lockctrl.c

windows 2000中的UDF文件系统的驱动程序.只有读的功能,不支持未关闭的盘片.只支持UDF2.0以下版本,不支持VAT格式的UDF.

    //
    //  Decode the type of file object we're being asked to process and
    //  make sure that is is only a user file open.
    //

    TypeOfOpen = UdfFastDecodeFileObject( FileObject, &Fcb );

    if (TypeOfOpen != UserFileOpen) {

        IoStatus->Status = STATUS_INVALID_PARAMETER;
        return TRUE;
    }

    //
    //  Only deal with 'good' Fcb's.
    //

    if (!UdfVerifyFcbOperation( NULL, Fcb )) {

        return FALSE;
    }

    //
    //  If there is no lock then return immediately.
    //

    if (Fcb->FileLock == NULL) {

        IoStatus->Status = STATUS_RANGE_NOT_LOCKED;
        return TRUE;
    }

    FsRtlEnterFileSystem();

    try {

        //
        //  We check whether we can proceed based on the state of the file oplocks.
        //

        if ((Fcb->Oplock != NULL) && !FsRtlOplockIsFastIoPossible( &Fcb->Oplock )) {

            try_leave( NOTHING );
        }

        //
        //  If we don't have a file lock, then get one now.
        //

        if ((Fcb->FileLock == NULL) && !UdfCreateFileLock( NULL, Fcb, FALSE )) {

            try_leave( NOTHING );
        }

        //
        //  Now call the FsRtl routine to do the actual processing of the
        //  Lock request.  The call will always succeed.
        //

        Results = TRUE;
        IoStatus->Status = FsRtlFastUnlockSingle( Fcb->FileLock,
                                                  FileObject,
                                                  FileOffset,
                                                  Length,
                                                  ProcessId,
                                                  Key,
                                                  NULL,
                                                  FALSE );

        //
        //  Set the flag indicating if Fast I/O is possible.  We are
        //  only concerned if there are no longer any filelocks on this
        //  file.
        //

        if (!FsRtlAreThereCurrentFileLocks( Fcb->FileLock ) &&
            (Fcb->IsFastIoPossible != FastIoIsPossible)) {

            UdfLockFcb( IrpContext, Fcb );
            Fcb->IsFastIoPossible = UdfIsFastIoPossible( Fcb );
            UdfUnlockFcb( IrpContext, Fcb );
        }

    } finally {

        FsRtlExitFileSystem();
    }

    return Results;
}


BOOLEAN
UdfFastUnlockAll (
    IN PFILE_OBJECT FileObject,
    PEPROCESS ProcessId,
    OUT PIO_STATUS_BLOCK IoStatus,
    IN PDEVICE_OBJECT DeviceObject
    )

/*++

Routine Description:

    This is a call back routine for doing the fast unlock all call.

Arguments:

    FileObject - Supplies the file object used in this operation

    ProcessId - Supplies the process ID used in this operation

    Status - Receives the Status if this operation is successful

Return Value:

    BOOLEAN - TRUE if this operation completed and FALSE if caller
        needs to take the long route.

--*/

{
    BOOLEAN Results = FALSE;
    TYPE_OF_OPEN TypeOfOpen;
    PFCB Fcb;

    PAGED_CODE();

    IoStatus->Information = 0;

    //
    //  Decode the type of file object we're being asked to process and
    //  make sure that is is only a user file open.
    //

    TypeOfOpen = UdfFastDecodeFileObject( FileObject, &Fcb );

    if (TypeOfOpen != UserFileOpen) {

        IoStatus->Status = STATUS_INVALID_PARAMETER;
        return TRUE;
    }

    //
    //  Only deal with 'good' Fcb's.
    //

    if (!UdfVerifyFcbOperation( NULL, Fcb )) {

        return FALSE;
    }

    //
    //  If there is no lock then return immediately.
    //

    if (Fcb->FileLock == NULL) {

        IoStatus->Status = STATUS_RANGE_NOT_LOCKED;
        return TRUE;
    }

    FsRtlEnterFileSystem();

