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标题: UsbStorage驱动开发（二）[原创] [打印本页]

作者: maingao 时间: 2005-8-22 11:11 标题: UsbStorage驱动开发（二）[原创]

UsbStore_ReadWrite这一函数不做任何实际有用的读写操作。 NTSTATUS UsbStore_ReadWrite( IN PDEVICE_OBJECT DeviceObject, IN PIRP Irp ) { #if DBG DbgPrint("Enter ReadWrite Dispatch!\n"); #endif Irp->IoStatus.Status = STATUS_INVALID_PARAMETER; Irp->IoStatus.Information = 0; IoCompleteRequest(Irp,IO_NO_INCREMENT); return STATUS_INVALID_PARAMETER; } UsbStore_Scsi将上层DRIVER的IRP_MJ_SCSI的请求排队， NTSTATUS UsbStore_Scsi(IN PDEVICE_OBJECT UsbStorePdo, IN PIRP Irp) { PUSBSTORE_DEVICE_EXTENSION pUsbStoreDeviceExtension = UsbStorePdo->DeviceExtension; PIO_STACK_LOCATION irpStackLocation = IoGetCurrentIrpStackLocation(Irp); PSCSI_REQUEST_BLOCK Srb = irpStackLocation->Parameters.Scsi.Srb; NTSTATUS status; KIRQL Irql; if(pUsbStoreDeviceExtension->DeviceType == USBSTORE_PDO) { if(Srb->Function == SRB_FUNCTION_EXECUTE_SCSI) { if(Srb->DataTransferLength <=0x10000) { Srb->SrbStatus = SRB_STATUS_PENDING; IoMarkIrpPending(Irp); IoStartPacket(UsbStorePdo, Irp, &Srb->QueueSortKey, (PDRIVER_CANCEL)UsbStore_CancelRoutine); status = STATUS_PENDING; } else { status = STATUS_INVALID_PARAMETER; } } else if(Srb->Function == SRB_FUNCTION_CLAIM_DEVICE) { KeAcquireSpinLock(&pUsbStoreDeviceExtension->SpinLock, &Irql); if(pUsbStoreDeviceExtension->DeviceFlags&0x01) { status = STATUS_END_OF_FILE; Srb->SrbStatus = SRB_STATUS_BUSY; } else { pUsbStoreDeviceExtension->DeviceFlags|=0x01; Srb->DataBuffer = UsbStorePdo; Srb->SrbStatus = SRB_STATUS_SUCCESS; } KeReleaseSpinLock(&pUsbStoreDeviceExtension->SpinLock, Irql); } else if(Srb->Function == SRB_FUNCTION_RELEASE_DEVICE) { KeAcquireSpinLock(&pUsbStoreDeviceExtension->SpinLock,&Irql); pUsbStoreDeviceExtension->DeviceFlags &= 0xFFFFFFFE; KeReleaseSpinLock(&pUsbStoreDeviceExtension->SpinLock, Irql); Srb->SrbStatus = SRB_STATUS_SUCCESS; status = STATUS_SUCCESS; } else if(Srb->Function == SRB_FUNCTION_FLUSH) { Srb->SrbStatus = SRB_STATUS_SUCCESS; status = STATUS_SUCCESS; } else { status = STATUS_NOT_SUPPORTED; } } else { status = STATUS_NOT_SUPPORTED; } if(status != STATUS_PENDING) { Irp->IoStatus.Status = STATUS_SUCCESS; IoCompleteRequest(Irp, IO_NO_INCREMENT); } return status; } 而UsbStore_StartIo函数将排队的IRP通过CBI规范或者BULK ONLY规范发送给设备， VOID UsbStore_StartIo( IN PDEVICE_OBJECT UsbStorePdo, IN PIRP Irp ) { ULONG TempFlags; PSCSI_REQUEST_BLOCK Srb; UCHAR DeviceErrorFlags ; ULONG NeedSenseRequestFlags; PUSBSTORE_DEVICE_EXTENSION pUsbStoreDeviceExtension = UsbStorePdo->DeviceExtension; PIO_STACK_LOCATION irpStackLocation; KIRQL Irql; irpStackLocation = IoGetCurrentIrpStackLocation(Irp); if(irpStackLocation->MajorFunction == IRP_MJ_POWER) { Irp->IoStatus.Status = STATUS_SUCCESS; PoStartNextPowerIrp(Irp); IoCompleteRequest(Irp,IO_NO_INCREMENT); return; } else { IoAcquireCancelSpinLock(&Irql); InterlockedExchange((PULONG)&Irp->CancelRoutine,0); if(Irp->Cancel != 0) { KeAcquireSpinLockAtDpcLevel(&pUsbStoreDeviceExtension->SpinLock); pUsbStoreDeviceExtension->DeviceFlags = pUsbStoreDeviceExtension->DeviceFlags>>3; pUsbStoreDeviceExtension->DeviceFlags = ~pUsbStoreDeviceExtension->DeviceFlags; pUsbStoreDeviceExtension->DeviceFlags = pUsbStoreDeviceExtension->DeviceFlags&1; TempFlags = pUsbStoreDeviceExtension->DeviceFlags; KeReleaseSpinLockFromDpcLevel(&pUsbStoreDeviceExtension->SpinLock); IoReleaseCancelSpinLock(Irql); Irp->IoStatus.Status = STATUS_CANCELLED; Irp->IoStatus.Information = 0; IoCompleteRequest(Irp,IO_NO_INCREMENT); if(TempFlags==0) return; else IoStartNextPacket(UsbStorePdo, TRUE); return; } else { IoReleaseCancelSpinLock(Irql); DeviceErrorFlags = 0; NeedSenseRequestFlags = 0; Srb = irpStackLocation->Parameters.Scsi.Srb; pUsbStoreDeviceExtension->Srb = Srb; KeAcquireSpinLockAtDpcLevel(&pUsbStoreDeviceExtension->SpinLock); if(pUsbStoreDeviceExtension->DeviceFlags&DEVICE_ERROR) { DeviceErrorFlags = 1; } else { pUsbStoreDeviceExtension->SrbTimeOutValue = Srb->TimeOutValue; if(pUsbStoreDeviceExtension->DeviceFlags&NEED_SENSEREQUEST) { NeedSenseRequestFlags = 1; pUsbStoreDeviceExtension->DeviceFlags&=~NEED_SENSEREQUEST; } } KeReleaseSpinLockFromDpcLevel(&pUsbStoreDeviceExtension->SpinLock); if(DeviceErrorFlags ==0) { UsbStore_FormatSrb(UsbStorePdo,Irp,Srb,1); if(pUsbStoreDeviceExtension->DriverFlags==1) { UsbStore_BulkOnly(UsbStorePdo,Irp); return; } else { if(NeedSenseRequestFlags == 0||Srb->Cdb[0] == SCSIOP_REQUEST_SENSE) { UsbStore_CBI(UsbStorePdo, Irp); return; } else { UsbStore_CBIGetRequestSense(UsbStorePdo,Irp,1); return; } } } else { Irp->IoStatus.Status = STATUS_DEVICE_DOES_NOT_EXIST; IoCompleteRequest(Irp, IO_NO_INCREMENT); IoStartNextPacket(UsbStorePdo, TRUE); return; } } } } UsbStore_DeviceIoControl函数负责处理IRP_MJ_DEVICE_CONTROL，其中IOCONTROLCODE主要有IOCTL_SCSI_PASS_THROUGH，IOCTL_SCSI_PASS_THROUGH_DIRECT，IOCTL_STORAGE_QUERY_PROPERTY。限于篇幅，就不将此函数的代码列下。 UsbStore_Pnp函数负责处理IRP_MJ_PNP，USB STORAGE DRIVER的FDO IRP_MJ_PNP的IRP_MN_START_DEVICE负责建立USB连接，建立USB STORAGE DRIVER的PDO。USB STORAGE DRIVER FDO 的IRP_MN_REMOVE_DEVICE负责清除设备资源及USB连接。 USB STORAGE DRIVER PDO的IRP_MN_QUERY_DEVICE_TEXT 和IRP_MN_QUERY_ID是BUS DRIVER的PNP所必须处理的。 (未完待续)

作者: liu1234 时间: 2005-8-23 20:35

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