Sample Code
Windows Driver Samples/ CDROM Storage Class Driver/ C++/ src/ scratch.c/
/*--
Copyright (C) Microsoft Corporation. All rights reserved.
Module Name:
scratch.c
Abstract:
Functions for using common scratch buffer
Environment:
kernel mode only
Notes:
Revision History:
--*/
#include "stddef.h"
#include "string.h"
#include "ntddk.h"
#include "ntddstor.h"
#include "cdrom.h"
#include "ioctl.h"
#include "scratch.h"
#include "mmc.h"
#ifdef DEBUG_USE_WPP
#include "scratch.tmh"
#endif
// Forward declarations
EVT_WDF_REQUEST_COMPLETION_ROUTINE ScratchBuffer_ReadWriteCompletionRoutine;
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, ScratchBuffer_Deallocate)
#pragma alloc_text(PAGE, ScratchBuffer_Allocate)
#pragma alloc_text(PAGE, ScratchBuffer_SetupSrb)
#pragma alloc_text(PAGE, ScratchBuffer_ExecuteCdbEx)
#endif
_IRQL_requires_max_(APC_LEVEL)
VOID
ScratchBuffer_Deallocate(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension
)
/*++
Routine Description:
release all resources allocated for scratch.
Arguments:
DeviceExtension - device extension
Return Value:
none
--*/
{
PAGED_CODE ();
NT_ASSERT(DeviceExtension->ScratchContext.ScratchInUse == 0);
if (DeviceExtension->ScratchContext.ScratchHistory != NULL)
{
ExFreePool(DeviceExtension->ScratchContext.ScratchHistory);
DeviceExtension->ScratchContext.ScratchHistory = NULL;
}
if (DeviceExtension->ScratchContext.ScratchSense != NULL)
{
ExFreePool(DeviceExtension->ScratchContext.ScratchSense);
DeviceExtension->ScratchContext.ScratchSense = NULL;
}
if (DeviceExtension->ScratchContext.ScratchSrb != NULL)
{
ExFreePool(DeviceExtension->ScratchContext.ScratchSrb);
DeviceExtension->ScratchContext.ScratchSrb = NULL;
}
if (DeviceExtension->ScratchContext.ScratchBufferSize != 0)
{
DeviceExtension->ScratchContext.ScratchBufferSize = 0;
}
if (DeviceExtension->ScratchContext.ScratchBufferMdl != NULL)
{
IoFreeMdl(DeviceExtension->ScratchContext.ScratchBufferMdl);
DeviceExtension->ScratchContext.ScratchBufferMdl = NULL;
}
if (DeviceExtension->ScratchContext.ScratchBuffer != NULL)
{
ExFreePool(DeviceExtension->ScratchContext.ScratchBuffer);
DeviceExtension->ScratchContext.ScratchBuffer = NULL;
}
if (DeviceExtension->ScratchContext.PartialMdl != NULL)
{
IoFreeMdl(DeviceExtension->ScratchContext.PartialMdl);
DeviceExtension->ScratchContext.PartialMdl = NULL;
}
if (DeviceExtension->ScratchContext.ScratchRequest != NULL)
{
PIRP irp = WdfRequestWdmGetIrp(DeviceExtension->ScratchContext.ScratchRequest);
if (irp->MdlAddress)
{
irp->MdlAddress = NULL;
}
WdfObjectDelete(DeviceExtension->ScratchContext.ScratchRequest);
DeviceExtension->ScratchContext.ScratchRequest = NULL;
}
return;
}
_IRQL_requires_max_(APC_LEVEL)
BOOLEAN
ScratchBuffer_Allocate(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension
)
/*++
Routine Description:
allocate resources allocated for scratch.
Arguments:
DeviceExtension - device extension
Return Value:
none
--*/
{
NTSTATUS status = STATUS_SUCCESS;
PAGED_CODE ();
NT_ASSERT(DeviceExtension->ScratchContext.ScratchInUse == 0);
// quick-exit if already allocated
if ((DeviceExtension->ScratchContext.ScratchBuffer != NULL) &&
(DeviceExtension->ScratchContext.ScratchBufferMdl != NULL) &&
(DeviceExtension->ScratchContext.ScratchBufferSize != 0) &&
(DeviceExtension->ScratchContext.ScratchRequest != NULL) &&
(DeviceExtension->ScratchContext.ScratchSrb != NULL) &&
(DeviceExtension->ScratchContext.ScratchHistory != NULL) &&
(DeviceExtension->ScratchContext.PartialMdl != NULL)
)
{
return TRUE;
}
// validate max transfer already determined
NT_ASSERT(DeviceExtension->DeviceAdditionalData.MaxPageAlignedTransferBytes != 0);
// validate no partially-saved state
NT_ASSERT(DeviceExtension->ScratchContext.ScratchBuffer == NULL);
NT_ASSERT(DeviceExtension->ScratchContext.ScratchBufferMdl == NULL);
NT_ASSERT(DeviceExtension->ScratchContext.ScratchBufferSize == 0);
NT_ASSERT(DeviceExtension->ScratchContext.ScratchRequest == NULL);
NT_ASSERT(DeviceExtension->ScratchContext.PartialMdl == NULL);
// limit the scratch buffer to between 4k and 64k (so data length fits into USHORT -- req'd for many commands)
DeviceExtension->ScratchContext.ScratchBufferSize = min(DeviceExtension->DeviceAdditionalData.MaxPageAlignedTransferBytes, (64*1024));
// allocate the buffer
if (NT_SUCCESS(status))
{
DeviceExtension->ScratchContext.ScratchBuffer = ExAllocatePoolWithTag(NonPagedPoolNx,
DeviceExtension->ScratchContext.ScratchBufferSize,
CDROM_TAG_SCRATCH);
if (DeviceExtension->ScratchContext.ScratchBuffer == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
TracePrint((TRACE_LEVEL_WARNING, TRACE_FLAG_INIT,
"Failed to allocate scratch buffer of %x bytes\n",
DeviceExtension->ScratchContext.ScratchBufferSize
));
}
else if (BYTE_OFFSET(DeviceExtension->ScratchContext.ScratchBuffer) != 0)
{
status = STATUS_INTERNAL_ERROR;
TracePrint((TRACE_LEVEL_FATAL, TRACE_FLAG_INIT,
"Allocation of %x bytes non-paged pool was not "
"allocated on page boundary? STATUS_INTERNAL_ERROR\n",
DeviceExtension->ScratchContext.ScratchBufferSize