    try {

        //
        //  We check whether we can proceed based on the state of the file oplocks.
        //

        if ((Fcb->Oplock != NULL) && !FsRtlOplockIsFastIoPossible( &Fcb->Oplock )) {

            try_leave( NOTHING );
        }

        //
        //  If we don't have a file lock, then get one now.
        //

        if ((Fcb->FileLock == NULL) && !UdfCreateFileLock( NULL, Fcb, FALSE )) {

            try_leave( NOTHING );
        }

        //
        //  Now call the FsRtl routine to do the actual processing of the
        //  Lock request.  The call will always succeed.
        //

        Results = TRUE;
        IoStatus->Status = FsRtlFastUnlockAll( Fcb->FileLock,
                                               FileObject,
                                               ProcessId,
                                               NULL );


        //
        //  Set the flag indicating if Fast I/O is possible
        //

        UdfLockFcb( IrpContext, Fcb );
        Fcb->IsFastIoPossible = UdfIsFastIoPossible( Fcb );
        UdfUnlockFcb( IrpContext, Fcb );

    } finally {

        FsRtlExitFileSystem();
    }

    return Results;
}


BOOLEAN
UdfFastUnlockAllByKey (
    IN PFILE_OBJECT FileObject,
    PVOID ProcessId,
    ULONG Key,
    OUT PIO_STATUS_BLOCK IoStatus,
    IN PDEVICE_OBJECT DeviceObject
    )

/*++

Routine Description:

    This is a call back routine for doing the fast unlock all by key call.

Arguments:

    FileObject - Supplies the file object used in this operation

    ProcessId - Supplies the process ID used in this operation

    Key - Supplies the key used in this operation

    Status - Receives the Status if this operation is successful

Return Value:

    BOOLEAN - TRUE if this operation completed and FALSE if caller
        needs to take the long route.

--*/

{
    BOOLEAN Results = FALSE;
    TYPE_OF_OPEN TypeOfOpen;
    PFCB Fcb;

    PAGED_CODE();

    IoStatus->Information = 0;

    //
    //  Decode the type of file object we're being asked to process and
    //  make sure that is is only a user file open.
    //

    TypeOfOpen = UdfFastDecodeFileObject( FileObject, &Fcb );

    if (TypeOfOpen != UserFileOpen) {

        IoStatus->Status = STATUS_INVALID_PARAMETER;
        return TRUE;
    }

    //
    //  Only deal with 'good' Fcb's.
    //

    if (!UdfVerifyFcbOperation( NULL, Fcb )) {

        return FALSE;
    }

    //
    //  If there is no lock then return immediately.
    //

    if (Fcb->FileLock == NULL) {

        IoStatus->Status = STATUS_RANGE_NOT_LOCKED;
        return TRUE;
    }

    FsRtlEnterFileSystem();

    try {

        //
        //  We check whether we can proceed based on the state of the file oplocks.
        //

        if ((Fcb->Oplock != NULL) && !FsRtlOplockIsFastIoPossible( &Fcb->Oplock )) {

            try_leave( NOTHING );
        }

        //
        //  If we don't have a file lock, then get one now.
        //

        if ((Fcb->FileLock == NULL) && !UdfCreateFileLock( NULL, Fcb, FALSE )) {

            try_leave( NOTHING );
        }

        //
        //  Now call the FsRtl routine to do the actual processing of the
        //  Lock request.  The call will always succeed.
        //

        Results = TRUE;
        IoStatus->Status = FsRtlFastUnlockAllByKey( Fcb->FileLock,
                                                    FileObject,
                                                    ProcessId,
                                                    Key,
                                                    NULL );


        //
        //  Set the flag indicating if Fast I/O is possible
        //

        UdfLockFcb( IrpContext, Fcb );
        Fcb->IsFastIoPossible = UdfIsFastIoPossible( Fcb );
        UdfUnlockFcb( IrpContext, Fcb );

    } finally {

        FsRtlExitFileSystem();
    }

    return Results;
}