Exemple #1
0
/*++////////////////////////////////////////////////////////////////////////////

ClassDispatchPower()

Routine Description:

    This routine acquires the removelock for the irp and then calls the
    appropriate power callback.

Arguments:

    DeviceObject - 
    Irp - 

Return Value:

--*/
NTSTATUS
NTAPI
ClassDispatchPower(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )
{
    PCOMMON_DEVICE_EXTENSION commonExtension = DeviceObject->DeviceExtension;
    ULONG isRemoved;

    //
    // NOTE: This code may be called at PASSIVE or DISPATCH, depending
    //       upon the device object it is being called for.
    //       don't do anything that would break under either circumstance.
    //

    isRemoved = ClassAcquireRemoveLock(DeviceObject, Irp);

    if(isRemoved) {
        ClassReleaseRemoveLock(DeviceObject, Irp);
        Irp->IoStatus.Status = STATUS_DEVICE_DOES_NOT_EXIST;
        PoStartNextPowerIrp(Irp);
        ClassCompleteRequest(DeviceObject, Irp, IO_NO_INCREMENT);
        return STATUS_DEVICE_DOES_NOT_EXIST;
    }

    return commonExtension->DevInfo->ClassPowerDevice(DeviceObject, Irp);
} // end ClassDispatchPower()
Exemple #2
0
NTSTATUS TransferPktComplete(IN PDEVICE_OBJECT NullFdo, IN PIRP Irp, IN PVOID Context)
{
    PTRANSFER_PACKET pkt = (PTRANSFER_PACKET)Context;
    PFUNCTIONAL_DEVICE_EXTENSION fdoExt = pkt->Fdo->DeviceExtension;
    PCLASS_PRIVATE_FDO_DATA fdoData = fdoExt->PrivateFdoData;
    PIO_STACK_LOCATION origCurrentSp = IoGetCurrentIrpStackLocation(pkt->OriginalIrp);
    BOOLEAN packetDone = FALSE;

    /*
     *  Put all the assertions and spew in here so we don't have to look at them.
     */
    DBGCHECKRETURNEDPKT(pkt);    
    
    if (SRB_STATUS(pkt->Srb.SrbStatus) == SRB_STATUS_SUCCESS){
        
        fdoData->LoggedTURFailureSinceLastIO = FALSE;
        
        /*
         *  The port driver should not have allocated a sense buffer
         *  if the SRB succeeded.
         */
        ASSERT(!PORT_ALLOCATED_SENSE(fdoExt, &pkt->Srb));

        /*
         *  Add this packet's transferred length to the original IRP's.
         */
        InterlockedExchangeAdd((PLONG)&pkt->OriginalIrp->IoStatus.Information, 
                              (LONG)pkt->Srb.DataTransferLength);

        if (pkt->InLowMemRetry){
            packetDone = StepLowMemRetry(pkt);
        }
        else {
            packetDone = TRUE;
        }
        
    }
    else {
        /*
         *  The packet failed.  We may retry it if possible.
         */
        BOOLEAN shouldRetry;
        
        /*
         *  Make sure IRP status matches SRB error status (since we propagate it).
         */
        if (NT_SUCCESS(Irp->IoStatus.Status)){
            Irp->IoStatus.Status = STATUS_UNSUCCESSFUL;
        }

        /*
         *  Interpret the SRB error (to a meaningful IRP status)
         *  and determine if we should retry this packet.
         *  This call looks at the returned SENSE info to figure out what to do.
         */
        shouldRetry = InterpretTransferPacketError(pkt);

        /*
         *  Sometimes the port driver can allocates a new 'sense' buffer
         *  to report transfer errors, e.g. when the default sense buffer
         *  is too small.  If so, it is up to us to free it.
         *  Now that we're done interpreting the sense info, free it if appropriate.
         */
        if (PORT_ALLOCATED_SENSE(fdoExt, &pkt->Srb)) {
            DBGTRACE(ClassDebugSenseInfo, ("Freeing port-allocated sense buffer for pkt %ph.", pkt));
            FREE_PORT_ALLOCATED_SENSE_BUFFER(fdoExt, &pkt->Srb);
            pkt->Srb.SenseInfoBuffer = &pkt->SrbErrorSenseData;
            pkt->Srb.SenseInfoBufferLength = sizeof(SENSE_DATA);
        }

        /*
         *  If the SRB queue is locked-up, release it.
         *  Do this after calling the error handler.
         */
        if (pkt->Srb.SrbStatus & SRB_STATUS_QUEUE_FROZEN){
            ClassReleaseQueue(pkt->Fdo);
        }
        
        if (shouldRetry && (pkt->NumRetries > 0)){           
            packetDone = RetryTransferPacket(pkt);
        }
        else {
            packetDone = TRUE;
        }
        
    }

    /*
     *  If the packet is completed, put it back in the free list.
     *  If it is the last packet servicing the original request, complete the original irp.
     */
    if (packetDone){
        LONG numPacketsRemaining;
        PIRP deferredIrp;
        PDEVICE_OBJECT Fdo = pkt->Fdo;
        UCHAR uniqueAddr;
        
        /*
         *  In case a remove is pending, bump the lock count so we don't get freed
         *  right after we complete the original irp.
         */
        ClassAcquireRemoveLock(Fdo, (PIRP)&uniqueAddr);        

        /*
         *  The original IRP should get an error code
         *  if any one of the packets failed.
         */
        if (!NT_SUCCESS(Irp->IoStatus.Status)){
            pkt->OriginalIrp->IoStatus.Status = Irp->IoStatus.Status;

            /*
             *  If the original I/O originated in user space (i.e. it is thread-queued), 
             *  and the error is user-correctable (e.g. media is missing, for removable media),
             *  alert the user.
             *  Since this is only one of possibly several packets completing for the original IRP,
             *  we may do this more than once for a single request.  That's ok; this allows
             *  us to test each returned status with IoIsErrorUserInduced().
             */
            if (IoIsErrorUserInduced(Irp->IoStatus.Status) &&
                pkt->CompleteOriginalIrpWhenLastPacketCompletes &&
                pkt->OriginalIrp->Tail.Overlay.Thread){

                IoSetHardErrorOrVerifyDevice(pkt->OriginalIrp, pkt->Fdo);
            }
        }

        /*
         *  We use a field in the original IRP to count
         *  down the transfer pieces as they complete.
         */
        numPacketsRemaining = InterlockedDecrement(
            (PLONG)&pkt->OriginalIrp->Tail.Overlay.DriverContext[0]);
            
        if (numPacketsRemaining > 0){
            /*
             *  More transfer pieces remain for the original request.
             *  Wait for them to complete before completing the original irp.
             */
        }
        else {

