IOCTL_DISK_READ (Compact 2013)
3/26/2014
This I/O control message services FAT file system requests to read data from the block device. Send this message with DeviceIoControl.
Syntax
BOOL DeviceIoControl(
HANDLE hDevice, // handle to device
DWORD dwIoControlCode, // use IOCTL_DISK_READ
LPVOID lpInBuffer, // pointer to input buffer
DWORD nInBufferSize, // input buffer size
LPVOID lpOutBuffer, // pointer to output buffer
DWORD nOutBufferSize, // output buffer size
LPDWORD lpBytesReturned, // number of bytes returned
OVERLAPPED lpOverlapped // pointer to OVERLAPPED structure
);
Parameters
- hDevice
[in] Handle to the device.
- dwIoControlCode
[in] Control code for the operation. Use IOCTL_DISK_READ for this operation.
- lpInBuffer
[in] Pointer to a SG_REQ structure.
- nInBufferSize
[in] Specifies the size of the SG_REQ structure in lpInBuffer.
- lpOutBuffer
Not used.
- nOutBufferSize
Not used.
- lpBytesReturned
[out] Pointer to a DWORD to receive total number of bytes returned. If not needed, set to NULL.
- lpOverlapped
Not used.
Return Values
When this function returns, the FAT file system expects the sr_status member of SG_REQ to receive ERROR_SUCCESS if the read succeeded; otherwise, it receives a standard error return value. Certain errors retry automatically. For example, ERROR_BAD_UNIT retries automatically if you remove the device, and ERROR_NOT_READY retries automatically if the driver is shutting down or starting up. Block device drivers should return ERROR_GEN_FAILURE for any unknown or unexpected errors.
Remarks
This IOCTL call into the block driver is relative to the object store; the object store is the medium that the block driver exposes. This also implies that this IOCTL call is relative to the master boot record (MBR), but block drivers should not make assumptions on the existence of an MBR.
Requirements
Header |
diskio.h |