+enum scsi_version_descriptor {
+	SCSI_VERSION_DESCRIPTOR_FCP4	= 0x0a40,
+	SCSI_VERSION_DESCRIPTOR_ISCSI	= 0x0960,
+	SCSI_VERSION_DESCRIPTOR_SAM5	= 0x00a0,
+	SCSI_VERSION_DESCRIPTOR_SAS3	= 0x0c60,
+	SCSI_VERSION_DESCRIPTOR_SBC3	= 0x04c0,
+	SCSI_VERSION_DESCRIPTOR_SBP3	= 0x0980,
+	SCSI_VERSION_DESCRIPTOR_SPC4	= 0x0460,
+	SCSI_VERSION_DESCRIPTOR_SRP	= 0x0940
+};
+
 #endif /* _SCSI_PROTO_H_ */
-- 
2.31.1