scsi: TUR path is down after adapter gets reset with multipath

This patch fixes an issue with multipath ipr SAS devices which require a
start unit command to be issued following an adapter reset. Without this
patch, paths get marked failed following an adapter reset and since the
error handler never gets invoked to issue the start unit, the paths are
never recovered. Returning FAILED for this case ensures the error
handler wakes up to issue the start unit.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Tested-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/device_handler/scsi_dh_alua.c

@@ -474,6 +474,13 @@ static int alua_check_sense(struct scsi_device *sdev,
 			 * LUN Not Ready -- Offline
 			 */
 			return SUCCESS;
+		if (sdev->allow_restart &&
+		    sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x02)
+			/*
+			 * if the device is not started, we need to wake
+			 * the error handler to start the motor
+			 */
+			return FAILED;
 		break;
 	case UNIT_ATTENTION:
 		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)