scsi: scsi_error: Handle power-on reset unit attention

As per SAM there is a status precedence, with any sense code 29/XX
taking second place just after an ACA ACTIVE status.  Additionally, each
target might prefer to not queue any unit attention conditions, but just
report one.  Due to the above, this will be that one with the highest
precedence.  This results in the sense code 29/XX effectively
overwriting any other unit attention.  Hence we should report the
power-on reset to userland so that it can take appropriate action.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_error.c

@@ -403,6 +403,12 @@ static void scsi_report_sense(struct scsi_device *sdev,
 				    "threshold.\n");
 		}
 
+		if (sshdr->asc == 0x29) {
+			evt_type = SDEV_EVT_POWER_ON_RESET_OCCURRED;
+			sdev_printk(KERN_WARNING, sdev,
+				    "Power-on or device reset occurred\n");
+		}
+
 		if (sshdr->asc == 0x2a && sshdr->ascq == 0x01) {
 			evt_type = SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED;
 			sdev_printk(KERN_WARNING, sdev,

drivers/scsi/scsi_lib.c

@@ -2743,6 +2743,9 @@ static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
 	case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
 		envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED";
 		break;
+	case SDEV_EVT_POWER_ON_RESET_OCCURRED:
+		envp[idx++] = "SDEV_UA=POWER_ON_RESET_OCCURRED";
+		break;
 	default:
 		/* do nothing */
 		break;
@@ -2847,6 +2850,7 @@ struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
 	case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
 	case SDEV_EVT_LUN_CHANGE_REPORTED:
 	case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
+	case SDEV_EVT_POWER_ON_RESET_OCCURRED:
 	default:
 		/* do nothing */
 		break;

include/scsi/scsi_device.h

@@ -64,9 +64,10 @@ enum scsi_device_event {
 	SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED,	/* 2A 01  UA reported */
 	SDEV_EVT_LUN_CHANGE_REPORTED,			/* 3F 0E  UA reported */
 	SDEV_EVT_ALUA_STATE_CHANGE_REPORTED,		/* 2A 06  UA reported */
+	SDEV_EVT_POWER_ON_RESET_OCCURRED,		/* 29 00  UA reported */
 
 	SDEV_EVT_FIRST		= SDEV_EVT_MEDIA_CHANGE,
-	SDEV_EVT_LAST		= SDEV_EVT_ALUA_STATE_CHANGE_REPORTED,
+	SDEV_EVT_LAST		= SDEV_EVT_POWER_ON_RESET_OCCURRED,
 
 	SDEV_EVT_MAXBITS	= SDEV_EVT_LAST + 1
 };