            /*
             *  All the transfer pieces are done.
             *  Complete the original irp if appropriate.
             */
            ASSERT(numPacketsRemaining == 0);
            if (pkt->CompleteOriginalIrpWhenLastPacketCompletes){  
                if (NT_SUCCESS(pkt->OriginalIrp->IoStatus.Status)){
                    ASSERT((ULONG)pkt->OriginalIrp->IoStatus.Information == origCurrentSp->Parameters.Read.Length);
                    ClasspPerfIncrementSuccessfulIo(fdoExt);
                }
                ClassReleaseRemoveLock(pkt->Fdo, pkt->OriginalIrp);

                ClassCompleteRequest(pkt->Fdo, pkt->OriginalIrp, IO_DISK_INCREMENT);

                /*
                 *  We may have been called by one of the class drivers (e.g. cdrom)
                 *  via the legacy API ClassSplitRequest.  
                 *  This is the only case for which the packet engine is called for an FDO
                 *  with a StartIo routine; in that case, we have to call IoStartNextPacket
                 *  now that the original irp has been completed.
                 */
                if (fdoExt->CommonExtension.DriverExtension->InitData.ClassStartIo) {
                    if (TEST_FLAG(pkt->Srb.SrbFlags, SRB_FLAGS_DONT_START_NEXT_PACKET)){
                        DBGTRAP(("SRB_FLAGS_DONT_START_NEXT_PACKET should never be set here (?)"));
                    }
                    else {
                        KIRQL oldIrql;
                        KeRaiseIrql(DISPATCH_LEVEL, &oldIrql);
                        IoStartNextPacket(pkt->Fdo, FALSE);
                        KeLowerIrql(oldIrql);
                    }
                }              
            }            
        }

        /*
         *  If the packet was synchronous, write the final
         *  result back to the issuer's status buffer and
         *  signal his event.
         */
        if (pkt->SyncEventPtr){
            KeSetEvent(pkt->SyncEventPtr, 0, FALSE);
            pkt->SyncEventPtr = NULL;
        }

        /*
         *  Free the completed packet.
         */
        pkt->OriginalIrp = NULL;
        pkt->InLowMemRetry = FALSE;
        EnqueueFreeTransferPacket(pkt->Fdo, pkt);

        /*
         *  Now that we have freed some resources,
         *  try again to send one of the previously deferred irps.
         */
        deferredIrp = DequeueDeferredClientIrp(fdoData);
        if (deferredIrp){
            DBGWARN(("... retrying deferred irp %xh.", deferredIrp)); 
            ServiceTransferRequest(pkt->Fdo, deferredIrp);
        }

        ClassReleaseRemoveLock(Fdo, (PIRP)&uniqueAddr);        
    }

    return STATUS_MORE_PROCESSING_REQUIRED;
}
Exemple #3
0
/*++////////////////////////////////////////////////////////////////////////////

ClassIoCompleteAssociated()

Routine Description:

    This routine executes when the port driver has completed a request.
    It looks at the SRB status in the completing SRB and if not success
    it checks for valid request sense buffer information. If valid, the
    info is used to update status with more precise message of type of
    error. This routine deallocates the SRB.  This routine is used for
    requests which were build by split request.  After it has processed
    the request it decrements the Irp count in the master Irp.  If the
    count goes to zero then the master Irp is completed.

Arguments:

    Fdo - Supplies the functional device object which represents the target.

    Irp - Supplies the Irp which has completed.

    Context - Supplies a pointer to the SRB.

Return Value:

    NT status

--*/
NTSTATUS
NTAPI
ClassIoCompleteAssociated(
    IN PDEVICE_OBJECT Fdo,
    IN PIRP Irp,
    IN PVOID Context
    )
{
    PFUNCTIONAL_DEVICE_EXTENSION fdoExtension = Fdo->DeviceExtension;

    PIO_STACK_LOCATION irpStack = IoGetCurrentIrpStackLocation(Irp);
    PSCSI_REQUEST_BLOCK srb = Context;

    PIRP originalIrp = Irp->AssociatedIrp.MasterIrp;
    LONG irpCount;

    NTSTATUS status;
    BOOLEAN retry;

    DBGWARN(("ClassIoCompleteAssociated is OBSOLETE !"));

    //
    // Check SRB status for success of completing request.
    //

    if (SRB_STATUS(srb->SrbStatus) != SRB_STATUS_SUCCESS) {

        ULONG retryInterval;

        DebugPrint((2,"ClassIoCompleteAssociated: IRP %p, SRB %p", Irp, srb));

        //
        // Release the queue if it is frozen.
        //

        if (srb->SrbStatus & SRB_STATUS_QUEUE_FROZEN) {
            ClassReleaseQueue(Fdo);
        }

        retry = ClassInterpretSenseInfo(
                    Fdo,
                    srb,
                    irpStack->MajorFunction,
                    irpStack->MajorFunction == IRP_MJ_DEVICE_CONTROL ?
                        irpStack->Parameters.DeviceIoControl.IoControlCode :
                        0,
                    MAXIMUM_RETRIES -
                        ((ULONG)(ULONG_PTR)irpStack->Parameters.Others.Argument4),
                    &status,
                    &retryInterval);

        //
        // If the status is verified required and the this request
        // should bypass verify required then retry the request.
        //

        if (irpStack->Flags & SL_OVERRIDE_VERIFY_VOLUME &&
            status == STATUS_VERIFY_REQUIRED) {

            status = STATUS_IO_DEVICE_ERROR;
            retry = TRUE;
        }

        if (retry && ((*(PCHAR*)&irpStack->Parameters.Others.Argument4)--)) {

            //
            // Retry request. If the class driver has supplied a StartIo,
            // call it directly for retries.
            //

            DebugPrint((1, "Retry request %p\n", Irp));

            if (PORT_ALLOCATED_SENSE(fdoExtension, srb)) {
                FREE_PORT_ALLOCATED_SENSE_BUFFER(fdoExtension, srb);
            }

            RetryRequest(Fdo, Irp, srb, TRUE, retryInterval);

            return STATUS_MORE_PROCESSING_REQUIRED;
        }

    } else {

        //
        // Set status for successful request.
        //

        status = STATUS_SUCCESS;

    } // end if (SRB_STATUS(srb->SrbStatus) ...

