fuser-ng

fuser-ng is a higher-level, path-oriented FUSE filesystem library for Rust, built on top of fuser 0.17.

It started as a fork of fuse-mt. The 0.7 series moved the crate to fuser 0.17, uses fuser's native threading instead of an internal thread pool, and adds a new inode table that keeps descendant paths correct when a parent directory is renamed. Version 0.8 refines the public path API for inode-aware getattr and create callbacks.

Overview

fuser exposes low-level FUSE kernel operations. fuser-ng wraps those operations with an API that is closer to the FUSE C API and simpler to implement for path-based filesystems.

The crate:

• translates FUSE inodes into paths;
• lets Filesystem methods return std::io::Result values instead of using fuser reply objects directly;
• provides default ENOSYS implementations for operations you do not support;
• simplifies readdir by handling FUSE pagination internally;
• uses fuser's threaded event loop, configurable with ThreadCount;
• adds broader unit and integration test coverage than the original fuse-mt codebase, including inode-table rename cases and passthrough FUSE operations.

Path API

Filesystem methods receive path-oriented types instead of raw inode numbers:

• EntryName is a child name resolved relative to a parent directory. It is used for operations such as mkdir, mknod, symlink, unlink, and rename.
• ResolvedPath is an entry path with its inode attached. It is used when FuserNG already has an inode for the entry, including operations such as open, read, write, and create.
• EntryRef is used by getattr, which may run either while resolving a parent/name lookup or after an inode has already been resolved.

The inode table stores complete paths for directories and derives leaf paths from their parent directories. This keeps descendants consistent after a directory subtree is renamed.

Usage

Add the crate to your Cargo.toml:

[dependencies]
fuser-ng = "0.8"

Implement fuser_ng::Filesystem, then wrap it before mounting:

let options = [fuser_ng::MountOption::FSName("myfs".into())];

fuser_ng::mount(
    fuser_ng::FuserNG::new(filesystem),
    mountpoint,
    &options,
    fuser_ng::ThreadCount::Default,
)?;