Advanced File System Simulation in Go

This project is an advanced simulation of a virtual file system written in Go. It demonstrates key concepts in operating system design, including memory-mapped storage, free space management, inodes, and hierarchical directories.

Features

• Memory-Mapped Persistence: Uses mmap-go to map a 10MB virtual disk (virtual_disk.bin) into memory, ensuring real-time persistence of changes.
• Free Space Bitmap: Precisely tracks which 4KB blocks are used and which are free to allow for block reuse.
• Inodes: Implements an inode table with Unix-style permissions (rwxrwxrwx) and Indexed Allocation pointers.
• Directories: Simulates hierarchical directories using DirEntry mappings.
• Interactive Shell: A custom CLI to interact with the virtual disk.

Installation

Ensure you have Go installed, then clone the repository and build the shell:

go mod tidy
go build -o fs-shell ./cmd/shell

Usage

Run the interactive shell:

./fs-shell

Available Commands

• info: Display information about the virtual disk.
• ls: List contents of the current directory.
• mkdir <dirname>: Create a new directory.
• rm [-r] <name>: Remove a file or directory. Use -r to forcefully remove a directory.
• exit: Unmount the disk and close the shell.

Legacy Examples

The older, simplified simulations are still available for reference:

• example1/: Contiguous file system simulation.
• example2/: Paged file system simulation.
• chunks/: Chunk calculation test.

License

This project is licensed under the terms of the MIT License.