    //
    // Return SRB to list.
    //

    if (PORT_ALLOCATED_SENSE(fdoExtension, srb)) {
        FREE_PORT_ALLOCATED_SENSE_BUFFER(fdoExtension, srb);
    }

    ClassFreeOrReuseSrb(fdoExtension, srb);

    //
    // Set status in completing IRP.
    //

    Irp->IoStatus.Status = status;

    DebugPrint((2, "ClassIoCompleteAssociated: Partial xfer IRP %p\n", Irp));

    //
    // Get next stack location. This original request is unused
    // except to keep track of the completing partial IRPs so the
    // stack location is valid.
    //

    irpStack = IoGetNextIrpStackLocation(originalIrp);

    //
    // Update status only if error so that if any partial transfer
    // completes with error, then the original IRP will return with
    // error. If any of the asynchronous partial transfer IRPs fail,
    // with an error then the original IRP will return 0 bytes transfered.
    // This is an optimization for successful transfers.
    //

    if (!NT_SUCCESS(status)) {

        originalIrp->IoStatus.Status = status;
        originalIrp->IoStatus.Information = 0;

        //
        // Set the hard error if necessary.
        //

        if (IoIsErrorUserInduced(status)) {

            //
            // Store DeviceObject for filesystem.
            //

            IoSetHardErrorOrVerifyDevice(originalIrp, Fdo);
        }
    }

    //
    // Decrement and get the count of remaining IRPs.
    //

    irpCount = InterlockedDecrement(
                    (PLONG)&irpStack->Parameters.Others.Argument1);

    DebugPrint((2, "ClassIoCompleteAssociated: Partial IRPs left %d\n",
                irpCount));

    //
    // Ensure that the irpCount doesn't go negative.  This was happening once
    // because classpnp would get confused if it ran out of resources when
    // splitting the request.
    //

    ASSERT(irpCount >= 0);

    if (irpCount == 0) {

        //
        // All partial IRPs have completed.
        //

        DebugPrint((2,
                 "ClassIoCompleteAssociated: All partial IRPs complete %p\n",
                 originalIrp));

        if (fdoExtension->CommonExtension.DriverExtension->InitData.ClassStartIo) {

            //
            // Acquire a separate copy of the remove lock so the debugging code
            // works okay and we don't have to hold up the completion of this
            // irp until after we start the next packet(s).
            //

            KIRQL oldIrql;
            UCHAR uniqueAddress;
            ClassAcquireRemoveLock(Fdo, (PIRP)&uniqueAddress);
            ClassReleaseRemoveLock(Fdo, originalIrp);
            ClassCompleteRequest(Fdo, originalIrp, IO_DISK_INCREMENT);

            KeRaiseIrql(DISPATCH_LEVEL, &oldIrql);
            IoStartNextPacket(Fdo, FALSE);
            KeLowerIrql(oldIrql);

            ClassReleaseRemoveLock(Fdo, (PIRP)&uniqueAddress);

        } else {

            //
            // just complete this request
            //

            ClassReleaseRemoveLock(Fdo, originalIrp);
            ClassCompleteRequest(Fdo, originalIrp, IO_DISK_INCREMENT);

        }

    }

    //
    // Deallocate IRP and indicate the I/O system should not attempt any more
    // processing.
    //

    IoFreeIrp(Irp);
    return STATUS_MORE_PROCESSING_REQUIRED;

} // end ClassIoCompleteAssociated()
Exemple #4
0
/*++////////////////////////////////////////////////////////////////////////////

ClassWmiCompleteRequest()

Routine Description:


    This routine will do the work of completing a WMI irp. Depending upon the
    the WMI request this routine will fixup the returned WNODE appropriately.

    NOTE: This routine assumes that the ClassRemoveLock is held and it will
          release it.

Arguments:

    DeviceObject - Supplies a pointer to the device object for this request.

    Irp - Supplies the Irp making the request.
    
    Status - Status to complete the irp with.  STATUS_BUFFER_TOO_SMALL is used
        to indicate that more buffer is required for the data requested.
    
    BufferUsed - number of bytes of actual data to return (not including WMI
        specific structures)
    
    PriorityBoost - priority boost to pass to ClassCompleteRequest

Return Value:

    status

--*/
SCSIPORTAPI
NTSTATUS
NTAPI
ClassWmiCompleteRequest(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp,
    IN NTSTATUS Status,
    IN ULONG BufferUsed,
    IN CCHAR PriorityBoost
    )
{
    PCOMMON_DEVICE_EXTENSION commonExtension = DeviceObject->DeviceExtension;
    PIO_STACK_LOCATION irpStack = IoGetCurrentIrpStackLocation(Irp);
    //UCHAR MinorFunction;
    PUCHAR buffer;
    ULONG retSize;
    UCHAR minorFunction;
    ULONG bufferSize;

    minorFunction = irpStack->MinorFunction;
    buffer = (PUCHAR)irpStack->Parameters.WMI.Buffer;
    bufferSize = irpStack->Parameters.WMI.BufferSize;

    switch(minorFunction)
    {
        case IRP_MN_QUERY_ALL_DATA:
        {
            PWNODE_ALL_DATA wnode;
            PWNODE_TOO_SMALL wnodeTooSmall;
            ULONG bufferNeeded;

            wnode = (PWNODE_ALL_DATA)buffer;

            bufferNeeded = sizeof(WNODE_ALL_DATA) + BufferUsed;

            if (NT_SUCCESS(Status))
            {
                retSize = bufferNeeded;
                wnode->WnodeHeader.BufferSize = bufferNeeded;
                KeQuerySystemTime(&wnode->WnodeHeader.TimeStamp);
                wnode->WnodeHeader.Flags |= WNODE_FLAG_FIXED_INSTANCE_SIZE;
                wnode->FixedInstanceSize = BufferUsed;
                wnode->InstanceCount = 1;

            } else if (Status == STATUS_BUFFER_TOO_SMALL) {
                wnodeTooSmall = (PWNODE_TOO_SMALL)wnode;

                wnodeTooSmall->WnodeHeader.BufferSize = sizeof(WNODE_TOO_SMALL);
                wnodeTooSmall->WnodeHeader.Flags = WNODE_FLAG_TOO_SMALL;
                wnodeTooSmall->SizeNeeded = sizeof(WNODE_ALL_DATA) + BufferUsed;
                retSize = sizeof(WNODE_TOO_SMALL);
                Status = STATUS_SUCCESS;
            } else {
                retSize = 0;
            }
            break;
        }

        case IRP_MN_QUERY_SINGLE_INSTANCE:
        {
            PWNODE_SINGLE_INSTANCE wnode;
            PWNODE_TOO_SMALL wnodeTooSmall;
            ULONG bufferNeeded;

            wnode = (PWNODE_SINGLE_INSTANCE)buffer;

            bufferNeeded = wnode->DataBlockOffset + BufferUsed;

            if (NT_SUCCESS(Status))
            {
                retSize = bufferNeeded;
                wnode->WnodeHeader.BufferSize = bufferNeeded;
                KeQuerySystemTime(&wnode->WnodeHeader.TimeStamp);
                wnode->SizeDataBlock = BufferUsed;

