[disco:linux-azure][PATCH 1/1] scsi: storvsc: Add ability to change scsi queue depth

[Marcelo Henrique Cerri]

From: Branden Bonaby <brandonbonaby94 at gmail.com>

BugLink: https://bugs.launchpad.net/bugs/1849495

Adding functionality to allow the SCSI queue depth to be changed by
utilizing the "scsi_change_queue_depth" function.

[mkp: checkpatch]

Signed-off-by: Branden Bonaby <brandonbonaby94 at gmail.com>
Reviewed-by: Michael Kelley <mikelley at microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys at microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
(cherry picked from commit adfbd028e155fca3bbe33d458f2f27cb657e5792)
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri at canonical.com>
---
 drivers/scsi/storvsc_drv.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 3a7278306d4f..d7033ece5459 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -387,6 +387,7 @@ enum storvsc_request_type {
 
 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
 static u32 max_outstanding_req_per_channel;
+static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 
 static int storvsc_vcpus_per_sub_channel = 4;
 
@@ -1711,6 +1712,7 @@ static struct scsi_host_template scsi_driver = {
 	.dma_boundary =		PAGE_SIZE-1,
 	.no_write_same =	1,
 	.track_queue_depth =	1,
+	.change_queue_depth =	storvsc_change_queue_depth,
 };
 
 enum {
@@ -1923,6 +1925,15 @@ static int storvsc_probe(struct hv_device *device,
 	return ret;
 }
 
+/* Change a scsi target's queue depth */
+static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
+{
+	if (queue_depth > scsi_driver.can_queue)
+		queue_depth = scsi_driver.can_queue;
+
+	return scsi_change_queue_depth(sdev, queue_depth);
+}
+
 static int storvsc_remove(struct hv_device *dev)
 {
 	struct storvsc_device *stor_device = hv_get_drvdata(dev);
-- 
2.20.1