[PATCH 1/1] scsi: storvsc: Log TEST_UNIT_READY errors as warnings

[Michael Kelley <mikelley@microsoft.com>]

Commit 08f76547f08d ("scsi: storvsc: Update error logging")
added more robust logging of errors, particularly those reported
as Hyper-V errors. But this change produces extra logging noise
in that TEST_UNIT_READY may report errors during the normal
course of detecting device adds and removes.

Fix this by logging TEST_UNIT_READY errors as warnings, so that
log lines are produced only if the storvsc log level is changed
to WARN level on the kernel boot line.

Fixes: 08f76547f08d ("scsi: storvsc: Update error logging")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---
 drivers/scsi/storvsc_drv.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 328bb96..37506b3 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1199,14 +1199,24 @@ static void storvsc_on_io_completion(struct storvsc_device *stor_device,
 		vstor_packet->vm_srb.sense_info_length);
 
 	if (vstor_packet->vm_srb.scsi_status != 0 ||
-	    vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
-		storvsc_log(device, STORVSC_LOGGING_ERROR,
+	    vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS) {
+
+		/*
+		 * Log TEST_UNIT_READY errors only as warnings. Hyper-V can
+		 * return errors when detecting devices using TEST_UNIT_READY,
+		 * and logging these as errors produces unhelpful noise.
+		 */
+		int loglevel = (stor_pkt->vm_srb.cdb[0] == TEST_UNIT_READY) ?
+			STORVSC_LOGGING_WARN : STORVSC_LOGGING_ERROR;
+
+		storvsc_log(device, loglevel,
 			"tag#%d cmd 0x%x status: scsi 0x%x srb 0x%x hv 0x%x\n",
 			request->cmd->request->tag,
 			stor_pkt->vm_srb.cdb[0],
 			vstor_packet->vm_srb.scsi_status,
 			vstor_packet->vm_srb.srb_status,
 			vstor_packet->status);
+	}
 
 	if (vstor_packet->vm_srb.scsi_status == SAM_STAT_CHECK_CONDITION &&
 	    (vstor_packet->vm_srb.srb_status & SRB_STATUS_AUTOSENSE_VALID))
-- 
1.8.3.1