));
}
}
// allocate the MDL
if (NT_SUCCESS(status))
{
DeviceExtension->ScratchContext.ScratchBufferMdl = IoAllocateMdl(DeviceExtension->ScratchContext.ScratchBuffer,
DeviceExtension->ScratchContext.ScratchBufferSize,
FALSE, FALSE, NULL);
if (DeviceExtension->ScratchContext.ScratchBufferMdl == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
TracePrint((TRACE_LEVEL_WARNING, TRACE_FLAG_INIT,
"Failed to allocate MDL for %x byte buffer\n",
DeviceExtension->ScratchContext.ScratchBufferSize
));
}
else
{
MmBuildMdlForNonPagedPool(DeviceExtension->ScratchContext.ScratchBufferMdl);
}
}
// create the request
if (NT_SUCCESS(status))
{
WDF_OBJECT_ATTRIBUTES attributes;
WDF_OBJECT_ATTRIBUTES_INIT_CONTEXT_TYPE(&attributes,
CDROM_REQUEST_CONTEXT);
status = WdfRequestCreate(&attributes,
DeviceExtension->IoTarget,
&DeviceExtension->ScratchContext.ScratchRequest);
if ((!NT_SUCCESS(status)) ||
(DeviceExtension->ScratchContext.ScratchRequest == NULL))
{
status = STATUS_INSUFFICIENT_RESOURCES;
TracePrint((TRACE_LEVEL_WARNING, TRACE_FLAG_INIT,
"Failed to allocate scratch MDL \n"));
}
}
// allocate the srb
if (NT_SUCCESS(status))
{
DeviceExtension->ScratchContext.ScratchSrb = ExAllocatePoolWithTag(NonPagedPoolNx,
sizeof(SCSI_REQUEST_BLOCK),
CDROM_TAG_SCRATCH);
if (DeviceExtension->ScratchContext.ScratchSrb == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
TracePrint((TRACE_LEVEL_WARNING, TRACE_FLAG_INIT,
"Failed to allocate scratch SRB\n"));
}
}
// allocate the sense buffer
if (NT_SUCCESS(status))
{
DeviceExtension->ScratchContext.ScratchSense = ExAllocatePoolWithTag(NonPagedPoolNx,
sizeof(SENSE_DATA),
CDROM_TAG_SCRATCH);
if (DeviceExtension->ScratchContext.ScratchSense == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
TracePrint((TRACE_LEVEL_WARNING, TRACE_FLAG_INIT,
"Failed to allocate scratch sense data\n"
));
}
}
// allocate the SRB history data
if (NT_SUCCESS(status))
{
size_t allocationSize = sizeof(SRB_HISTORY) - sizeof(SRB_HISTORY_ITEM);
allocationSize += 20 * sizeof(SRB_HISTORY_ITEM);
DeviceExtension->ScratchContext.ScratchHistory = ExAllocatePoolWithTag(NonPagedPoolNx,
allocationSize,
CDROM_TAG_SCRATCH);
if (DeviceExtension->ScratchContext.ScratchHistory == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
TracePrint((TRACE_LEVEL_WARNING, TRACE_FLAG_INIT,
"Failed to allocate scratch history buffer\n"
));
}
else
{
// must be initialized here...
RtlZeroMemory(DeviceExtension->ScratchContext.ScratchHistory, allocationSize);
DeviceExtension->ScratchContext.ScratchHistory->TotalHistoryCount = 20;
}
}
// allocate the MDL
if (NT_SUCCESS(status))
{
ULONG transferLength = 0;
status = RtlULongAdd(DeviceExtension->DeviceAdditionalData.MaxPageAlignedTransferBytes, PAGE_SIZE, &transferLength);
if (NT_SUCCESS(status))
{
DeviceExtension->ScratchContext.PartialMdlIsBuilt = FALSE;
DeviceExtension->ScratchContext.PartialMdl = IoAllocateMdl(NULL,
transferLength,
FALSE,
FALSE,
NULL);
if (DeviceExtension->ScratchContext.PartialMdl == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
TracePrint((TRACE_LEVEL_WARNING, TRACE_FLAG_INIT,
"Failed to allocate MDL for %x byte buffer\n",
DeviceExtension->ScratchContext.ScratchBufferSize
));
}
else
{
NT_ASSERT(DeviceExtension->ScratchContext.PartialMdl->Size >=
(CSHORT)(sizeof(MDL) + BYTES_TO_PAGES(DeviceExtension->DeviceAdditionalData.MaxPageAlignedTransferBytes) * sizeof(PFN_NUMBER)));
}
}
else
{
status = STATUS_INTEGER_OVERFLOW;
}
}
// cleanup on failure
if (!NT_SUCCESS(status))
{
ScratchBuffer_Deallocate(DeviceExtension);
}
return NT_SUCCESS(status);
}
VOID
ScratchBuffer_ResetItems(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_ BOOLEAN ResetRequestHistory
)
/*++
Routine Description:
reset scratch items for reuse.
Arguments:
DeviceExtension - device extension
ResetRequestHistory - reset history fields or not
Return Value:
none
--*/
{
NTSTATUS status = STATUS_SUCCESS;
WDF_REQUEST_REUSE_PARAMS reuseParams;
PIRP irp = NULL;
NT_ASSERT(DeviceExtension->ScratchContext.ScratchHistory != NULL);
NT_ASSERT(DeviceExtension->ScratchContext.ScratchSense != NULL);
NT_ASSERT(DeviceExtension->ScratchContext.ScratchSrb != NULL);
NT_ASSERT(DeviceExtension->ScratchContext.ScratchRequest != NULL);
NT_ASSERT(DeviceExtension->ScratchContext.ScratchBufferSize != 0);
NT_ASSERT(DeviceExtension->ScratchContext.ScratchBuffer != NULL);
NT_ASSERT(DeviceExtension->ScratchContext.ScratchBufferMdl != NULL);
NT_ASSERT(DeviceExtension->ScratchContext.ScratchInUse != 0);
irp = WdfRequestWdmGetIrp(DeviceExtension->ScratchContext.ScratchRequest);
if (ResetRequestHistory)
{
PSRB_HISTORY history = DeviceExtension->ScratchContext.ScratchHistory;
RtlZeroMemory(history->History, sizeof(SRB_HISTORY_ITEM) * history->TotalHistoryCount);
history->ClassDriverUse[0] = 0;
history->ClassDriverUse[1] = 0;
history->ClassDriverUse[2] = 0;
history->ClassDriverUse[3] = 0;
history->UsedHistoryCount = 0;
}
// re-use the KMDF request object
// deassign the MdlAddress, this is the value we assign explicitly.