            } else if (Status == STATUS_BUFFER_TOO_SMALL) {
                wnodeTooSmall = (PWNODE_TOO_SMALL)wnode;

                wnodeTooSmall->WnodeHeader.BufferSize = sizeof(WNODE_TOO_SMALL);
                wnodeTooSmall->WnodeHeader.Flags = WNODE_FLAG_TOO_SMALL;
                wnodeTooSmall->SizeNeeded = bufferNeeded;
                retSize = sizeof(WNODE_TOO_SMALL);
                Status = STATUS_SUCCESS;
            } else {
                retSize = 0;
            }
            break;
        }

        case IRP_MN_EXECUTE_METHOD:
        {
            PWNODE_METHOD_ITEM wnode;
            PWNODE_TOO_SMALL wnodeTooSmall;
            ULONG bufferNeeded;

            wnode = (PWNODE_METHOD_ITEM)buffer;

            bufferNeeded = wnode->DataBlockOffset + BufferUsed;

            if (NT_SUCCESS(Status))
            {
                retSize = bufferNeeded;
                wnode->WnodeHeader.BufferSize = bufferNeeded;
                KeQuerySystemTime(&wnode->WnodeHeader.TimeStamp);
                wnode->SizeDataBlock = BufferUsed;

            } else if (Status == STATUS_BUFFER_TOO_SMALL) {
                wnodeTooSmall = (PWNODE_TOO_SMALL)wnode;

                wnodeTooSmall->WnodeHeader.BufferSize = sizeof(WNODE_TOO_SMALL);
                wnodeTooSmall->WnodeHeader.Flags = WNODE_FLAG_TOO_SMALL;
                wnodeTooSmall->SizeNeeded = bufferNeeded;
                retSize = sizeof(WNODE_TOO_SMALL);
                Status = STATUS_SUCCESS;
            } else {
                retSize = 0;
            }
            break;
        }

        default:
        {
            //
            // All other requests don't return any data
            retSize = 0;
            break;
        }

    }

    Irp->IoStatus.Status = Status;
    Irp->IoStatus.Information = retSize;
    ClassReleaseRemoveLock(DeviceObject, Irp);
    ClassCompleteRequest(DeviceObject, Irp, PriorityBoost);
    return(Status);
} // end ClassWmiCompleteRequest()
Exemple #5
0
/*++////////////////////////////////////////////////////////////////////////////

ClassSystemControl()

Routine Description:

    Dispatch routine for IRP_MJ_SYSTEM_CONTROL. This routine will process
    all wmi requests received, forwarding them if they are not for this
    driver or determining if the guid is valid and if so passing it to
    the driver specific function for handing wmi requests.

Arguments:

    DeviceObject - Supplies a pointer to the device object for this request.

    Irp - Supplies the Irp making the request.

Return Value:

    status

--*/
NTSTATUS
NTAPI
ClassSystemControl(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )
{
    PCOMMON_DEVICE_EXTENSION commonExtension = DeviceObject->DeviceExtension;
    PCLASS_DRIVER_EXTENSION driverExtension;
    PIO_STACK_LOCATION irpStack = IoGetCurrentIrpStackLocation(Irp);
    ULONG isRemoved;
    ULONG bufferSize;
    PUCHAR buffer;
    NTSTATUS status;
    UCHAR minorFunction;
    ULONG guidIndex;
    PCLASS_WMI_INFO classWmiInfo;

    PAGED_CODE();

    //
    // Make sure device has not been removed
    isRemoved = ClassAcquireRemoveLock(DeviceObject, Irp);
    if(isRemoved)
    {
        Irp->IoStatus.Status = STATUS_DEVICE_DOES_NOT_EXIST;
        ClassReleaseRemoveLock(DeviceObject, Irp);
        ClassCompleteRequest(DeviceObject, Irp, IO_NO_INCREMENT);
        return STATUS_DEVICE_DOES_NOT_EXIST;
    }

    //
    // If the irp is not a WMI irp or it is not targetted at this device
    // or this device has not regstered with WMI then just forward it on.
    minorFunction = irpStack->MinorFunction;
    if ((minorFunction > IRP_MN_EXECUTE_METHOD) ||
        (irpStack->Parameters.WMI.ProviderId != (ULONG_PTR)DeviceObject) ||
        ((minorFunction != IRP_MN_REGINFO) &&
         (commonExtension->GuidRegInfo == NULL)))
    {
        //
        // CONSIDER: Do I need to hang onto lock until IoCallDriver returns ?
        IoSkipCurrentIrpStackLocation(Irp);
        ClassReleaseRemoveLock(DeviceObject, Irp);
        return(IoCallDriver(commonExtension->LowerDeviceObject, Irp));
    }

    buffer = (PUCHAR)irpStack->Parameters.WMI.Buffer;
    bufferSize = irpStack->Parameters.WMI.BufferSize;

    if (minorFunction != IRP_MN_REGINFO)
    {
        //
        // For all requests other than query registration info we are passed
        // a guid. Determine if the guid is one that is supported by the
        // device.
        if (ClassFindGuid(commonExtension->GuidRegInfo,
                            commonExtension->GuidCount,
                            (LPGUID)irpStack->Parameters.WMI.DataPath,
                            &guidIndex))
        {
            status = STATUS_SUCCESS;
        } else {
            status = STATUS_WMI_GUID_NOT_FOUND;
        }

        if (NT_SUCCESS(status) &&
            ((minorFunction == IRP_MN_QUERY_SINGLE_INSTANCE) ||
             (minorFunction == IRP_MN_CHANGE_SINGLE_INSTANCE) ||
             (minorFunction == IRP_MN_CHANGE_SINGLE_ITEM) ||
             (minorFunction == IRP_MN_EXECUTE_METHOD)))
        {
            if ( (((PWNODE_HEADER)buffer)->Flags) &
                                          WNODE_FLAG_STATIC_INSTANCE_NAMES)
            {
                if ( ((PWNODE_SINGLE_INSTANCE)buffer)->InstanceIndex != 0 )
                {
                    status = STATUS_WMI_INSTANCE_NOT_FOUND;
                }
            } else {
                status = STATUS_WMI_INSTANCE_NOT_FOUND;
            }
        }

        if (! NT_SUCCESS(status))
        {
            Irp->IoStatus.Status = status;
            ClassReleaseRemoveLock(DeviceObject, Irp);
            ClassCompleteRequest(DeviceObject, Irp, IO_NO_INCREMENT);
            return(status);
        }
    }

    driverExtension = commonExtension->DriverExtension;

    classWmiInfo = commonExtension->IsFdo ?
                           &driverExtension->InitData.FdoData.ClassWmiInfo :
                           &driverExtension->InitData.PdoData.ClassWmiInfo;
    switch(minorFunction)
    {
        case IRP_MN_REGINFO:
        {
            ULONG guidCount;
            PGUIDREGINFO guidList;
            PWMIREGINFOW wmiRegInfo;
            PWMIREGGUIDW wmiRegGuid;
            //PDEVICE_OBJECT pdo;
            PUNICODE_STRING regPath;
            PWCHAR stringPtr;
            ULONG retSize;
            ULONG registryPathOffset;
            ULONG mofResourceOffset;
            ULONG bufferNeeded;
            ULONG i;
            ULONG_PTR nameInfo;
            ULONG nameSize, nameOffset, nameFlags;
            UNICODE_STRING name, mofName;
            PCLASS_QUERY_WMI_REGINFO_EX ClassQueryWmiRegInfoEx;

            name.Buffer = NULL;
            name.Length = 0;
            name.MaximumLength = 0;
            nameFlags = 0;

