diskperf.c

The DiskPerf filter driver monitors disk-accesses, capturing performance data. It supports Plug and

    DriverObject - Disk performance driver object.
    PhysicalDeviceObject - Physical Device Object from the underlying layered driver

Return Value:

    NTSTATUS
--*/

{
    NTSTATUS                status;
    IO_STATUS_BLOCK         ioStatus;
    PDEVICE_OBJECT          filterDeviceObject;
    PDEVICE_EXTENSION       deviceExtension;
    CCHAR                   ntNameBuffer[DISKPERF_MAXSTR];
    STRING                  ntNameString;
    UNICODE_STRING          ntUnicodeString;
    PIRP                    irp;
    STORAGE_DEVICE_NUMBER   number;
    ULONG                   registrationFlag = 0;
    PWMILIB_CONTEXT         wmilibContext;
    PCHAR                   buffer;
    ULONG                   buffersize;

    PAGED_CODE();

    //
    // Create a filter device object for this device (partition).
    //

    DebugPrint((2, "DiskPerfAddDevice: Driver %X Device %X\n",
            DriverObject, PhysicalDeviceObject));

    status = IoCreateDevice(DriverObject,
                            DEVICE_EXTENSION_SIZE,
                            NULL,
                            FILE_DEVICE_DISK,
                            FILE_DEVICE_SECURE_OPEN,
                            FALSE,
                            &filterDeviceObject);

    if (!NT_SUCCESS(status)) {
       DebugPrint((1, "DiskPerfAddDevice: Cannot create filterDeviceObject\n"));
       return status;
    }

    filterDeviceObject->Flags |= DO_DIRECT_IO;

    deviceExtension = (PDEVICE_EXTENSION) filterDeviceObject->DeviceExtension;

    RtlZeroMemory(deviceExtension, DEVICE_EXTENSION_SIZE);
    DiskPerfGetClock(deviceExtension->LastIdleClock, NULL);
    DebugPrint((10, "DiskPerfAddDevice: LIC=%I64u\n",
                    deviceExtension->LastIdleClock));

    //
    // Allocate per processor counters. NOTE: To save some memory, it does
    // allocate memory beyond QueryTime. Remember to expand size if there
    // is a need to use anything beyond this
    //
    deviceExtension->Processors = KeNumberProcessors;
    buffersize= PROCESSOR_COUNTERS_SIZE * deviceExtension->Processors;
    buffer = (PCHAR) ExAllocatePool(NonPagedPool, buffersize);
    if (buffer != NULL) {
        RtlZeroMemory(buffer, buffersize);
        deviceExtension->DiskCounters = (PDISK_PERFORMANCE) buffer;
    }
    else {
        DiskPerfLogError(
            filterDeviceObject,
            513,
            STATUS_SUCCESS,
            IO_ERR_INSUFFICIENT_RESOURCES);
    }

    //
    // Attaches the device object to the highest device object in the chain and
    // return the previously highest device object, which is passed to
    // IoCallDriver when pass IRPs down the device stack
    //

    deviceExtension->PhysicalDeviceObject = PhysicalDeviceObject;

    deviceExtension->TargetDeviceObject =
        IoAttachDeviceToDeviceStack(filterDeviceObject, PhysicalDeviceObject);

    if (deviceExtension->TargetDeviceObject == NULL) {
        IoDeleteDevice(filterDeviceObject);
        DebugPrint((1, "DiskPerfAddDevice: Unable to attach %X to target %X\n",
            filterDeviceObject, PhysicalDeviceObject));
        return STATUS_NO_SUCH_DEVICE;
    }

    //
    // Save the filter device object in the device extension
    //
    deviceExtension->DeviceObject = filterDeviceObject;

    deviceExtension->PhysicalDeviceName.Buffer
            = deviceExtension->PhysicalDeviceNameBuffer;

    KeInitializeEvent(&deviceExtension->PagingPathCountEvent,
                      NotificationEvent, TRUE);


    //
    // Initialize WMI library context
    //
    wmilibContext = &deviceExtension->WmilibContext;
    RtlZeroMemory(wmilibContext, sizeof(WMILIB_CONTEXT));
    wmilibContext->GuidCount = DiskperfGuidCount;
    wmilibContext->GuidList = DiskperfGuidList;
    wmilibContext->QueryWmiRegInfo = DiskperfQueryWmiRegInfo;
    wmilibContext->QueryWmiDataBlock = DiskperfQueryWmiDataBlock;
    wmilibContext->WmiFunctionControl = DiskperfWmiFunctionControl;

