[PATCH v4 16/40] scsi: device_handlers: alua: use 16-bits defined sense codes

[Damien Le Moal <dlemoal@kernel.org>]

Refactor the SCSI ALUA devie handler driver to use the 16-bits sense_code
field of struct scsi_sense_hdr and replace all hard-coded additional sense
codes and additional sense code qualifiers with the enum values defined in
include/scsi/scsi_sense.h. This helps with code clarity as the sense codes
being processed are easier to test and self-documented.

No functional change intended.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
---
 drivers/scsi/device_handler/scsi_dh_alua.c | 55 ++++++++--------------
 1 file changed, 19 insertions(+), 36 deletions(-)

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index d81ec47a7140..87ac0a6d63e5 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -433,61 +433,43 @@ static enum scsi_disposition alua_check_sense(struct scsi_device *sdev,
 {
 	switch (sense_hdr->sense_key) {
 	case NOT_READY:
-		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) {
-			/*
-			 * LUN Not Accessible - ALUA state transition
-			 */
+		if (sense_hdr->sense_code ==
+		    LU_NOT_ACCESSIBLE_ASYMMETRIC_ACCESS_STATE_TRANSITION) {
 			alua_handle_state_transition(sdev);
 			return NEEDS_RETRY;
 		}
 		break;
 	case UNIT_ATTENTION:
-		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) {
-			/*
-			 * LUN Not Accessible - ALUA state transition
-			 */
+		if (sense_hdr->sense_code ==
+		    LU_NOT_ACCESSIBLE_ASYMMETRIC_ACCESS_STATE_TRANSITION) {
 			alua_handle_state_transition(sdev);
 			return NEEDS_RETRY;
 		}
-		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) {
+		if (sense_hdr->sense_code ==
+		    POWER_ON_RESET_OR_BUS_DEVICE_RESET_OCCURRED) {
 			/*
-			 * Power On, Reset, or Bus Device Reset.
 			 * Might have obscured a state transition,
 			 * so schedule a recheck.
 			 */
 			alua_check(sdev, true);
 			return ADD_TO_MLQUEUE;
 		}
-		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04)
-			/*
-			 * Device internal reset
-			 */
+		if (sense_hdr->sense_code == DEVICE_INTERNAL_RESET)
 			return ADD_TO_MLQUEUE;
-		if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01)
-			/*
-			 * Mode Parameters Changed
-			 */
+		if (sense_hdr->sense_code == MODE_PARAMETERS_CHANGED)
 			return ADD_TO_MLQUEUE;
-		if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) {
-			/*
-			 * ALUA state changed
-			 */
+		if (sense_hdr->sense_code == ASYMMETRIC_ACCESS_STATE_CHANGED) {
 			alua_check(sdev, true);
 			return ADD_TO_MLQUEUE;
 		}
-		if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) {
-			/*
-			 * Implicit ALUA state transition failed
-			 */
+		if (sense_hdr->sense_code ==
+		    IMPLICIT_ASYMMETRIC_ACCESS_STATE_TRANSITION_FAILED) {
 			alua_check(sdev, true);
 			return ADD_TO_MLQUEUE;
 		}
-		if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03)
-			/*
-			 * Inquiry data has changed
-			 */
+		if (sense_hdr->sense_code == INQUIRY_DATA_HAS_CHANGED)
 			return ADD_TO_MLQUEUE;
-		if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e)
+		if (sense_hdr->sense_code == REPORTED_LUNS_DATA_HAS_CHANGED)
 			/*
 			 * REPORTED_LUNS_DATA_HAS_CHANGED is reported
 			 * when switching controllers on targets like
@@ -517,12 +499,12 @@ static int alua_tur(struct scsi_device *sdev)
 				      ALUA_FAILOVER_RETRIES, &sense_hdr);
 	if ((sense_hdr.sense_key == NOT_READY ||
 	     sense_hdr.sense_key == UNIT_ATTENTION) &&
-	    sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a)
+	    sense_hdr.sense_code ==
+	    LU_NOT_ACCESSIBLE_ASYMMETRIC_ACCESS_STATE_TRANSITION)
 		return SCSI_DH_RETRY;
-	else if (retval)
+	if (retval)
 		return SCSI_DH_IO;
-	else
-		return SCSI_DH_OK;
+	return SCSI_DH_OK;
 }
 
 /*
@@ -619,7 +601,8 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
 		 * transition. So set the state to 'transitioning' directly.
 		 */
 		if (sense_hdr.sense_key == NOT_READY &&
-		    sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) {
+		    sense_hdr.sense_code ==
+		    LU_NOT_ACCESSIBLE_ASYMMETRIC_ACCESS_STATE_TRANSITION) {
 			transitioning_sense = true;
 			goto skip_rtpg;
 		}
-- 
2.55.0