            ClassQueryWmiRegInfoEx = commonExtension->IsFdo ?
                               driverExtension->ClassFdoQueryWmiRegInfoEx :
                               driverExtension->ClassPdoQueryWmiRegInfoEx;
        
            if (ClassQueryWmiRegInfoEx == NULL)
            {
                status = classWmiInfo->ClassQueryWmiRegInfo(
                                                        DeviceObject,
                                                        &nameFlags,
                                                        &name);
                
                RtlInitUnicodeString(&mofName, MOFRESOURCENAME);
            } else {
                RtlInitUnicodeString(&mofName, L"");
                status = (*ClassQueryWmiRegInfoEx)(
                                                    DeviceObject,
                                                    &nameFlags,
                                                    &name,
                                                    &mofName);
            }

            if (NT_SUCCESS(status) &&
                (! (nameFlags &  WMIREG_FLAG_INSTANCE_PDO) &&
                (name.Buffer == NULL)))
            {
                //
                // if PDO flag not specified then an instance name must be
                status = STATUS_INVALID_DEVICE_REQUEST;
            }

            if (NT_SUCCESS(status))
            {
                guidList = classWmiInfo->GuidRegInfo;
                guidCount = classWmiInfo->GuidCount;

                nameOffset = sizeof(WMIREGINFO) +
                                      guidCount * sizeof(WMIREGGUIDW);

                if (nameFlags & WMIREG_FLAG_INSTANCE_PDO)
                {
                    nameSize = 0;
                    nameInfo = commonExtension->IsFdo ?
                                   (ULONG_PTR)((PFUNCTIONAL_DEVICE_EXTENSION)commonExtension)->LowerPdo :
                                   (ULONG_PTR)DeviceObject;
                } else {
                    nameFlags |= WMIREG_FLAG_INSTANCE_LIST;
                    nameSize = name.Length + sizeof(USHORT);
                    nameInfo = nameOffset;
                }

                mofResourceOffset = nameOffset + nameSize;

                registryPathOffset = mofResourceOffset +
                                  mofName.Length + sizeof(USHORT);

                regPath = &driverExtension->RegistryPath;
                bufferNeeded = registryPathOffset +
                regPath->Length + sizeof(USHORT);

                if (bufferNeeded <= bufferSize)
                {
                    retSize = bufferNeeded;

                    commonExtension->GuidCount = guidCount;
                    commonExtension->GuidRegInfo = guidList;

                    wmiRegInfo = (PWMIREGINFO)buffer;
                    wmiRegInfo->BufferSize = bufferNeeded;
                    wmiRegInfo->NextWmiRegInfo = 0;
                    wmiRegInfo->MofResourceName = mofResourceOffset;
                    wmiRegInfo->RegistryPath = registryPathOffset;
                    wmiRegInfo->GuidCount = guidCount;

                    for (i = 0; i < guidCount; i++)
                    {
                        wmiRegGuid = &wmiRegInfo->WmiRegGuid[i];
                        wmiRegGuid->Guid = guidList[i].Guid;
                        wmiRegGuid->Flags = guidList[i].Flags | nameFlags;
                        wmiRegGuid->InstanceInfo = nameInfo;
                        wmiRegGuid->InstanceCount = 1;
                    }

                    if ( nameFlags &  WMIREG_FLAG_INSTANCE_LIST)
                    {
                        stringPtr = (PWCHAR)((PUCHAR)buffer + nameOffset);
                        *stringPtr++ = name.Length;
                        RtlCopyMemory(stringPtr,
                                  name.Buffer,
                                  name.Length);
                    }

                    stringPtr = (PWCHAR)((PUCHAR)buffer + mofResourceOffset);
                    *stringPtr++ = mofName.Length;
                    RtlCopyMemory(stringPtr,
                                  mofName.Buffer,
                                  mofName.Length);

                    stringPtr = (PWCHAR)((PUCHAR)buffer + registryPathOffset);
                    *stringPtr++ = regPath->Length;
                    RtlCopyMemory(stringPtr,
                              regPath->Buffer,
                              regPath->Length);
                } else {
                    *((PULONG)buffer) = bufferNeeded;
                    retSize = sizeof(ULONG);
                }
            } else {
                retSize = 0;
            }

            if (name.Buffer != NULL)
            {
                ExFreePool(name.Buffer);
            }

            Irp->IoStatus.Status = status;
            Irp->IoStatus.Information = retSize;
            ClassReleaseRemoveLock(DeviceObject, Irp);
            ClassCompleteRequest(DeviceObject, Irp, IO_NO_INCREMENT);
            return(status);
        }

        case IRP_MN_QUERY_ALL_DATA:
        {
            PWNODE_ALL_DATA wnode;
            ULONG bufferAvail;

            wnode = (PWNODE_ALL_DATA)buffer;

            if (bufferSize < sizeof(WNODE_ALL_DATA))
            {
                bufferAvail = 0;
            } else {
                bufferAvail = bufferSize - sizeof(WNODE_ALL_DATA);
            }

            wnode->DataBlockOffset = sizeof(WNODE_ALL_DATA);

            status = classWmiInfo->ClassQueryWmiDataBlock(
                                             DeviceObject,
                                             Irp,
                                             guidIndex,
                                             bufferAvail,
                                             buffer + sizeof(WNODE_ALL_DATA));

            break;
        }

        case IRP_MN_QUERY_SINGLE_INSTANCE:
        {
            PWNODE_SINGLE_INSTANCE wnode;
            ULONG dataBlockOffset;

            wnode = (PWNODE_SINGLE_INSTANCE)buffer;

            dataBlockOffset = wnode->DataBlockOffset;

            status = classWmiInfo->ClassQueryWmiDataBlock(
                                          DeviceObject,
                                          Irp,
                                          guidIndex,
                                          bufferSize - dataBlockOffset,
                                          (PUCHAR)wnode + dataBlockOffset);

            break;
        }

        case IRP_MN_CHANGE_SINGLE_INSTANCE:
        {
            PWNODE_SINGLE_INSTANCE wnode;

