SCSI_PASS_THROUGH_EX structure

Description

The SCSI_PASS_THROUGH_EX structure is used in conjunction with an IOCTL_SCSI_PASS_THROUGH_EX request to instruct the port driver to send an embedded SCSI command to the target device. SCSI_PASS_THROUGH_EX can contain a bi-directional data transfers and a variable length command data block.

[!NOTE] The SCSI port driver and SCSI miniport driver models may be altered or unavailable in the future. Instead, use the Storport driver and Storport miniport driver models.

Members

Version

The version of this structure. Set to 0.

Length

The size of this structure, in bytes. Set to sizeof(SCSI_PASS_THROUGH_EX).

CdbLength

The size of the SCSI command descriptor block in Cdb, in bytes.

StorAddressLength

The length, in bytes, of the storage device address structure at the offset of StorAddressOffset after this structure.

ScsiStatus

Reports the SCSI status that was returned by the HBA or the target device.

SenseInfoLength

The size in bytes of the request-sense buffer. This member is optional and can be set to 0.

DataDirection

Indicates whether the SCSI command will read or write data. This field must be one of the following values:

Reserved

Reserved. Set to 0.

TimeOutValue

Indicates the interval in seconds that the request can execute before the port driver considers it timed out. Do not set this value to 0. Default values often range from:

• Typical operations: 30 to 60 seconds
• Short operations: 10 to 30 seconds
• Medium operations: 30 to 120 seconds
• Long operations (like format, extended self-test): 300 to 3600 seconds or more

StorAddressOffset

The location of the target storage device address structure, in bytes, from the beginning of this structure.

SenseInfoOffset

Offset from the beginning of this structure to the request-sense buffer. Set to 0 if no request-sense buffer is present.

DataOutTransferLength

Indicates the size in bytes of the output data buffer. Many devices transfer chunks of data of predefined length. The value in DataOutTransferLength must be an integral multiple of this predefined, minimum length that is specified by the device. If an underrun occurs, the miniport driver must update this member to the number of bytes actually transferred. If no output data buffer is present, this member is set to 0.

DataInTransferLength

Indicates the size in bytes of the input data buffer. Many devices transfer chunks of data of predefined length. The value in DataInTransferLength must be an integral multiple of this predefined, minimum length that is specified by the device. If an underrun occurs, the miniport driver must update this member to the number of bytes actually transferred. If no input data buffer is present, this member is set to 0.

DataOutBufferOffset

Contains an offset from the beginning of this structure to the output data buffer. The offset must respect the data alignment requirements of the device.

DataInBufferOffset

Contains an offset from the beginning of this structure to the input data buffer. The offset must respect the data alignment requirements of the device.

Cdb

Specifies the SCSI command descriptor block to be sent to the target device.

Remarks

The SCSI_PASS_THROUGH_EX structure is used with the IOCTL_SCSI_PASS_THROUGH_EX control code, which is a buffered device control request. To bypass buffering in system memory, callers should use IOCTL_SCSI_PASS_THROUGH_DIRECT_EX. When handling an IOCTL_SCSI_PASS_THROUGH_DIRECT_EX request, the system locks down the buffer in user memory and the device accesses this memory directly.

[!NOTE] Drivers executing on a 64-bit version of Windows must use the SCSI_PASS_THROUGH32_EX structure as the request data type when handling an IOCTL_SCSI_PASS_THROUGH_EX request from a 32-bit process.

See also

IOCTL_SCSI_PASS_THROUGH

IOCTL_SCSI_PASS_THROUGH_EX

SCSI_PASS_THROUGH