shadowFS

A high-performance, dual-tier user-space filesystem implemented in C using the FUSE (Filesystem in Userspace) framework. ⁠shadowFS⁠ bridges persistent disk storage (⁠shadow_storage⁠) with a high-speed LRU-cached memory/disk tier (⁠shadow_cache⁠) to optimize file access latencies.

Features

Dual-Tier Architecture: Automatically manages file reads and writes across a persistent storage backend and a local cache layer.

LRU Caching Mechanism: Implements Least Recently Used eviction policies to manage cache capacity efficiently.

FUSE 3.x Integration: Standard POSIX compliance for seamless mounting, reading, writing, and directory traversal.

Modular Codebase: Clean separation of filesystem callback hooks and core caching algorithms.

Project Structure

shadowFS/ ├── CMakeLists.txt # Build configuration ├── include/ # Header files (cache.h, fs_operations.h) ├── src/ # Source implementation (main.c, cache.c, fs_operations.c) ├── shadow_storage/ # Persistent backend storage tier └── shadow_cache/ # High-speed LRU cache tier

Building and Installation

Prerequisites

C11 compatible compiler (GCC / Clang)

CMake (version 3.10 or higher)

FUSE 3 development libraries (⁠libfuse3-dev⁠)

Compilation

mkdir -p build && cd build cmake .. make

Usage

Mount the filesystem by specifying the binary and an empty mount point directory:

./shadowfs /home/knightrider27/shadow_mount

To cleanly unmount the filesystem:

fusermount3 -u /home/knightrider27/shadow_mount