// this is to prevent WdfRequestReuse to release the Mdl unexpectly.
if (irp->MdlAddress)
{
irp->MdlAddress = NULL;
}
WDF_REQUEST_REUSE_PARAMS_INIT(&reuseParams, WDF_REQUEST_REUSE_NO_FLAGS, STATUS_NOT_SUPPORTED);
status = WdfRequestReuse(DeviceExtension->ScratchContext.ScratchRequest, &reuseParams);
// WDF request to format the request befor sending it
if (NT_SUCCESS(status))
{
// clean up completion routine.
WdfRequestSetCompletionRoutine(DeviceExtension->ScratchContext.ScratchRequest, NULL, NULL);
status = WdfIoTargetFormatRequestForInternalIoctlOthers(DeviceExtension->IoTarget,
DeviceExtension->ScratchContext.ScratchRequest,
IOCTL_SCSI_EXECUTE_IN,
NULL, NULL,
NULL, NULL,
NULL, NULL);
if (!NT_SUCCESS(status))
{
TracePrint((TRACE_LEVEL_ERROR, TRACE_FLAG_GENERAL,
"ScratchBuffer_ResetItems: WdfIoTargetFormatRequestForInternalIoctlOthers failed, %!STATUS!\n",
status));
}
}
RtlZeroMemory(DeviceExtension->ScratchContext.ScratchSense, sizeof(SENSE_DATA));
RtlZeroMemory(DeviceExtension->ScratchContext.ScratchSrb, sizeof(SCSI_REQUEST_BLOCK));
return;
}
NTSTATUS
ScratchBuffer_PerformNextReadWrite(
_In_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_ BOOLEAN FirstTry
)
/*++
Routine Description:
This function asynchronously sends the next read/write SRB down the stack.
Arguments:
DeviceExtension - Device extension
Return Value:
none
--*/
{
PCDROM_SCRATCH_READ_WRITE_CONTEXT readWriteContext = &DeviceExtension->ScratchContext.ScratchReadWriteContext;
PCDROM_REQUEST_CONTEXT requestContext = RequestGetContext(DeviceExtension->ScratchContext.ScratchRequest);
WDFREQUEST originalRequest = requestContext->OriginalRequest;
NTSTATUS status = STATUS_SUCCESS;
ULONG transferSize;
BOOLEAN usePartialMdl;
transferSize = min((readWriteContext->EntireXferLen - readWriteContext->TransferedBytes), readWriteContext->MaxLength);
if (FirstTry)
{
DeviceExtension->ScratchContext.NumRetries = 0;
}
ScratchBuffer_ResetItems(DeviceExtension, FALSE);
usePartialMdl = (readWriteContext->PacketsCount > 1 || readWriteContext->TransferedBytes > 0);
ScratchBuffer_SetupReadWriteSrb(DeviceExtension,
originalRequest,
readWriteContext->StartingOffset,
transferSize,
readWriteContext->DataBuffer,
readWriteContext->IsRead,
usePartialMdl
);
WdfRequestSetCompletionRoutine(DeviceExtension->ScratchContext.ScratchRequest,
ScratchBuffer_ReadWriteCompletionRoutine, DeviceExtension);
status = ScratchBuffer_SendSrb(DeviceExtension, FALSE, (FirstTry ? &readWriteContext->SrbHistoryItem : NULL));
return status;
}
VOID
ScratchBuffer_ReadWriteTimerRoutine(
struct _KDPC *Dpc,
PVOID DeferredContext,
PVOID SystemArgument1,
PVOID SystemArgument2
)
/*++
Routine Description:
Timer routine for retrying read and write requests.
Arguments:
Timer - WDF timer
Return Value:
none
--*/
{
PCDROM_DEVICE_EXTENSION deviceExtension = NULL;
PCDROM_SCRATCH_READ_WRITE_CONTEXT readWriteContext = NULL;
WDFREQUEST originalRequest = NULL;
PCDROM_REQUEST_CONTEXT requestContext = NULL;
NTSTATUS status = STATUS_SUCCESS;
KIRQL oldIrql;
UNREFERENCED_PARAMETER(Dpc);
UNREFERENCED_PARAMETER(SystemArgument1);
UNREFERENCED_PARAMETER(SystemArgument2);
if (DeferredContext == NULL)
{
// This is impossible, but definition of KDEFERRED_ROUTINE allows optional argument,
// and thus OACR will complain.
return;
}
originalRequest = (WDFREQUEST) DeferredContext;
requestContext = RequestGetContext(originalRequest);
KeAcquireSpinLock(&requestContext->ReadWriteCancelSpinLock, &oldIrql);
if (!requestContext->ReadWriteIsCompleted)
{
// As the first step, unregister the cancellation routine
status = WdfRequestUnmarkCancelable(originalRequest);
}
else
{
status = STATUS_CANCELLED;
}
KeReleaseSpinLock(&requestContext->ReadWriteCancelSpinLock, oldIrql);
if (status != STATUS_CANCELLED)
{
deviceExtension = requestContext->DeviceExtension;
readWriteContext = &deviceExtension->ScratchContext.ScratchReadWriteContext;
// We use timer only for retries, that's why the second parameter is always FALSE
status = ScratchBuffer_PerformNextReadWrite(deviceExtension, FALSE);
if (!NT_SUCCESS(status))
{
ScratchBuffer_EndUse(deviceExtension);
RequestCompletion(deviceExtension, originalRequest, status, readWriteContext->TransferedBytes);
}
}
//
// Drop the extra reference
//
WdfObjectDereference(originalRequest);
}
EVT_WDF_REQUEST_CANCEL ScratchBuffer_ReadWriteEvtRequestCancel;
VOID
ScratchBuffer_ReadWriteEvtRequestCancel(
_In_ WDFREQUEST Request
)
/*++
Routine Description:
Cancels a request waiting for the read/write timer to expire. This function does not
support cancellation of requests that have already been sent down.
Arguments:
Request - WDF request
Return Value:
none
--*/
{
PCDROM_REQUEST_CONTEXT requestContext = RequestGetContext(Request);
PCDROM_DEVICE_EXTENSION deviceExtension = requestContext->DeviceExtension;
PCDROM_SCRATCH_READ_WRITE_CONTEXT readWriteContext = &deviceExtension->ScratchContext.ScratchReadWriteContext;
KIRQL oldIrql;
KeAcquireSpinLock(&requestContext->ReadWriteCancelSpinLock, &oldIrql);
if (KeCancelTimer(&requestContext->ReadWriteTimer))
{
//
// Timer is canceled, we own the request. Drop the reference we took before
// queueing the timer.
