Drivers: scsi: storvsc: Fix a bug in handling VMBUS protocol version

Based on the negotiated VMBUS protocol version, we adjust the size of the storage
protocol messages. The two sizes we currently handle are pre-win8 and post-win8.
In WS2012 R2, we are negotiating higher VMBUS protocol version than the win8
version. Make adjustments to correctly handle this.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/storvsc_drv.c

@@ -1752,19 +1752,22 @@ static int storvsc_probe(struct hv_device *device,
 	 * set state to properly communicate with the host.
 	 */
 
-	if (vmbus_proto_version == VERSION_WIN8) {
-		sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
-		vmscsi_size_delta = 0;
-		vmstor_current_major = VMSTOR_WIN8_MAJOR;
-		vmstor_current_minor = VMSTOR_WIN8_MINOR;
-	} else {
+	switch (vmbus_proto_version) {
+	case VERSION_WS2008:
+	case VERSION_WIN7:
 		sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 		vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 		vmstor_current_major = VMSTOR_WIN7_MAJOR;
 		vmstor_current_minor = VMSTOR_WIN7_MINOR;
+		break;
+	default:
+		sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
+		vmscsi_size_delta = 0;
+		vmstor_current_major = VMSTOR_WIN8_MAJOR;
+		vmstor_current_minor = VMSTOR_WIN8_MINOR;
+		break;
 	}
 
-
 	if (dev_id->driver_data == SFC_GUID)
 		scsi_driver.can_queue = (STORVSC_MAX_IO_REQUESTS *
 					 STORVSC_FC_MAX_TARGETS);