            wnode = (PWNODE_SINGLE_INSTANCE)buffer;

            status = classWmiInfo->ClassSetWmiDataBlock(
                                     DeviceObject,
                                     Irp,
                                     guidIndex,
                                     wnode->SizeDataBlock,
                                     (PUCHAR)wnode + wnode->DataBlockOffset);

            break;
        }

        case IRP_MN_CHANGE_SINGLE_ITEM:
        {
            PWNODE_SINGLE_ITEM wnode;

            wnode = (PWNODE_SINGLE_ITEM)buffer;

            status = classWmiInfo->ClassSetWmiDataItem(
                                     DeviceObject,
                                     Irp,
                                     guidIndex,
                                     wnode->ItemId,
                                     wnode->SizeDataItem,
                                     (PUCHAR)wnode + wnode->DataBlockOffset);

            break;
        }

        case IRP_MN_EXECUTE_METHOD:
        {
            PWNODE_METHOD_ITEM wnode;

            wnode = (PWNODE_METHOD_ITEM)buffer;

            status = classWmiInfo->ClassExecuteWmiMethod(
                                         DeviceObject,
                                         Irp,
                                         guidIndex,
                                         wnode->MethodId,
                                         wnode->SizeDataBlock,
                                         bufferSize - wnode->DataBlockOffset,
                                         buffer + wnode->DataBlockOffset);


            break;
        }

        case IRP_MN_ENABLE_EVENTS:
        {
            status = classWmiInfo->ClassWmiFunctionControl(
                                                           DeviceObject,
                                                           Irp,
                                                           guidIndex,
                                                           EventGeneration,
                                                           TRUE);
            break;
        }

        case IRP_MN_DISABLE_EVENTS:
        {
            status = classWmiInfo->ClassWmiFunctionControl(
                                                           DeviceObject,
                                                           Irp,
                                                           guidIndex,
                                                           EventGeneration,
                                                           FALSE);
            break;
        }

        case IRP_MN_ENABLE_COLLECTION:
        {
            status = classWmiInfo->ClassWmiFunctionControl(
                                                         DeviceObject,
                                                         Irp,
                                                         guidIndex,
                                                         DataBlockCollection,
                                                         TRUE);
            break;
        }

        case IRP_MN_DISABLE_COLLECTION:
        {
            status = classWmiInfo->ClassWmiFunctionControl(
                                                         DeviceObject,
                                                         Irp,
                                                         guidIndex,
                                                         DataBlockCollection,
                                                         FALSE);
            break;
        }

        default:
        {
            status = STATUS_INVALID_DEVICE_REQUEST;
            break;
        }

    }

    return(status);
} // end ClassSystemControl()
Exemple #6
0
NTSTATUS
NTAPI
ClassCreateClose(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:

    SCSI class driver create and close routine.  This is called by the I/O system
    when the device is opened or closed.

Arguments:

    DriverObject - Pointer to driver object created by system.

    Irp - IRP involved.

Return Value:

    Device-specific drivers return value or STATUS_SUCCESS.

--*/

{
    PCOMMON_DEVICE_EXTENSION commonExtension = DeviceObject->DeviceExtension;
    ULONG removeState;
    NTSTATUS status;

    PAGED_CODE();

    //
    // If we're getting a close request then we know the device object hasn't
    // been completely destroyed.  Let the driver cleanup if necessary.
    //

    removeState = ClassAcquireRemoveLock(DeviceObject, Irp);

    //
    // Invoke the device-specific routine, if one exists. Otherwise complete
    // with SUCCESS
    //

    if((removeState == NO_REMOVE) ||
       IS_CLEANUP_REQUEST(IoGetCurrentIrpStackLocation(Irp)->MajorFunction)) {

        status = ClasspCreateClose(DeviceObject, Irp);

        if((NT_SUCCESS(status)) &&
           (commonExtension->DevInfo->ClassCreateClose)) {

            return commonExtension->DevInfo->ClassCreateClose(DeviceObject, Irp);
        }

    } else {
        status = STATUS_DEVICE_DOES_NOT_EXIST;
    }

    Irp->IoStatus.Status = status;
    ClassReleaseRemoveLock(DeviceObject, Irp);
    ClassCompleteRequest(DeviceObject, Irp, IO_NO_INCREMENT);
    return status;
}
Exemple #7
0
/*++////////////////////////////////////////////////////////////////////////////

ClassMinimalPowerHandler()

Routine Description:

    This routine is the minimum power handler for a storage driver.  It does
    the least amount of work possible.

--*/
NTSTATUS
NTAPI
ClassMinimalPowerHandler(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )
{
    PCOMMON_DEVICE_EXTENSION commonExtension = DeviceObject->DeviceExtension;
    PIO_STACK_LOCATION irpStack = IoGetCurrentIrpStackLocation(Irp);
    NTSTATUS status;

    ClassReleaseRemoveLock(DeviceObject, Irp);
    PoStartNextPowerIrp(Irp);

    if(commonExtension->IsFdo) {

        if (DeviceObject->Characteristics & FILE_REMOVABLE_MEDIA) {

            PFUNCTIONAL_DEVICE_EXTENSION fdoExtension = 
                DeviceObject->DeviceExtension;

            //
            // Check if the system is going to hibernate or standby.
            //
            if (irpStack->MinorFunction == IRP_MN_SET_POWER){
                PVPB vpb;
                
                switch (irpStack->Parameters.Power.ShutdownType){
                    
                    case PowerActionSleep:
                    case PowerActionHibernate:
                        //
                        // If the volume is mounted, set the verify bit so that
                        // the filesystem will be forced re-read the media
                        // after coming out of hibernation or standby.
                        //
                        vpb = ClassGetVpb(fdoExtension->DeviceObject);
                        if (vpb && (vpb->Flags & VPB_MOUNTED)){
                            SET_FLAG(fdoExtension->DeviceObject->Flags, DO_VERIFY_VOLUME);  
                        } 
                        break;
                    default:
                        break;
                }
            } 
        }

        IoCopyCurrentIrpStackLocationToNext(Irp);
        return PoCallDriver(commonExtension->LowerDeviceObject, Irp);

    } else {

        if (irpStack->MinorFunction != IRP_MN_SET_POWER &&
            irpStack->MinorFunction != IRP_MN_QUERY_POWER) {
           
            NOTHING;

        } else {

            Irp->IoStatus.Status = STATUS_SUCCESS;
            Irp->IoStatus.Information = 0;

        }
        status = Irp->IoStatus.Status;

