SCSI_WMI_REQUEST_BLOCK structure (srb.h)
This structure is a special version of a SCSI_REQUEST_BLOCK for use with WMI commands.
Syntax
typedef struct _SCSI_WMI_REQUEST_BLOCK {
USHORT Length;
UCHAR Function;
UCHAR SrbStatus;
UCHAR WMISubFunction;
UCHAR PathId;
UCHAR TargetId;
UCHAR Lun;
UCHAR Reserved1;
UCHAR WMIFlags;
UCHAR Reserved2[2];
ULONG SrbFlags;
ULONG DataTransferLength;
ULONG TimeOutValue;
PVOID DataBuffer;
PVOID DataPath;
PVOID Reserved3;
PVOID OriginalRequest;
PVOID SrbExtension;
ULONG Reserved4;
ULONG Reserved6;
UCHAR Reserved5[16];
} SCSI_WMI_REQUEST_BLOCK, *PSCSI_WMI_REQUEST_BLOCK;
Members
Length
Specifies the size in bytes of this structure.
Function
SRB_FUNCTION_WMI, which specifies that the request is a WMI request. If this member is not set to SRB_FUNCTION_WMI, the miniport driver should fail the request.
SrbStatus
Returns the status of the completed request. This member should be set by the miniport driver before it notifies the OS-specific driver that the request has completed by calling ScsiPortNotification with RequestComplete. The value of this member can be any value listed for SrbStatus in SCSI_REQUEST_BLOCK.
WMISubFunction
Indicates the WMI action to be performed. A miniport driver calls ScsiPortWmiDispatchFunction with MinorFunction set to this value. The subfunction value corresponds to the WMI minor IRP number that identifies the WMI operation.
PathId
Indicates the SCSI port or bus for the request. This value is zero-based. If SRB_WMI_FLAGS_ADAPTER_REQUEST is set in WMIFlags, this member is reserved.
TargetId
Indicates the target controller or device on the bus. If SRB_WMI_FLAGS_ADAPTER_REQUEST is set in WMIFlags, this member is reserved.
Lun
Indicates the logical unit number of the device. If SRB_WMI_FLAGS_ADAPTER_REQUEST is set in WMIFlags, this member is reserved.
Reserved1
Reserved for system use and not available for use by miniport drivers.
WMIFlags
Indicates that the WMI request is for the adapter if SRB_WMI_FLAGS_ADAPTER_REQUEST is set and that PathId, TargetId, and Lun are reserved. Otherwise, WMIFlags will be NULL, indicating that the request is for the device specified by PathId, TargetId, and Lun.
Reserved2[2]
Reserved for system use and not available for use by miniport drivers.
SrbFlags
Indicates various parameters and options about the request. SrbFlags is read-only. This member will be set to one or more of the following flags ORed together:
SRB_FLAGS_DATA_IN
Indicates data will be transferred from the device to the system.
SRB_FLAGS_DATA_OUT
Indicates data will be transferred from the system to the device.
SRB_FLAGS_NO_DATA_TRANSFER
Indicates no data transfer with this request. If this is set, the flags SRB_FLAGS_DATA_OUT, SRB_FLAGS_DATA_IN, and SRB_FLAGS_UNSPECIFIED_DIRECTION are clear.
SRB_FLAGS_DISABLE_SYNCH_TRANSFER
Indicates the HBA, if possible, should perform asynchronous I/O for this transfer request. If synchronous I/O was negotiated previously, the HBA must renegotiate for asynchronous I/O before performing the transfer.
SRB_FLAGS_DISABLE_DISCONNECT
Indicates the HBA should not allow the target to disconnect from the SCSI bus during processing of this request.
DataTransferLength
Indicates the size in bytes of the data buffer. A miniport driver calls ScsiPortWmiDispatchFunction with BufferSize set to this value. If an underrun occurs, the miniport driver must update this member to the number of bytes actually transferred.
TimeOutValue
Indicates the interval in seconds that the request can execute before the OS-specific port driver might consider it timed out. Miniport drivers are not required to time requests because the port driver already does.
DataBuffer
Points to the data buffer. A miniport driver calls ScsiPortWmiDispatchFunction with Buffer set to this value. Miniport drivers can use this value as a data pointer regardless of the value of MapBuffers in the PORT_CONFIGURATION_INFORMATION for the HBA. A miniport driver cannot transfer data directly into the buffer using DMA.
DataPath
Specifies the WMI data path for this request. A miniport driver calls ScsiPortWmiDispatchFunction with DataPath set to this value.
Reserved3
Reserved for system use and not available for use by miniport drivers.
OriginalRequest
Points to the IRP for this request. This member is irrelevant to miniport drivers.
SrbExtension
Points to the Srb extension. A miniport driver must not use this member if it set SrbExtensionSize to zero in the HW_INITIALIZATION_DATA. The memory at SrbExtension is not initialized by the OS-specific port driver, and the miniport driver-determined data can be accessed directly by the HBA. The corresponding physical address can be obtained by calling ScsiPortGetPhysicalAddress with the SrbExtension pointer.
Reserved4
Reserved for system use and not available for use by miniport drivers.
Reserved6
Reserved for system use and not available for use by miniport drivers. This member is valid starting with Windows Server 2003 with SP1.
Reserved5[16]
Reserved for system use and not available for use by miniport drivers.
Remarks
Windows NT storage class and filter drivers can send WMI SRBs to the system port driver. The system port driver will handle certain WMI requests on behalf of miniport drivers. If the port driver cannot handle a WMI request, it forwards the request to the miniport driver.
A miniport driver receives WMI requests from the port driver only if the miniport driver set WmiDataProvider in the PORT_CONFIGURATION_INFORMATION structure. If the miniport driver supports a request, it should process it and complete the request by calling ScsiPortNotification twice, first with RequestComplete and then with NextRequest (or NextLuRequest).
For information about supporting WMI in miniport drivers, see the Windows Management Instrumentation.
Requirements
| Requirement | Value |
|---|---|
| Header | srb.h (include Storport.h, Srb.h, Storport.h, Minitape.h) |