Using USB host in LPC1768

I am trying to implement USB host in LPC1768 and have written a code which initiliazes a mass storage device and creates a file in the same.Unfortunately,the code doesn't works and am not able to decode the issues with it.

#include <stdio.h>
#include "lpc17xx.h"
#include "rl_fs.h"

#include "cmsis_os.h"
#include "rl_usb.h"

#include "USBH_MSC.h"


int main (void)
{
usbStatus usb_status;
  int32_t   msc_status;
  FILE     *f;
  uint8_t   con = 0U;

usb_status = USBH_Initialize (0U);    // Initialize USB Host 0

        if (usb_status != usbOK) {
    for (;;) {
        LPC_GPIO2->FIOPIN=0XFFFFFFFF;
                }
 }

  for (;;) {

                msc_status = USBH_MSC_DriveGetMediaStatus ("U0:");
                LPC_GPIO2->FIOPIN=0XFFFFFFFF;
                if (msc_status == USBH_MSC_OK) {

                if (con == 0U) {
        con = 1U;

       msc_status = USBH_MSC_DriveMount ("U0:");
        if (msc_status != USBH_MSC_OK) {
          continue;
      }
        f = fopen ("Test.txt", "w");
       if (f == NULL) {
         continue;
        }
       fprintf (f, "USB Host Mass Storage!\n");
       fclose  (f);
        msc_status = USBH_MSC_DriveUnmount ("U0:");
        if (msc_status != USBH_MSC_OK) {
         continue;
        }
      }
    } else {
      if (con == 1U) {
        con = 0U;
    }
    osDelay(100U);
  }

 }