3 files changed, 24 insertions, 6 deletions
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index d81f3cc43ff1..1423cb17fbfd 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -670,14 +670,10 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 		return SCSI_MLQUEUE_DEVICE_BUSY;
 	}
 
-	/*
-	 * If SCSI-2 or lower, store the LUN value in cmnd.
-	 */
-	if (cmd->device->scsi_level <= SCSI_2 &&
-	    cmd->device->scsi_level != SCSI_UNKNOWN) {
+	/* Store the LUN value in cmnd, if needed. */
+	if (cmd->device->lun_in_cdb)
 		cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
 			       (cmd->device->lun << 5 & 0xe0);
-	}
 
 	scsi_log_send(cmd);
 
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 56675dbbf681..f84c40188478 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -736,6 +736,16 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
 		sdev->scsi_level++;
 	sdev->sdev_target->scsi_level = sdev->scsi_level;
 
+	/*
+	 * If SCSI-2 or lower, and if the transport requires it,
+	 * store the LUN value in CDB[1].
+	 */
+	sdev->lun_in_cdb = 0;
+	if (sdev->scsi_level <= SCSI_2 &&
+	    sdev->scsi_level != SCSI_UNKNOWN &&
+	    !sdev->host->no_scsi2_lun_in_cdb)
+		sdev->lun_in_cdb = 1;
+
 	return 0;
 }
 
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 8b4105a22ac2..85e36f3a5585 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1263,7 +1263,19 @@ void scsi_sysfs_device_initialize(struct scsi_device *sdev)
 	sdev->sdev_dev.class = &sdev_class;
 	dev_set_name(&sdev->sdev_dev, "%d:%d:%d:%llu",
 		     sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
+	/*
+	 * Get a default scsi_level from the target (derived from sibling
+	 * devices).  This is the best we can do for guessing how to set
+	 * sdev->lun_in_cdb for the initial INQUIRY command.  For LUN 0 the
+	 * setting doesn't matter, because all the bits are zero anyway.
+	 * But it does matter for higher LUNs.
+	 */
 	sdev->scsi_level = starget->scsi_level;
+	if (sdev->scsi_level <= SCSI_2 &&
+			sdev->scsi_level != SCSI_UNKNOWN &&
+			!shost->no_scsi2_lun_in_cdb)
+		sdev->lun_in_cdb = 1;
+
 	transport_setup_device(&sdev->sdev_gendev);
 	spin_lock_irqsave(shost->host_lock, flags);
 	list_add_tail(&sdev->same_target_siblings, &starget->devices);