    //
    // default to DO_POWER_PAGABLE
    //

    filterDeviceObject->Flags |=  DO_POWER_PAGABLE;

    //
    // Clear the DO_DEVICE_INITIALIZING flag
    //

    filterDeviceObject->Flags &= ~DO_DEVICE_INITIALIZING;

    return STATUS_SUCCESS;

} // end DiskPerfAddDevice()


NTSTATUS
DiskPerfDispatchPnp(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )
/*++

Routine Description:

    Dispatch for PNP

Arguments:

    DeviceObject    - Supplies the device object.

    Irp             - Supplies the I/O request packet.

Return Value:

    NTSTATUS

--*/

{
    PIO_STACK_LOCATION  irpSp = IoGetCurrentIrpStackLocation(Irp);
    NTSTATUS            status;
    PDEVICE_EXTENSION   deviceExtension;

    PAGED_CODE();

    DebugPrint((2, "DiskPerfDispatchPnp: Device %X Irp %X\n",
        DeviceObject, Irp));

    switch(irpSp->MinorFunction) {

        case IRP_MN_START_DEVICE:
            //
            // Call the Start Routine handler to schedule a completion routine
            //
            DebugPrint((3,
               "DiskPerfDispatchPnp: Schedule completion for START_DEVICE"));
            status = DiskPerfStartDevice(DeviceObject, Irp);
            break;

        case IRP_MN_REMOVE_DEVICE:
        {
            //
            // Call the Remove Routine handler to schedule a completion routine
            //
            DebugPrint((3,
               "DiskPerfDispatchPnp: Schedule completion for REMOVE_DEVICE"));
            status = DiskPerfRemoveDevice(DeviceObject, Irp);
            break;
        }
        case IRP_MN_DEVICE_USAGE_NOTIFICATION:
        {
            PIO_STACK_LOCATION irpStack;
            ULONG count;
            BOOLEAN setPagable;

            DebugPrint((3,
               "DiskPerfDispatchPnp: Processing DEVICE_USAGE_NOTIFICATION"));
            irpStack = IoGetCurrentIrpStackLocation(Irp);

            if (irpStack->Parameters.UsageNotification.Type != DeviceUsageTypePaging) {
                status = DiskPerfSendToNextDriver(DeviceObject, Irp);
                break; // out of case statement
            }

            deviceExtension = DeviceObject->DeviceExtension;

            //
            // wait on the paging path event
            //

            status = KeWaitForSingleObject(&deviceExtension->PagingPathCountEvent,
                                           Executive, KernelMode,
                                           FALSE, NULL);

            //
            // if removing last paging device, need to set DO_POWER_PAGABLE
            // bit here, and possible re-set it below on failure.
            //

            setPagable = FALSE;
            if (!irpStack->Parameters.UsageNotification.InPath &&
                deviceExtension->PagingPathCount == 1 ) {

                //
                // removing the last paging file
                // must have DO_POWER_PAGABLE bits set
                //

                if (DeviceObject->Flags & DO_POWER_INRUSH) {
                    DebugPrint((3, "DiskPerfDispatchPnp: last paging file "
                                "removed but DO_POWER_INRUSH set, so not "
                                "setting PAGABLE bit "
                                "for DO %p\n", DeviceObject));
                } else {
                    DebugPrint((2, "DiskPerfDispatchPnp: Setting  PAGABLE "
                                "bit for DO %p\n", DeviceObject));
                    DeviceObject->Flags |= DO_POWER_PAGABLE;
                    setPagable = TRUE;
                }

            }

            //
            // send the irp synchronously
            //

            status = DiskPerfForwardIrpSynchronous(DeviceObject, Irp);

            //
            // now deal with the failure and success cases.
            // note that we are not allowed to fail the irp
            // once it is sent to the lower drivers.
            //

            if (NT_SUCCESS(status)) {

                IoAdjustPagingPathCount(
                    &deviceExtension->PagingPathCount,
                    irpStack->Parameters.UsageNotification.InPath);

                if (irpStack->Parameters.UsageNotification.InPath) {
                    if (deviceExtension->PagingPathCount == 1) {

