Win32 Windows Volume Program and Code Example 3

 

 

 

 

 

Obtaining File System Recognition Information Example

 

File system recognition is the ability to recognize storage media that contain a valid file system/volume layout that hasn’t been defined yet, but the media is able to identify itself through the presence of the recognition structure defined internally by Windows. Because no existing file system will recognize a new disk layout, the "RAW" file system will mount the volume and provide direct block level access. The "RAW" file system, incorporated in ntoskrnl, will have the ability to read the file system recognition structure and provide applications access to such structures through the file system control request FSCTL_QUERY_FILE_SYSTEM_RECOGNITION, shown in the following code snippet.

Create a new Win32 console application project and give a suitable project name.

 

Obtaining File System Recognition Information Example - creating a new win32 project

 

Add the source file and give a suitable name.

 

Obtaining File System Recognition Information Example - adding a new C++ source file

 

Add the following source code.

 

#include <windows.h>

#include <stdio.h>

#include <wchar.h>

// Min client - Windows 7;

// Min server - Windows Server 2008 R2

#include <Winioctl.h>

 

typedef struct _FILE_SYSTEM_RECOGNITION_INFORMATION {

  CHAR FileSystem[9];

}FILE_SYSTEM_RECOGNITION_INFORMATION, *PFILE_SYSTEM_RECOGNITION_INFORMATION;

 

STDMETHODIMP Check(PCWSTR  pcwszDrive)

{

    HRESULT                                 hr = S_OK;

    HANDLE                                  hDisk = INVALID_HANDLE_VALUE;

    FILE_SYSTEM_RECOGNITION_INFORMATION     FsRi = {0};

      DWORD dwIoControlCode = 0;

    BOOL                                    fResult = FALSE;   

    ULONG                                   BytesReturned = 0;   

   

    // Open the target, for example "\\.\F:"

    wprintf(L"CreateFile() on %s...\n", pcwszDrive);

    hDisk = CreateFile(pcwszDrive,

                        FILE_READ_ATTRIBUTES|SYNCHRONIZE|FILE_TRAVERSE,                       

                        FILE_SHARE_READ|FILE_SHARE_WRITE,

                        NULL, OPEN_EXISTING, 0, NULL);   

    if(hDisk == INVALID_HANDLE_VALUE)

    {

        hr = GetLastError();

        wprintf(L"CreateFile() failed on %s, error = %u\n", pcwszDrive, GetLastError());

        exit(1);

    }

 

    wprintf(L"CreateFile() succeeded.\n");

    wprintf(L"\nPress Any Key to send down the FSCTL...\n");

    _getwch();

 

    // Send down the FSCTL

    wprintf( L"Calling DeviceIoControl(...,FSCTL_QUERY_FILE_SYSTEM_RECOGNITION,...)\n" );

    // http://msdn.microsoft.com/en-us/library/aa365729%28VS.85%29.aspx

    // and another one: http://msdn.microsoft.com/en-us/library/cc232013%28PROT.10%29.aspx

    fResult = DeviceIoControl(hDisk, FSCTL_QUERY_FILE_SYSTEM_RECOGNITION, NULL, 0,

            &FsRi, sizeof(FsRi), &BytesReturned, NULL );

    if(!fResult)

    {

        hr = HRESULT_FROM_WIN32(GetLastError());

        wprintf(L"DeviceIoControl() failed, error %u\n", GetLastError());

        exit(1);

    }

 

    wprintf(L"DeviceIoControl() succeeded.\n");

    wprintf(L"FSCTL_QUERY_FILE_SYSTEM_RECOGNITION returned success.\n");

    wprintf(L"FSCTL_QUERY_FILE_SYSTEM_RECOGNITION thinks the filesystem is \"%s\".\n", FsRi.FileSystem);

 

    if(hDisk != INVALID_HANDLE_VALUE)

    {

        CloseHandle(hDisk);

        hDisk = INVALID_HANDLE_VALUE;

    }

 

    return hr;

}

 

int wmain(int argc, WCHAR **argv)

{

      Check(L"\\\\.\\C:");

      return 0;

}

 

Take note that the FSCTL_QUERY_FILE_SYSTEM_RECOGNITION cannot be found in the Winioctl.h header file at the moment this program example was tested. It is intended for vendors and the minimum system to run this program is Windows 7/Server 2008 R2.

 

 

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