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>

1 files changed, 10 insertions, 7 deletions

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 8f8847ef1108..7e8a64251681 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/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);