        ClassCompleteRequest(DeviceObject, Irp, IO_NO_INCREMENT);
        return status;
    }
} // end ClassMinimalPowerHandler()
Exemple #8
0
NTSTATUS TransferPktComplete(IN PDEVICE_OBJECT NullFdo, IN PIRP Irp, IN PVOID Context)
{
    PTRANSFER_PACKET pkt = (PTRANSFER_PACKET)Context;
    PFUNCTIONAL_DEVICE_EXTENSION fdoExt = pkt->Fdo->DeviceExtension;
    PCLASS_PRIVATE_FDO_DATA fdoData = fdoExt->PrivateFdoData;
    BOOLEAN packetDone = FALSE;
    BOOLEAN idleRequest = FALSE;

    /*
     *  Put all the assertions and spew in here so we don't have to look at them.
     */
    DBGLOGRETURNPACKET(pkt);
    DBGCHECKRETURNEDPKT(pkt);
    HISTORYLOGRETURNEDPACKET(pkt);

    if (fdoData->IdlePrioritySupported == TRUE) {
        idleRequest = ClasspIsIdleRequest(pkt->OriginalIrp);
        if (idleRequest) {
            InterlockedDecrement(&fdoData->ActiveIdleIoCount);
            ASSERT(fdoData->ActiveIdleIoCount >= 0);
        } else {
            InterlockedDecrement(&fdoData->ActiveIoCount);
            ASSERT(fdoData->ActiveIoCount >= 0);
            KeQuerySystemTime(&fdoData->LastIoTime);
            fdoData->IdleTicks = 0;
        }
    }

    //
    // If partial MDL was used, unmap the pages.  When the packet is retried, the
    // MDL will be recreated.  If the packet is done, the MDL will be ready to be reused.
    //
    if (pkt->UsePartialMdl) {
        MmPrepareMdlForReuse(pkt->PartialMdl);
    }

    if (SRB_STATUS(pkt->Srb.SrbStatus) == SRB_STATUS_SUCCESS) {

        fdoData->LoggedTURFailureSinceLastIO = FALSE;

        /*
         *  The port driver should not have allocated a sense buffer
         *  if the SRB succeeded.
         */
        ASSERT(!PORT_ALLOCATED_SENSE(fdoExt, &pkt->Srb));

        /*
         *  Add this packet's transferred length to the original IRP's.
         */
        InterlockedExchangeAdd((PLONG)&pkt->OriginalIrp->IoStatus.Information,
                              (LONG)pkt->Srb.DataTransferLength);

        if ((pkt->InLowMemRetry) ||
            (pkt->DriverUsesStartIO && pkt->LowMemRetry_remainingBufLen > 0)) {
            packetDone = StepLowMemRetry(pkt);
        }
        else {
            packetDone = TRUE;
        }

    }
    else {
        /*
         *  The packet failed.  We may retry it if possible.
         */
        BOOLEAN shouldRetry;

        /*
         *  Make sure IRP status matches SRB error status (since we propagate it).
         */
        if (NT_SUCCESS(Irp->IoStatus.Status)){
            Irp->IoStatus.Status = STATUS_UNSUCCESSFUL;
        }

        /*
         *  The packet failed.
         *  So when sending the packet down we either saw either an error or STATUS_PENDING,
         *  and so we returned STATUS_PENDING for the original IRP.
         *  So now we must mark the original irp pending to match that, _regardless_ of
         *  whether we actually switch threads here by retrying.
         *  (We also have to mark the irp pending if the lower driver marked the irp pending;
         *   that is dealt with farther down).
         */
        if (pkt->CompleteOriginalIrpWhenLastPacketCompletes){
            IoMarkIrpPending(pkt->OriginalIrp);
        }

        /*
         *  Interpret the SRB error (to a meaningful IRP status)
         *  and determine if we should retry this packet.
         *  This call looks at the returned SENSE info to figure out what to do.
         */
        shouldRetry = InterpretTransferPacketError(pkt);

        /*
         *  Sometimes the port driver can allocates a new 'sense' buffer
         *  to report transfer errors, e.g. when the default sense buffer
         *  is too small.  If so, it is up to us to free it.
         *  Now that we're done interpreting the sense info, free it if appropriate.
         *  Then clear the sense buffer so it doesn't pollute future errors returned in this packet.
         */
        if (PORT_ALLOCATED_SENSE(fdoExt, &pkt->Srb)) {
            TracePrint((TRACE_LEVEL_INFORMATION, TRACE_FLAG_RW, "Freeing port-allocated sense buffer for pkt %ph.", pkt));
            FREE_PORT_ALLOCATED_SENSE_BUFFER(fdoExt, &pkt->Srb);
            pkt->Srb.SenseInfoBuffer = &pkt->SrbErrorSenseData;
            pkt->Srb.SenseInfoBufferLength = sizeof(SENSE_DATA);
        }
        else {
            ASSERT(pkt->Srb.SenseInfoBuffer == &pkt->SrbErrorSenseData);
            ASSERT(pkt->Srb.SenseInfoBufferLength <= sizeof(SENSE_DATA));
        }
        RtlZeroMemory(&pkt->SrbErrorSenseData, sizeof(SENSE_DATA));

        /*
         *  If the SRB queue is locked-up, release it.
         *  Do this after calling the error handler.
         */
        if (pkt->Srb.SrbStatus & SRB_STATUS_QUEUE_FROZEN){
            ClassReleaseQueue(pkt->Fdo);
        }

        if (NT_SUCCESS(Irp->IoStatus.Status)){
            /*
             *  The error was recovered above in the InterpretTransferPacketError() call.
             */

            ASSERT(!shouldRetry);

            /*
             *  In the case of a recovered error,
             *  add the transfer length to the original Irp as we would in the success case.
             */
            InterlockedExchangeAdd((PLONG)&pkt->OriginalIrp->IoStatus.Information,
                                  (LONG)pkt->Srb.DataTransferLength);

            if ((pkt->InLowMemRetry) ||
                (pkt->DriverUsesStartIO && pkt->LowMemRetry_remainingBufLen > 0)) {
                packetDone = StepLowMemRetry(pkt);
            }
            else {
                packetDone = TRUE;
            }
        }
        else {
            if (shouldRetry && (pkt->NumRetries > 0)){
                packetDone = RetryTransferPacket(pkt);
            }
            else if (shouldRetry && (pkt->RetryHistory != NULL)){
                // don't limit retries if class driver has custom interpretation routines
                packetDone = RetryTransferPacket(pkt);
            }
            else {
                packetDone = TRUE;
            }
        }
    }

    /*
     *  If the packet is completed, put it back in the free list.
     *  If it is the last packet servicing the original request, complete the original irp.
     */
    if (packetDone){
        LONG numPacketsRemaining;
        PIRP deferredIrp;
        PDEVICE_OBJECT Fdo = pkt->Fdo;
        UCHAR uniqueAddr;

