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

commit adb6f9e1 upstream.

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>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/scsi/storvsc_drv.c

@@ -1764,19 +1764,22 @@ 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);