Staging: hv: Enable blkvsc_ioctl()

We can support HDIO_GET_IDENTITY ioctl, enable blkvsc_ioctl().
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/blkvsc_drv.c

@@ -413,23 +413,18 @@ static void blkvsc_init_rw(struct blkvsc_request *blkvsc_req)
 
 
 static int blkvsc_ioctl(struct block_device *bd, fmode_t mode,
-			unsigned cmd, unsigned long argument)
+			unsigned cmd, unsigned long arg)
 {
-	int ret;
+	struct block_device_context *blkdev = bd->bd_disk->private_data;
+	int ret = 0;
 
 	switch (cmd) {
-	/*
-	 * TODO: I think there is certain format for HDIO_GET_IDENTITY rather
-	 * than just a GUID. Commented it out for now.
-	 */
-#if 0
 	case HDIO_GET_IDENTITY:
 		DPRINT_INFO(BLKVSC_DRV, "HDIO_GET_IDENTITY\n");
 		if (copy_to_user((void __user *)arg, blkdev->device_id,
 				 blkdev->device_id_len))
 			ret = -EFAULT;
 		break;
-#endif
 	default:
 		ret = -EINVAL;
 		break;