//
WdfObjectDereference(Request);
}
else
{
//
// Timer will run and drop the reference but it won't complete the request
// because we set IsCompleted to TRUE
//
}
requestContext->ReadWriteIsCompleted = TRUE;
KeReleaseSpinLock(&requestContext->ReadWriteCancelSpinLock, oldIrql);
ScratchBuffer_EndUse(deviceExtension);
// If WdfTimerStop returned TRUE, it means this request was scheduled for a retry
// and the retry has not happened yet. We just need to cancel it and release the scratch buffer.
RequestCompletion(deviceExtension, Request, STATUS_CANCELLED, readWriteContext->TransferedBytes);
}
VOID
ScratchBuffer_ReadWriteCompletionRoutine(
_In_ WDFREQUEST Request,
_In_ WDFIOTARGET Target,
_In_ PWDF_REQUEST_COMPLETION_PARAMS Params,
_In_ WDFCONTEXT Context
)
/*++
Routine Description:
Read/write request completion routine.
Arguments:
Request - WDF request
Target - The IO target the request was completed by.
Params - the request completion parameters
Context - context
Return Value:
none
--*/
{
PCDROM_DEVICE_EXTENSION deviceExtension = (PCDROM_DEVICE_EXTENSION) Context;
PCDROM_SCRATCH_READ_WRITE_CONTEXT readWriteContext = &deviceExtension->ScratchContext.ScratchReadWriteContext;
NTSTATUS status = STATUS_SUCCESS;
PCDROM_REQUEST_CONTEXT requestContext = RequestGetContext(deviceExtension->ScratchContext.ScratchRequest);
WDFREQUEST originalRequest = requestContext->OriginalRequest;
if (!NT_SUCCESS(WdfRequestGetStatus(Request)))
{
TracePrint((TRACE_LEVEL_WARNING, TRACE_FLAG_INIT,
"WdfRequestSend: %lx\n",
WdfRequestGetStatus(Request)
));
}
UNREFERENCED_PARAMETER(Params);
UNREFERENCED_PARAMETER(Target);
// We are not calling ScratchBuffer_BeginUse / ScratchBuffer_EndUse in this function, because we already own
// the scratch buffer if this function is being called.
if ((deviceExtension->ScratchContext.ScratchSrb->SrbStatus == SRB_STATUS_ABORTED) &&
(deviceExtension->ScratchContext.ScratchSrb->InternalStatus == STATUS_CANCELLED))
{
// The request has been cancelled, just need to complete it
}
else if (SRB_STATUS(deviceExtension->ScratchContext.ScratchSrb->SrbStatus) != SRB_STATUS_SUCCESS)
{
// The SCSI command that we sent down has failed, retry it if necessary
BOOLEAN shouldRetry = TRUE;
LONGLONG retryIn100nsUnits = 0;
shouldRetry = RequestSenseInfoInterpretForScratchBuffer(deviceExtension,
deviceExtension->ScratchContext.NumRetries,
&status,
&retryIn100nsUnits);
if (shouldRetry)
{
deviceExtension->ScratchContext.NumRetries++;
if (retryIn100nsUnits == 0)
{
// We take a shortcut here by calling ScratchBuffer_PerformNextReadWrite directly:
// this helps to avoid unnecessary context switch.
status = ScratchBuffer_PerformNextReadWrite(deviceExtension, FALSE);
if (NT_SUCCESS(status))
{
// We're not done with the request yet, no need to complete it now
return;
}
}
else
{
PCDROM_REQUEST_CONTEXT originalRequestContext = RequestGetContext(originalRequest);
KIRQL oldIrql;
//
// Initialize the spin lock and timer local to the original request.
//
if (!originalRequestContext->ReadWriteRetryInitialized)
{
KeInitializeSpinLock(&originalRequestContext->ReadWriteCancelSpinLock);
KeInitializeTimer(&originalRequestContext->ReadWriteTimer);
KeInitializeDpc(&originalRequestContext->ReadWriteDpc, ScratchBuffer_ReadWriteTimerRoutine, originalRequest);
originalRequestContext->ReadWriteRetryInitialized = TRUE;
}
KeAcquireSpinLock(&requestContext->ReadWriteCancelSpinLock, &oldIrql);
status = WdfRequestMarkCancelableEx(originalRequest, ScratchBuffer_ReadWriteEvtRequestCancel);
if (status == STATUS_CANCELLED)
{
requestContext->ReadWriteIsCompleted = TRUE;
KeReleaseSpinLock(&requestContext->ReadWriteCancelSpinLock, oldIrql);
}
else
{
LARGE_INTEGER t;
t.QuadPart = -retryIn100nsUnits;
WdfObjectReference(originalRequest);
// Use negative time to indicate that we want a relative delay
KeSetTimer(&originalRequestContext->ReadWriteTimer,
t,
&originalRequestContext->ReadWriteDpc
);
KeReleaseSpinLock(&requestContext->ReadWriteCancelSpinLock, oldIrql);
return;
}
}
}
}
else
{
// The SCSI command has succeeded
readWriteContext->DataBuffer += deviceExtension->ScratchContext.ScratchSrb->DataTransferLength;
readWriteContext->StartingOffset.QuadPart += deviceExtension->ScratchContext.ScratchSrb->DataTransferLength;
readWriteContext->TransferedBytes += deviceExtension->ScratchContext.ScratchSrb->DataTransferLength;
readWriteContext->PacketsCount--;
// Update the SRB history item
if (readWriteContext->SrbHistoryItem)
{
ULONG senseSize;
// Query the tick count and store in the history
KeQueryTickCount(&readWriteContext->SrbHistoryItem->TickCountCompleted);
// Copy the SRB Status...
