大家好，
我写了个usb的测试程序，目的是进行以下一些测试，attach/detach, mount/unmount, opendir/readdir/closedir, open file/read file/close file. 运行程序可以检测到 attach/detach, 但是mount失败。想请教一下问题出在哪里，怎么改正，谢谢各位。附上代码。
/*........................... FILE PROLOGUE ..........................*/
/*
.FP
***********************************************************************
*
* FILE NAME:
* usb_test_case.c
*
* PURPOSE:
* This file is used to verify that the API calls used to access and control the USB drive.
* DLE can use to determine when the USB drive has been detached during use.
***********************************************************************
.FP END
*/
/* ------------------------------ FILE INCLUSION ----------------------------*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h> /* Standard types */
#include <stdint.h> /* for integer types*/
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sched.h>
#include <fcntl.h>
#include <sys/file.h>
#include <time.h>
#include <usb.h>
#include <unistd.h>
#include <dirent.h>
#include <io.h>
#include <unistd.h>
#include <errno.h>
static char* blocknode = "/dev/ddev/sdusb";
static char* charnode = "/dev/ddev/usb.ctrl";
static char* mountpoint_1 = "/tmp/tftproot";
static char* mountpoint = "/tmp/tftproot/usb";
static int fh1;
static unsigned int bytesread;
void wait_for_event(int read_fd);
void walk_dir(const char *file);
void access_read(const char *file);
void open_file(void);
void read_file(void);
void close_file(void);
#define SCSI_DRIVER_MOUNT 1
#define SUC 0
#define ERR 1
/*
*******************************************************************************
-*
-* NAME:
-* wait_for_event
-*
-* PURPOSE:
-* This function is used to discover if any changes has happened on the USB port
-* or not and read the events generated by USB driver.
-*
-* PARAMETERS:
-*
-* INPUT: int read_fd - USB character device file handle
-*
-* OUTPUT: None
-*
-* RETURNS: None
-*
-* NOTES: None
-*
*******************************************************************************
*/
void wait_for_event(int read_fd)
{
usb_event *event = NULL;