                        //
                        // first paging file addition
                        //

                        DebugPrint((3, "DiskPerfDispatchPnp: Clearing PAGABLE bit "
                                    "for DO %p\n", DeviceObject));
                        DeviceObject->Flags &= ~DO_POWER_PAGABLE;
                    }
                }

            } else {

                //
                // cleanup the changes done above
                //

                if (setPagable == TRUE) {
                    DeviceObject->Flags &= ~DO_POWER_PAGABLE;
                    setPagable = FALSE;
                }

            }

            //
            // set the event so the next one can occur.
            //

            KeSetEvent(&deviceExtension->PagingPathCountEvent,
                       IO_NO_INCREMENT, FALSE);

            //
            // and complete the irp
            //

            IoCompleteRequest(Irp, IO_NO_INCREMENT);
            return status;
            break;

        }

        default:
            DebugPrint((3,
               "DiskPerfDispatchPnp: Forwarding irp"));
            //
            // Simply forward all other Irps
            //
            return DiskPerfSendToNextDriver(DeviceObject, Irp);

    }

    return status;

} // end DiskPerfDispatchPnp()


NTSTATUS
DiskPerfIrpCompletion(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp,
    IN PVOID Context
    )

/*++

Routine Description:

    Forwarded IRP completion routine. Set an event and return
    STATUS_MORE_PROCESSING_REQUIRED. Irp forwarder will wait on this
    event and then re-complete the irp after cleaning up.

Arguments:

    DeviceObject is the device object of the WMI driver
    Irp is the WMI irp that was just completed
    Context is a PKEVENT that forwarder will wait on

Return Value:

    STATUS_MORE_PORCESSING_REQUIRED

--*/

{
    PKEVENT Event = (PKEVENT) Context;

    UNREFERENCED_PARAMETER(DeviceObject);
    UNREFERENCED_PARAMETER(Irp);

    KeSetEvent(Event, IO_NO_INCREMENT, FALSE);

    return(STATUS_MORE_PROCESSING_REQUIRED);

} // end DiskPerfIrpCompletion()


NTSTATUS
DiskPerfStartDevice(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )
/*++

Routine Description:

    This routine is called when a Pnp Start Irp is received.
    It will schedule a completion routine to initialize and register with WMI.

Arguments:

    DeviceObject - a pointer to the device object

    Irp - a pointer to the irp


Return Value:

    Status of processing the Start Irp

--*/
{
    PDEVICE_EXTENSION   deviceExtension;
    KEVENT              event;
    NTSTATUS            status;

    PAGED_CODE();

    deviceExtension = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension;

    status = DiskPerfForwardIrpSynchronous(DeviceObject, Irp);

    DiskPerfSyncFilterWithTarget(DeviceObject,
                                 deviceExtension->TargetDeviceObject);

    //
    // Complete WMI registration
    //
    DiskPerfRegisterDevice(DeviceObject);

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

    return status;
}


NTSTATUS
DiskPerfRemoveDevice(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )
/*++

Routine Description:

    This routine is called when the device is to be removed.
    It will de-register itself from WMI first, detach itself from the
    stack before deleting itself.

Arguments:

    DeviceObject - a pointer to the device object

    Irp - a pointer to the irp


Return Value:

    Status of removing the device

--*/
{
    NTSTATUS            status;
    PDEVICE_EXTENSION   deviceExtension;
    PWMILIB_CONTEXT     wmilibContext;

    PAGED_CODE();

    deviceExtension = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension;

    //
    // Remove registration with WMI first
    //
    IoWMIRegistrationControl(DeviceObject, WMIREG_ACTION_DEREGISTER);

    //
    // quickly zero out the count first to invalid the structure
    //
    wmilibContext = &deviceExtension->WmilibContext;
    InterlockedExchange(
        (PLONG) &(wmilibContext->GuidCount),
        (LONG) 0);
    RtlZeroMemory(wmilibContext, sizeof(WMILIB_CONTEXT));

    status = DiskPerfForwardIrpSynchronous(DeviceObject, Irp);

    IoDetachDevice(deviceExtension->TargetDeviceObject);
    IoDeleteDevice(DeviceObject);

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

    return status;
}