scsi: avoid ->change_queue_depth indirection for queue full tracking

All drivers use the implementation for ramping the queue up and down, so
instead of overloading the change_queue_depth method call the
implementation diretly if the driver opts into it by setting the
track_queue_depth flag in the host template.

Note that a few drivers validated the new queue depth in their
change_queue_depth method, but as we never go over the queue depth
set during slave_configure or the sysfs file this isn't nessecary
and can safely be removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Venkatesh Srinivas <venkateshs@google.com>

1 files changed, 2 insertions, 13 deletions

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 0ed96644ec94..670b75a62243 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -119,19 +119,7 @@ static int tcm_loop_change_queue_depth(
         int depth,
         int reason)
 {
-        switch (reason) {
-        case SCSI_QDEPTH_DEFAULT:
-                scsi_adjust_queue_depth(sdev, depth);
-                break;
-        case SCSI_QDEPTH_QFULL:
-                scsi_track_queue_full(sdev, depth);
-                break;
-        case SCSI_QDEPTH_RAMP_UP:
-                scsi_adjust_queue_depth(sdev, depth);
-                break;
-        default:
-                return -EOPNOTSUPP;
-        }
+        scsi_adjust_queue_depth(sdev, depth);
         return sdev->queue_depth;
 }
 
@@ -423,6 +411,7 @@ static struct scsi_host_template tcm_loop_driver_template = {
         .slave_alloc            = tcm_loop_slave_alloc,
         .module                 = THIS_MODULE,
         .use_blk_tags           = 1,
+        .track_queue_depth      = 1,
 };
 
 static int tcm_loop_driver_probe(struct device *dev)