Windows IOCTL 获取 Volume 信息 (FSCTL_GET_NTFS_VOLUME_DATA)

#define UNICODE 1
#define _UNICODE 1

/* The code of interest is in the subroutine GetDriveGeometry. The
code in main shows how to interpret the results of the call. */

#include <windows.h>
#include <winioctl.h>
#include <stdio.h>

#define wszDrive L"\\.\PhysicalDrive0"

//#define wszVol L"\\?\Volume{32ef8775-ad83-45dd-9617-312e4c36f1ca}"
#define wszVol L"\\.\M:"
//#define wszVol L"\\?\Volume{fd47549e-0000-0000-0000-402400000000}"

BOOL GetVolInfo(LPWSTR wszPath, NTFS_VOLUME_DATA_BUFFER *pdg)
{
    HANDLE hDevice = INVALID_HANDLE_VALUE;  // handle to the drive to be examined 
    BOOL bResult = FALSE;                 // results flag
    DWORD bytesReturned = 0;                     // discard results

    hDevice = CreateFileW(wszPath,
        FILE_EXECUTE,
        FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
        NULL,             // default security attributes
        OPEN_EXISTING,    // disposition
        FILE_ATTRIBUTE_NORMAL,                // file attributes
        NULL);            // do not copy file attributes

    if (hDevice == INVALID_HANDLE_VALUE)    // cannot open the drive
    {
        printf("Failed to open vol %ls
", wszPath);
        return (FALSE);
    }

    bResult = DeviceIoControl(hDevice,                       // device to be queried
        FSCTL_GET_NTFS_VOLUME_DATA, // operation to perform
        NULL, 0,                       // no input buffer
        (LPVOID)pdg, sizeof(*pdg),            // output buffer
        &bytesReturned,                         // # bytes returned
        (LPOVERLAPPED)NULL);          // synchronous I/O

    CloseHandle(hDevice);

    printf("FSCTL_GET_NTFS_VOLUME_DATA bytesReturned %ld
",
        bytesReturned);

    return (bResult);
}

int wmain(int argc, wchar_t *argv[])
{
    NTFS_VOLUME_DATA_BUFFER pdg = { 0 }; // disk drive geometry structure
    BOOL bResult = FALSE;      // generic results flag
    ULONGLONG DiskSize = 0;    // size of the drive, in bytes

    bResult = GetVolInfo(wszVol, &pdg);

    if (bResult)
    {
        wprintf(L"Volume path      = %ws
", wszVol);
        wprintf(L"BytesPerCluster  = %ld
", pdg.BytesPerCluster);
    }
    else
    {
        wprintf(L"GetVolInfo %ls failed. Error %ld.
", wszVol, GetLastError());
    }

    return ((int)bResult);
}