readWriteContext->SrbHistoryItem->SrbStatus = deviceExtension->ScratchContext.ScratchSrb->SrbStatus;
// Determine the amount of valid sense data
if (deviceExtension->ScratchContext.ScratchSrb->SenseInfoBufferLength >=
RTL_SIZEOF_THROUGH_FIELD(SENSE_DATA, AdditionalSenseLength))
{
PSENSE_DATA sense = (PSENSE_DATA)deviceExtension->ScratchContext.ScratchSrb->SenseInfoBuffer;
senseSize = RTL_SIZEOF_THROUGH_FIELD(SENSE_DATA, AdditionalSenseLength) +
sense->AdditionalSenseLength;
senseSize = min(senseSize, sizeof(SENSE_DATA));
}
else
{
senseSize = deviceExtension->ScratchContext.ScratchSrb->SenseInfoBufferLength;
}
// Normalize the sense data copy in the history
RtlZeroMemory(&(readWriteContext->SrbHistoryItem->NormalizedSenseData), sizeof(SENSE_DATA));
RtlCopyMemory(&(readWriteContext->SrbHistoryItem->NormalizedSenseData),
deviceExtension->ScratchContext.ScratchSrb->SenseInfoBuffer, senseSize);
}
// Check whether we need to send more SCSI commands to complete the request
if (readWriteContext->PacketsCount > 0)
{
status = ScratchBuffer_PerformNextReadWrite(deviceExtension, TRUE);
if (NT_SUCCESS(status))
{
// We're not done with the request yet, no need to complete it now
return;
}
}
}
ScratchBuffer_EndUse(deviceExtension);
RequestCompletion(deviceExtension, originalRequest, status, readWriteContext->TransferedBytes);
}
_IRQL_requires_max_(APC_LEVEL)
VOID
ScratchBuffer_SetupSrb(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_opt_ WDFREQUEST OriginalRequest,
_In_ ULONG MaximumTransferLength,
_In_ BOOLEAN GetDataFromDevice
)
/*++
Routine Description:
setup scratch SRB for sending out.
Arguments:
DeviceExtension - device extension
OriginalRequest - original request delivered by WDF
MaximumTransferLength - transfer length
GetDataFromDevice - TRUE (get data from device); FALSE (send data to device)
Return Value:
none
--*/
{
WDFREQUEST request = DeviceExtension->ScratchContext.ScratchRequest;
PIRP irp = WdfRequestWdmGetIrp(request);
PSCSI_REQUEST_BLOCK srb = DeviceExtension->ScratchContext.ScratchSrb;
PIO_STACK_LOCATION irpStack = NULL;
PCDROM_REQUEST_CONTEXT requestContext = RequestGetContext(request);
PAGED_CODE ();
requestContext->OriginalRequest = OriginalRequest;
// set to use the full scratch buffer via the scratch SRB
irpStack = IoGetNextIrpStackLocation(irp);
irpStack->MajorFunction = IRP_MJ_SCSI;
if (MaximumTransferLength == 0)
{
irpStack->Parameters.DeviceIoControl.IoControlCode = IOCTL_SCSI_EXECUTE_NONE;
}
else if (GetDataFromDevice)
{
irpStack->Parameters.DeviceIoControl.IoControlCode = IOCTL_SCSI_EXECUTE_IN;
}
else
{
irpStack->Parameters.DeviceIoControl.IoControlCode = IOCTL_SCSI_EXECUTE_OUT;
}
irpStack->Parameters.Scsi.Srb = srb;
if (MaximumTransferLength > 0)
{
// the Irp must show the MDL's address for the transfer
irp->MdlAddress = DeviceExtension->ScratchContext.ScratchBufferMdl;
srb->DataBuffer = DeviceExtension->ScratchContext.ScratchBuffer;
}
// prepare the SRB with default values
srb->Length = SCSI_REQUEST_BLOCK_SIZE;
srb->Function = SRB_FUNCTION_EXECUTE_SCSI;
srb->QueueAction = SRB_SIMPLE_TAG_REQUEST;
srb->SrbStatus = 0;
srb->ScsiStatus = 0;
srb->NextSrb = NULL;
srb->OriginalRequest = irp;
srb->SenseInfoBufferLength = SENSE_BUFFER_SIZE;
srb->SenseInfoBuffer = DeviceExtension->ScratchContext.ScratchSense;
srb->CdbLength = 16; // to cause failures if not set correctly -- CD devices limited to 12 bytes for now...
srb->DataTransferLength = min(DeviceExtension->ScratchContext.ScratchBufferSize, MaximumTransferLength);
srb->TimeOutValue = DeviceExtension->TimeOutValue;
srb->SrbFlags = DeviceExtension->SrbFlags;
SET_FLAG(srb->SrbFlags, SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
SET_FLAG(srb->SrbFlags, SRB_FLAGS_NO_QUEUE_FREEZE);
if (MaximumTransferLength == 0)
{
SET_FLAG(srb->SrbFlags, SRB_FLAGS_NO_DATA_TRANSFER);
}
else if (GetDataFromDevice)
{
SET_FLAG(srb->SrbFlags, SRB_FLAGS_DATA_IN);
}
else
{
SET_FLAG(srb->SrbFlags, SRB_FLAGS_DATA_OUT);
}
}
NTSTATUS
ScratchBuffer_SendSrb(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_ BOOLEAN SynchronousSrb,
_When_(SynchronousSrb, _Pre_null_)
_When_(!SynchronousSrb, _In_opt_)
PSRB_HISTORY_ITEM *SrbHistoryItem
)
/*++
Routine Description:
Send the command from the scratch SRB to lower driver and retry if necessary.
Arguments:
DeviceExtension - device extension
SynchronousSrb - indicates whether the SRB needs to be sent synchronously or nor
SrbHistoryItem - storage for SRB history item, if this is an asynchronous request
Return Value:
none
--*/
{
NTSTATUS status = STATUS_SUCCESS;
PSCSI_REQUEST_BLOCK srb = DeviceExtension->ScratchContext.ScratchSrb;
PSRB_HISTORY history = DeviceExtension->ScratchContext.ScratchHistory;
PSRB_HISTORY_ITEM item = NULL;
BOOLEAN requestCancelled = FALSE;
srb->InternalStatus = 0;
srb->SrbStatus = 0;
// allocate/update history pre-command, if it is a synchronous request or we were supplied
// with a storage for the history item
if (SynchronousSrb || SrbHistoryItem != NULL)
{
// sending a packet implies a new history unit is to be used.
NT_ASSERT( history->UsedHistoryCount <= history->TotalHistoryCount );
// if already all used up, remove at least one history unit
if (history->UsedHistoryCount == history->TotalHistoryCount )
{
CompressSrbHistoryData(history);
NT_ASSERT( history->UsedHistoryCount < history->TotalHistoryCount );
}
// thus, since we are about to increment the count, it must now be less...
