scsi: always assign block layer tags if enabled

Allow a driver to ask for block layer tags by setting .use_blk_tags in the
host template, in which case it will always see a valid value in
request->tag, similar to the behavior when using blk-mq.  This means even
SCSI "untagged" commands will now have a tag, which is especially useful
when using a host-wide tag map.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index a964f8c..4723d89 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -2888,11 +2888,11 @@
 	if (sdev->type == TYPE_DISK)
 		sdev->allow_restart = 1;
 
-	if (sdev->tagged_supported) {
-		scsi_set_tag_type(sdev, MSG_SIMPLE_TAG);
-		scsi_activate_tcq(sdev, sdev->queue_depth);
-	} else
-		scsi_deactivate_tcq(sdev, sdev->queue_depth);
+	if (sdev->tagged_supported)
+		scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG,
+				sdev->queue_depth);
+	else
+		scsi_adjust_queue_depth(sdev, 0, sdev->queue_depth);
 	spin_unlock_irqrestore(shost->host_lock, flags);
 	return 0;
 }
@@ -3108,6 +3108,7 @@
 	.max_sectors = IBMVFC_MAX_SECTORS,
 	.use_clustering = ENABLE_CLUSTERING,
 	.shost_attrs = ibmvfc_attrs,
+	.use_blk_tags = 1,
 };
 
 /**