1.3 Overview

This document describes the structure of common file system control (FSCTL) codes, file information levels, and file system information levels that are issued in client/server and server/server communications. These structures do not result in a protocol, but their structure is common across multiple protocols. As such, they are placed in this document as a reference that can be used by other protocols to ensure consistency and accuracy.

File system control codes are parameters to the device I/O control interface between applications and the operating system. These device I/O control functions, like other I/O functions, accept a file handle as a parameter, indicating the resource on which the requested operation is performed. When the operating system detects that a handle corresponds to a file on a remote file server, the request can be redirected over the network to the server where the file is stored.

The following topics are addressed in this specification:

  • Common file system control operations, including the control code itself and the input/output parameters.

  • File information classes and their corresponding structures.

  • File system information classes and their corresponding structures.

  • File attribute definitions and NTSTATUS code definitions referenced by the file system control code, file information level, and file system information-level documentation.