NT_ASSERT( history->UsedHistoryCount < history->TotalHistoryCount );
// increment the number of history units in use
history->UsedHistoryCount++;
// determine index to use
item = &( history->History[ history->UsedHistoryCount-1 ] );
if (SrbHistoryItem != NULL)
{
*SrbHistoryItem = item;
}
// zero out the history item
RtlZeroMemory(item, sizeof(SRB_HISTORY_ITEM));
// Query the tick count and store in the history
KeQueryTickCount(&item->TickCountSent);
}
// get cancellation status;
{
PCDROM_REQUEST_CONTEXT requestContext = RequestGetContext(DeviceExtension->ScratchContext.ScratchRequest);
if (requestContext->OriginalRequest != NULL)
{
requestCancelled = WdfRequestIsCanceled(requestContext->OriginalRequest);
}
}
if (!requestCancelled)
{
status = RequestSend(DeviceExtension,
DeviceExtension->ScratchContext.ScratchRequest,
DeviceExtension->IoTarget,
SynchronousSrb ? WDF_REQUEST_SEND_OPTION_SYNCHRONOUS : 0,
NULL);
// If this is a synchronous request, update the history item immediately, including "normalized" sense data
if (SynchronousSrb)
{
ULONG senseSize;
// Query the tick count and store in the history
KeQueryTickCount(&item->TickCountCompleted);
// Copy the SRB Status
item->SrbStatus = srb->SrbStatus;
// Determine the amount of valid sense data
if (srb->SenseInfoBufferLength >= RTL_SIZEOF_THROUGH_FIELD(SENSE_DATA, AdditionalSenseLength))
{
PSENSE_DATA sense = (PSENSE_DATA)srb->SenseInfoBuffer;
senseSize = RTL_SIZEOF_THROUGH_FIELD(SENSE_DATA, AdditionalSenseLength) +
sense->AdditionalSenseLength;
senseSize = min(senseSize, sizeof(SENSE_DATA));
}
else
{
senseSize = srb->SenseInfoBufferLength;
}
// Normalize the sense data copy in the history
RtlZeroMemory(&(item->NormalizedSenseData), sizeof(SENSE_DATA));
RtlCopyMemory(&(item->NormalizedSenseData), srb->SenseInfoBuffer, senseSize);
}
}
else
{
DeviceExtension->ScratchContext.ScratchSrb->SrbStatus = SRB_STATUS_ABORTED;
DeviceExtension->ScratchContext.ScratchSrb->InternalStatus = (ULONG)STATUS_CANCELLED;
status = STATUS_CANCELLED;
}
return status;
}
VOID
CompressSrbHistoryData(
_Inout_ PSRB_HISTORY RequestHistory
)
/*++
Routine Description:
compress the SRB history data.
Arguments:
RequestHistory - SRB history data
Return Value:
RequestHistory - compressed history data
--*/
{
ULONG i;
NT_ASSERT( RequestHistory->UsedHistoryCount == RequestHistory->TotalHistoryCount );
ValidateSrbHistoryDataPresumptions(RequestHistory);
for (i=0; i < RequestHistory->UsedHistoryCount; i++)
{
// for each item...
PSRB_HISTORY_ITEM toMatch = &( RequestHistory->History[i] );
// hint: read const qualifiers backwards. i.e. srbstatus is a const UCHAR
// so, "UCHAR const * const x" is read "x is a const pointer to a const UCHAR"
// unfortunately, "const UCHAR" is equivalent to "UCHAR const", which causes
// people no end of confusion due to its widespread use.
UCHAR const srbStatus = toMatch->SrbStatus;
UCHAR const sense = toMatch->NormalizedSenseData.SenseKey;
UCHAR const asc = toMatch->NormalizedSenseData.AdditionalSenseCode;
UCHAR const ascq = toMatch->NormalizedSenseData.AdditionalSenseCodeQualifier;
ULONG j;
// see if there are any at higher indices with identical Sense/ASC/ASCQ
for (j = i+1; (toMatch->ClassDriverUse != 0xFF) && (j < RequestHistory->UsedHistoryCount); j++)
{
PSRB_HISTORY_ITEM found = &( RequestHistory->History[j] );
// close enough match?
if ((srbStatus == found->SrbStatus) &&
(sense == found->NormalizedSenseData.SenseKey) &&
(asc == found->NormalizedSenseData.AdditionalSenseCode) &&
(ascq == found->NormalizedSenseData.AdditionalSenseCodeQualifier)) {
// add the fields to keep reasonable track of delay times.
if (toMatch->MillisecondsDelayOnRetry + found->MillisecondsDelayOnRetry < toMatch->MillisecondsDelayOnRetry) {
toMatch->MillisecondsDelayOnRetry = MAXULONG;
} else {
toMatch->MillisecondsDelayOnRetry += found->MillisecondsDelayOnRetry;
}
// this found item cannot contain any compressed entries because
// the first entry with a given set of sense/asc/ascq will always
// either be full (0xFF) or be the only partially-full entry with
// that sense/asc/ascq.
NT_ASSERT(found->ClassDriverUse == 0);
// add the counts so we still know how many retries total
toMatch->ClassDriverUse++;
// if not the last entry, need to move later entries earlier in the array
if (j != RequestHistory->UsedHistoryCount-1) {
// how many entries remain?
SIZE_T remainingBytes = RequestHistory->UsedHistoryCount - 1 - j;
remainingBytes *= sizeof(SRB_HISTORY_ITEM);
// note that MOVE is required due to overlapping entries
RtlMoveMemory(found, found+1, remainingBytes);
// Finally, decrement the number of used history count and
// decrement j to rescan the current location again
--RequestHistory->UsedHistoryCount;
--j;
} // end moving of array elements around
} // end of close enough match
} // end j loop
} // end i loop
// unable to compress duplicate sense/asc/ascq, so just lose the most recent data
if (RequestHistory->UsedHistoryCount == RequestHistory->TotalHistoryCount)
{
PSRB_HISTORY_ITEM item = &( RequestHistory->History[ RequestHistory->TotalHistoryCount-1 ] );
RequestHistory->ClassDriverUse[0] += item->ClassDriverUse; // how many did we "lose"?