        /*
         *  In case a remove is pending, bump the lock count so we don't get freed
         *  right after we complete the original irp.
         */
        ClassAcquireRemoveLock(Fdo, (PIRP)&uniqueAddr);


        /*
         *  The original IRP should get an error code
         *  if any one of the packets failed.
         */
        if (!NT_SUCCESS(Irp->IoStatus.Status)){
            pkt->OriginalIrp->IoStatus.Status = Irp->IoStatus.Status;

            /*
             *  If the original I/O originated in user space (i.e. it is thread-queued),
             *  and the error is user-correctable (e.g. media is missing, for removable media),
             *  alert the user.
             *  Since this is only one of possibly several packets completing for the original IRP,
             *  we may do this more than once for a single request.  That's ok; this allows
             *  us to test each returned status with IoIsErrorUserInduced().
             */
            if (IoIsErrorUserInduced(Irp->IoStatus.Status) &&
                pkt->CompleteOriginalIrpWhenLastPacketCompletes &&
                pkt->OriginalIrp->Tail.Overlay.Thread){

                IoSetHardErrorOrVerifyDevice(pkt->OriginalIrp, Fdo);
            }
        }

        /*
         *  We use a field in the original IRP to count
         *  down the transfer pieces as they complete.
         */
        numPacketsRemaining = InterlockedDecrement(
            (PLONG)&pkt->OriginalIrp->Tail.Overlay.DriverContext[0]);

        if (numPacketsRemaining > 0){
            /*
             *  More transfer pieces remain for the original request.
             *  Wait for them to complete before completing the original irp.
             */
        }
        else {

            /*
             *  All the transfer pieces are done.
             *  Complete the original irp if appropriate.
             */
            ASSERT(numPacketsRemaining == 0);
            if (pkt->CompleteOriginalIrpWhenLastPacketCompletes){

                IO_PAGING_PRIORITY priority = (TEST_FLAG(pkt->OriginalIrp->Flags, IRP_PAGING_IO)) ? IoGetPagingIoPriority(pkt->OriginalIrp) : IoPagingPriorityInvalid;
                KIRQL oldIrql;

                if (NT_SUCCESS(pkt->OriginalIrp->IoStatus.Status)){
                    ASSERT((ULONG)pkt->OriginalIrp->IoStatus.Information ==  IoGetCurrentIrpStackLocation(pkt->OriginalIrp)->Parameters.Read.Length);
                    ClasspPerfIncrementSuccessfulIo(fdoExt);
                }
                ClassReleaseRemoveLock(Fdo, pkt->OriginalIrp);

                /*
                 *  We submitted all the downward irps, including this last one, on the thread
                 *  that the OriginalIrp came in on.  So the OriginalIrp is completing on a
                 *  different thread iff this last downward irp is completing on a different thread.
                 *  If BlkCache is loaded, for example, it will often complete
                 *  requests out of the cache on the same thread, therefore not marking the downward
                 *  irp pending and not requiring us to do so here.  If the downward request is completing
                 *  on the same thread, then by not marking the OriginalIrp pending we can save an APC
                 *  and get extra perf benefit out of BlkCache.
                 *  Note that if the packet ever cycled due to retry or LowMemRetry,
                 *  we set the pending bit in those codepaths.
                 */
                if (pkt->Irp->PendingReturned){
                    IoMarkIrpPending(pkt->OriginalIrp);
                }


                ClassCompleteRequest(Fdo, pkt->OriginalIrp, IO_DISK_INCREMENT);

                //
                // Drop the count only after completing the request, to give
                // Mm some amount of time to issue its next critical request
                //

                if (priority == IoPagingPriorityHigh)
                {
                    KeAcquireSpinLock(&fdoData->SpinLock, &oldIrql);

                    if (fdoData->MaxInterleavedNormalIo < ClassMaxInterleavePerCriticalIo)
                    {
                        fdoData->MaxInterleavedNormalIo = 0;
                    }
                    else
                    {
                        fdoData->MaxInterleavedNormalIo -= ClassMaxInterleavePerCriticalIo;
                    }

                    fdoData->NumHighPriorityPagingIo--;

                    if (fdoData->NumHighPriorityPagingIo == 0)
                    {
                        LARGE_INTEGER period;

                        //
                        // Exiting throttle mode
                        //

                        KeQuerySystemTime(&fdoData->ThrottleStopTime);

                        period.QuadPart = fdoData->ThrottleStopTime.QuadPart - fdoData->ThrottleStartTime.QuadPart;
                        fdoData->LongestThrottlePeriod.QuadPart = max(fdoData->LongestThrottlePeriod.QuadPart, period.QuadPart);
                    }

                    KeReleaseSpinLock(&fdoData->SpinLock, oldIrql);
                }

                if (idleRequest) {
                    ClasspCompleteIdleRequest(fdoExt);
                }

                /*
                 *  We may have been called by one of the class drivers (e.g. cdrom)
                 *  via the legacy API ClassSplitRequest.
                 *  This is the only case for which the packet engine is called for an FDO
                 *  with a StartIo routine; in that case, we have to call IoStartNextPacket
                 *  now that the original irp has been completed.
                 */
                if (fdoExt->CommonExtension.DriverExtension->InitData.ClassStartIo) {
                    if (TEST_FLAG(pkt->Srb.SrbFlags, SRB_FLAGS_DONT_START_NEXT_PACKET)){
                        TracePrint((TRACE_LEVEL_INFORMATION, TRACE_FLAG_RW, "SRB_FLAGS_DONT_START_NEXT_PACKET should never be set here (??)"));
                    }
                    else {
                        KeRaiseIrql(DISPATCH_LEVEL, &oldIrql);
                        IoStartNextPacket(Fdo, TRUE); // yes, some IO is now cancellable
                        KeLowerIrql(oldIrql);
                    }
                }
            }
        }

        /*
         *  If the packet was synchronous, write the final result back to the issuer's status buffer
         *  and signal his event.
         */
        if (pkt->SyncEventPtr){
            KeSetEvent(pkt->SyncEventPtr, 0, FALSE);
            pkt->SyncEventPtr = NULL;
        }

        /*
         *  Free the completed packet.
         */
        pkt->UsePartialMdl = FALSE;
//        pkt->OriginalIrp = NULL;
        pkt->InLowMemRetry = FALSE;
        EnqueueFreeTransferPacket(Fdo, pkt);

        /*
         *  Now that we have freed some resources,
         *  try again to send one of the previously deferred irps.
         */
        deferredIrp = DequeueDeferredClientIrp(fdoData);
        if (deferredIrp){
            ServiceTransferRequest(Fdo, deferredIrp);
        }

        ClassReleaseRemoveLock(Fdo, (PIRP)&uniqueAddr);
    }

    return STATUS_MORE_PROCESSING_REQUIRED;
}