File-System Interface


  1. Abraham Silberschatz, Greg Gagne, and Peter Baer Galvin, "Operating System Concepts, Ninth Edition ", Chapter 11

11.1 File Concept

11.1.1 File Attributes

11.1.2 File Operations

Figure 11.2 - File-locking example in Java.

11.1.3 File Types

Figure 11.3 - Common file types.

11.1.4 File Structure

11.1.5 Internal File Structure

11.2 Access Methods

11.2.1 Sequential Access

Figure 11.4 - Sequential-access file.

11.2.2 Direct Access

Figure 11.5 - Simulation of sequential access on a direct-access file.

11.2.3 Other Access Methods

Figure 11.6 - Example of index and relative files.

11.3 Directory Structure

11.3.1 Storage Structure

Figure 11.7 - A typical file-system organization.

11.3.2 Directory Overview

11.3.3. Single-Level Directory

Figure 11.9 - Single-level directory.

11.3.4 Two-Level Directory

Figure 11.10 - Two-level directory structure.

11.3.5 Tree-Structured Directories

Figure 11.11 - Tree-structured directory structure.

11.3.6 Acyclic-Graph Directories

Figure 11.12 - Acyclic-graph directory structure.

11.3.7 General Graph Directory

Figure 11.13 - General graph directory.

11.4 File-System Mounting

Figure 11.14 - File system. (a) Existing system. (b) Unmounted volume.

Figure 11.15 - Mount point.

11.5 File Sharing

11.5.1 Multiple Users

11.5.2 Remote File Systems The Client-Server Model Distributed Information Systems Failure Modes

11.5.3 Consistency Semantics UNIX Semantics Session Semantics Immutable-Shared-Files Semantics

11.6 Protection

11.6.1 Types of Access

11.6.2 Access Control


Files Directories
R Read ( view ) file contents. Read directory contents. Required to get a listing of the directory.
W Write ( change ) file contents. Change directory contents. Required to create or delete files.
X Execute file contents as a program. Access detailed directory information. Required to get a long listing, or to access any specific file in the directory. Note that if a user has X but not R permissions on a directory, they can still access specific files, but only if they already know the name of the file they are trying to access.


Figure 11.16 - Windows 7 access-control list management.


11.6.3 Other Protection Approaches and Issues

11.7 Summary