RequestHistory->UsedHistoryCount--;
}
// finally, zero any that are no longer in use
NT_ASSERT( RequestHistory->UsedHistoryCount != RequestHistory->TotalHistoryCount);
{
SIZE_T bytesToZero = RequestHistory->TotalHistoryCount - RequestHistory->UsedHistoryCount;
bytesToZero *= sizeof(SRB_HISTORY_ITEM);
RtlZeroMemory(&(RequestHistory->History[RequestHistory->UsedHistoryCount]), bytesToZero);
}
ValidateSrbHistoryDataPresumptions(RequestHistory);
return;
}
VOID
ValidateSrbHistoryDataPresumptions(
_In_ SRB_HISTORY const * RequestHistory
)
{
#if DBG
// validate that all fully-compressed items are before any non-fully-compressed items of any particular sense/asc/ascq
// validate that there is at most one partially-compressed item of any particular sense/asc/ascq
// validate that all items of any particular sense/asc/ascq that are uncompressed are at the end
// THUS: A(255) A(255) A( 40) A( 0) A( 0) is legal for all types with A as sense/asc/ascq
// A(0) B(255) A( 0) B( 17) B( 0) is also legal because A/B are different types of error
ULONG i;
for (i = 0; i < RequestHistory->UsedHistoryCount; i++)
{
SRB_HISTORY_ITEM const * toMatch = &( RequestHistory->History[i] );
UCHAR const srbStatus = toMatch->SrbStatus;
UCHAR const sense = toMatch->NormalizedSenseData.SenseKey;
UCHAR const asc = toMatch->NormalizedSenseData.AdditionalSenseCode;
UCHAR const ascq = toMatch->NormalizedSenseData.AdditionalSenseCodeQualifier;
ULONG j;
BOOLEAN foundPartiallyCompressedItem =
(toMatch->ClassDriverUse != 0) &&
(toMatch->ClassDriverUse != 0xFF) ;
BOOLEAN foundUncompressedItem =
(toMatch->ClassDriverUse == 0) ;
for (j = i+1; j < RequestHistory->UsedHistoryCount; j++)
{
SRB_HISTORY_ITEM const * found = &( RequestHistory->History[j] );
if ((srbStatus == found->SrbStatus) &&
(sense == found->NormalizedSenseData.SenseKey) &&
(asc == found->NormalizedSenseData.AdditionalSenseCode) &&
(ascq == found->NormalizedSenseData.AdditionalSenseCodeQualifier)
)
{
// found a matching type, so validate ordering rules
if (foundUncompressedItem && (found->ClassDriverUse != 0))
{
DbgPrintEx(DPFLTR_CDROM_ID, DPFLTR_ERROR_LEVEL,
"History data has compressed history following uncompressed history "
"for srbstatus/sense/asc/ascq of %02x/%02x/%02x/%02x at indices %d (%08x) and %d (%08x)\n",
srbStatus, sense, asc, ascq,
i,i, j,j
);
NT_ASSERT(FALSE);
}
else if (foundPartiallyCompressedItem && (found->ClassDriverUse == 0xFF))
{
DbgPrintEx(DPFLTR_CDROM_ID, DPFLTR_ERROR_LEVEL,
"History data has fully compressed history following partially compressed history "
"for srbstatus/sense/asc/ascq of %02x/%02x/%02x/%02x at indices %d (%08x) and %d (%08x)\n",
srbStatus, sense, asc, ascq,
i,i, j,j
);
NT_ASSERT(FALSE);
}
// update if we have now found partially compressed and/or uncompressed items
if (found->ClassDriverUse == 0)
{
foundUncompressedItem = TRUE;
}
else if (found->ClassDriverUse != 0xFF)
{
foundPartiallyCompressedItem = TRUE;
}
} // end match of (toMatch,found)
} // end loop j
} // end loop i
#else
UNREFERENCED_PARAMETER(RequestHistory);
#endif
return;
}
VOID
ScratchBuffer_SetupReadWriteSrb(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_ WDFREQUEST OriginalRequest,
_In_ LARGE_INTEGER StartingOffset,
_In_ ULONG RequiredLength,
_Inout_updates_bytes_(RequiredLength) UCHAR* DataBuffer,
_In_ BOOLEAN IsReadRequest,
_In_ BOOLEAN UsePartialMdl
)
/*++
Routine Description:
setup SRB for read/write request.
Arguments:
DeviceExtension - device extension
OriginalRequest - read/write request
StartingOffset - read/write starting offset
DataBuffer - buffer for read/write
IsReadRequest - TRUE (read); FALSE (write)
Return Value:
none
--*/
{
//NOTE: R/W request not use the ScratchBuffer, instead, it uses the buffer associated with IRP.
PSCSI_REQUEST_BLOCK srb = DeviceExtension->ScratchContext.ScratchSrb;
PCDB cdb = (PCDB)srb->Cdb;
LARGE_INTEGER logicalBlockAddr;
ULONG numTransferBlocks;
PIRP originalIrp = WdfRequestWdmGetIrp(OriginalRequest);
PIRP irp = WdfRequestWdmGetIrp(DeviceExtension->ScratchContext.ScratchRequest);
PIO_STACK_LOCATION irpStack = NULL;
PCDROM_REQUEST_CONTEXT requestContext = RequestGetContext(DeviceExtension->ScratchContext.ScratchRequest);
requestContext->OriginalRequest = OriginalRequest;
logicalBlockAddr.QuadPart = Int64ShrlMod32(StartingOffset.QuadPart, DeviceExtension->SectorShift);
numTransferBlocks = RequiredLength >> DeviceExtension->SectorShift;
// set to use the full scratch buffer via the scratch SRB
irpStack = IoGetNextIrpStackLocation(irp);
irpStack->MajorFunction = IRP_MJ_SCSI;
if (IsReadRequest)
{
irpStack->Parameters.DeviceIoControl.IoControlCode = IOCTL_SCSI_EXECUTE_IN;
}
else
{
irpStack->Parameters.DeviceIoControl.IoControlCode = IOCTL_SCSI_EXECUTE_OUT;
}
irpStack->Parameters.Scsi.Srb = srb;
// prepare the SRB with default values
srb->Length = SCSI_REQUEST_BLOCK_SIZE;
srb->Function = SRB_FUNCTION_EXECUTE_SCSI;
srb->QueueAction = SRB_SIMPLE_TAG_REQUEST;
srb->SrbStatus = 0;
srb->ScsiStatus = 0;
srb->NextSrb = NULL;
srb->SenseInfoBufferLength = SENSE_BUFFER_SIZE;
srb->SenseInfoBuffer = DeviceExtension->ScratchContext.ScratchSense;
srb->DataBuffer = DataBuffer;
srb->DataTransferLength = RequiredLength;
srb->QueueSortKey = logicalBlockAddr.LowPart;
if (logicalBlockAddr.QuadPart > 0xFFFFFFFF)
{
//
// If the requested LBA is more than max ULONG set the
// QueueSortKey to the maximum value, so that these
// requests can be added towards the end of the queue.
