FSCTL_OFFLOAD_WRITE_OUTPUT structure

The FSCTL_OFFLOAD_WRITE_OUTPUT structure contains the output for the FSCTL_OFFLOAD_WRITE control code request.

Syntax

typedef struct _FSCTL_OFFLOAD_WRITE_OUTPUT {
  ULONG     Size;
  ULONG     Flags;
  ULONGLONG LengthWritten;
} FSCTL_OFFLOAD_WRITE_OUTPUT, *PFSCTL_OFFLOAD_WRITE_OUTPUT;

Members

Size

The size of this structure. Set this member to sizeof(FSCTL_OFFLOAD_WRITE_OUTPUT).

Flags

Result flags for the offload write operation. This value is either 0 or the following:

Value Meaning
OFFLOAD_READ_FLAG_FILE_TOO_SMALL
0x00000001
The file to write to is too small for an offload operation.

LengthWritten

The length of data written for the transfer specified in FSCTL_OFFLOAD_WRITE_INPUT.

Remarks

The resulting length written, LengthWritten, may be smaller than what was originally specified in the CopyLength member of FSCTL_OFFLOAD_WRITE_INPUT. A smaller value indicates that less data was able to be logically written with the specified Token than was requested.

If less data than requested was written, the write operation may be completed by performing another FSCTL_OFFLOAD_WRITE request. The next request uses an updated FileOffset member in the FSCTL_OFFLOAD_WRITE_INPUT structure with the value in LengthWritten and an adjusted write length of the previous length minus the value in LengthWritten. Also, an incomplete write operation can be completed through a non-offloaded write method, using the ZwWriteFile routine, for example.

Requirements

   
Minimum supported client Available starting with Windows 8.
Header ntifs.h (include Ntifs.h, Fltkernel.h)

See Also

FSCTL_OFFLOAD_WRITE

FSCTL_OFFLOAD_WRITE_INPUT