cdfs_rec.c

微软win2k的fsrec源码,驱动中展示了如何启动文件系统驱动程序,如何根据硬盘和光盘上的文件系统类型调用不同的文件系统驱动程序

/*++

Copyright (c) 1992  Microsoft Corporation

Module Name:

    cdfs_rec.c

Abstract:

    This module contains the mini-file system recognizer for CDFS.

Author:

    Darryl E. Havens (darrylh) 8-dec-1992

Environment:

    Kernel mode, local to I/O system

Revision History:


--*/

#include "fs_rec.h"

//
//  The local debug trace level
//

#define Dbg                              (FSREC_DEBUG_LEVEL_CDFS)

#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE,CdfsRecFsControl)
#endif // ALLOC_PRAGMA


NTSTATUS
CdfsRecFsControl(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:

    This function performs the mount and driver reload functions for this mini-
    file system recognizer driver.

Arguments:

    DeviceObject - Pointer to this driver's device object.

    Irp - Pointer to the I/O Request Packet (IRP) representing the function to
        be performed.

Return Value:

    The function value is the final status of the operation.


 -*/

{
    NTSTATUS status;
    PIO_STACK_LOCATION irpSp;
    PDEVICE_EXTENSION deviceExtension;

    PAGED_CODE();

    //
    // Begin by determining what function that is to be performed.
    //

    deviceExtension = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension;
    irpSp = IoGetCurrentIrpStackLocation( Irp );

    switch ( irpSp->MinorFunction ) {

    case IRP_MN_MOUNT_VOLUME:

        //
        //  Always request the filesystem driver.
        //
        
        status = STATUS_FS_DRIVER_REQUIRED;
        break;

    case IRP_MN_LOAD_FILE_SYSTEM:

        status = FsRecLoadFileSystem( DeviceObject,
                                      L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\Cdfs" );
        break;

    default:
        
        status = STATUS_INVALID_DEVICE_REQUEST;
        break;
    }

    //
    // Finally, complete the request and return the same status code to the
    // caller.
    //

    Irp->IoStatus.Status = status;
    IoCompleteRequest( Irp, IO_NO_INCREMENT );

    return status;
}