//
srb->QueueSortKey = 0xFFFFFFFF;
}
srb->OriginalRequest = irp;
srb->TimeOutValue = DeviceExtension->TimeOutValue;
if (RequestIsRealtimeStreaming(OriginalRequest, IsReadRequest) &&
!TEST_FLAG(DeviceExtension->PrivateFdoData->HackFlags, FDO_HACK_NO_STREAMING))
{
if (IsReadRequest)
{
RtlZeroMemory(&cdb->READ12, sizeof(cdb->READ12));
REVERSE_BYTES(&cdb->READ12.LogicalBlock, &logicalBlockAddr.LowPart);
REVERSE_BYTES(&cdb->READ12.TransferLength, &numTransferBlocks);
cdb->READ12.Streaming = 1;
cdb->READ12.OperationCode = SCSIOP_READ12;
srb->CdbLength = sizeof(cdb->READ12);
}
else
{
RtlZeroMemory(&cdb->WRITE12, sizeof(cdb->WRITE12));
REVERSE_BYTES(&cdb->WRITE12.LogicalBlock, &logicalBlockAddr.LowPart);
REVERSE_BYTES(&cdb->WRITE12.TransferLength, &numTransferBlocks);
cdb->WRITE12.Streaming = 1;
cdb->WRITE12.OperationCode = SCSIOP_WRITE12;
srb->CdbLength = sizeof(cdb->WRITE12);
}
}
else
{
RtlZeroMemory(&cdb->CDB10, sizeof(cdb->CDB10));
cdb->CDB10.LogicalBlockByte0 = ((PFOUR_BYTE)&logicalBlockAddr.LowPart)->Byte3;
cdb->CDB10.LogicalBlockByte1 = ((PFOUR_BYTE)&logicalBlockAddr.LowPart)->Byte2;
cdb->CDB10.LogicalBlockByte2 = ((PFOUR_BYTE)&logicalBlockAddr.LowPart)->Byte1;
cdb->CDB10.LogicalBlockByte3 = ((PFOUR_BYTE)&logicalBlockAddr.LowPart)->Byte0;
cdb->CDB10.TransferBlocksMsb = ((PFOUR_BYTE)&numTransferBlocks)->Byte1;
cdb->CDB10.TransferBlocksLsb = ((PFOUR_BYTE)&numTransferBlocks)->Byte0;
cdb->CDB10.OperationCode = (IsReadRequest) ? SCSIOP_READ : SCSIOP_WRITE;
srb->CdbLength = sizeof(cdb->CDB10);
}
// Set SRB and IRP flags
srb->SrbFlags = DeviceExtension->SrbFlags;
if (TEST_FLAG(originalIrp->Flags, IRP_PAGING_IO) ||
TEST_FLAG(originalIrp->Flags, IRP_SYNCHRONOUS_PAGING_IO))
{
SET_FLAG(srb->SrbFlags, SRB_CLASS_FLAGS_PAGING);
}
SET_FLAG(srb->SrbFlags, (IsReadRequest) ? SRB_FLAGS_DATA_IN : SRB_FLAGS_DATA_OUT);
SET_FLAG(srb->SrbFlags, SRB_FLAGS_ADAPTER_CACHE_ENABLE);
//
// If the request is not split, we can use the original IRP MDL. If the
// request needs to be split, we need to use a partial MDL. The partial MDL
// is needed because more than one driver might be mapping the same MDL
// and this causes problems.
//
if (UsePartialMdl == FALSE)
{
irp->MdlAddress = originalIrp->MdlAddress;
}
else
{
if (DeviceExtension->ScratchContext.PartialMdlIsBuilt != FALSE)
{
MmPrepareMdlForReuse(DeviceExtension->ScratchContext.PartialMdl);
}
IoBuildPartialMdl(originalIrp->MdlAddress, DeviceExtension->ScratchContext.PartialMdl, srb->DataBuffer, srb->DataTransferLength);
DeviceExtension->ScratchContext.PartialMdlIsBuilt = TRUE;
irp->MdlAddress = DeviceExtension->ScratchContext.PartialMdl;
}
//DBGLOGSENDPACKET(Pkt);
//HISTORYLOGSENDPACKET(Pkt);
//
// Set the original irp here for SFIO.
//
srb->SrbExtension = (PVOID)(originalIrp);
return;
}
_IRQL_requires_max_(APC_LEVEL)
NTSTATUS
ScratchBuffer_ExecuteCdbEx(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_opt_ WDFREQUEST OriginalRequest,
_In_ ULONG TransferSize,
_In_ BOOLEAN GetDataFromDevice,
_In_ PCDB Cdb,
_In_ UCHAR OprationLength,
_In_ ULONG TimeoutValue
)
/*++
Routine Description:
Use Scratch buffer to send the Cdb, check error and retry if necessary.
Arguments:
DeviceExtension - device context
OriginalRequest - original request that requires this CDB operation
TransferSize - Data transfer size required
GetFromDevice - TRUE if getting data from device.
Cdb - SCSI command
OprationLength - SCSI command length: 6, 10 or 12
TimeoutValue - if > 0, use it as timeout value for command
if 0, use the default device timeout value
Return Value:
NTSTATUS
--*/
{
NTSTATUS status = STATUS_SUCCESS;
PSCSI_REQUEST_BLOCK srb = DeviceExtension->ScratchContext.ScratchSrb;
PCDB cdb = (PCDB)(srb->Cdb);
BOOLEAN shouldRetry = TRUE;
ULONG timesAlreadyRetried = 0;
LONGLONG retryIn100nsUnits = 0;
PAGED_CODE ();
while (shouldRetry)
{
ScratchBuffer_SetupSrb(DeviceExtension, OriginalRequest, TransferSize, GetDataFromDevice);
// Set up the SRB/CDB
RtlCopyMemory(cdb, Cdb, sizeof(CDB));
srb->CdbLength = OprationLength;
if (TimeoutValue > 0)
{
srb->TimeOutValue = TimeoutValue;
}
ScratchBuffer_SendSrb(DeviceExtension, TRUE, NULL);
if ((DeviceExtension->ScratchContext.ScratchSrb->SrbStatus == SRB_STATUS_ABORTED) &&
(DeviceExtension->ScratchContext.ScratchSrb->InternalStatus == STATUS_CANCELLED))
{
shouldRetry = FALSE;
status = STATUS_CANCELLED;
}
else
{
shouldRetry = RequestSenseInfoInterpretForScratchBuffer(DeviceExtension,
timesAlreadyRetried,
&status,
&retryIn100nsUnits);
if (shouldRetry)
{
LARGE_INTEGER t;
t.QuadPart = -retryIn100nsUnits;
timesAlreadyRetried++;
KeDelayExecutionThread(KernelMode, FALSE, &t);
// keep items clean
ScratchBuffer_ResetItems(DeviceExtension, FALSE);
}
}
}
return status;
}
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