Simple File System Project

A simulation of a basic file system implemented in C. This project demonstrates core operating system concepts including inodes, blocks, bitmaps, and file operations.

Overview

This project implements a simple file system (SimpleFS) that runs on top of an emulated disk. It handles:

• Superblock management: Filesystem metadata.
• Inode management: File metadata tracking.
• Free block management: Using a bitmap.
• Basic operations: Create, delete, read, write, and more.

Building the Project

To compile the project, run:

make

This generates the simplefs executable.

Running the Shell

The simplefs program acts as a shell to interact with your file system.

Usage:

./simplefs <diskfile> <nblocks>

• <diskfile>: The name of the file to use as the emulated disk (will be created if it doesn't exist).
• <nblocks>: The number of blocks to allocate for the disk.

Example

./simplefs mydisk 200

Shell Commands

Once inside the simplefs> shell, you can use the following commands:

• format: Format the disk (must do this first).
• mount: Mount the file system (must do this after formatting).
• create: Create a new file (returns inumber).
• delete <inumber>: Delete a file.
• cat <inumber>: Display file contents.
• copyin <filename> <inumber>: Copy a file from the host OS into SimpleFS.
• copyout <inumber> <filename>: Copy a file from SimpleFS to the host OS.
• stat <inumber>: Show file statistics.
• debug: Print file system state (superuser block, inodes).
• quit: Exit the shell.

Example Session

simplefs> format
disk formatted.
simplefs> mount
disk mounted.
simplefs> create
created inode 1
simplefs> copyin test.txt 1
wrote 512 bytes to inode 1
simplefs> debug
... (prints fs state) ...
simplefs> quit