The fuse-backend-rs crate is an rust library to implement Fuse daemons based on the Linux FUSE device (/dev/fuse) or the virtiofs draft specification.
Linux FUSE is an userspace filesystem framework, and the /dev/fuse device node is the interface for userspace filesystem daemons to communicate with the in-kernel fuse driver.
And the virito-fs specification extends the FUSE framework into the virtualization world, which uses the Virtio protocol to transfer FUSE requests and responses between the Fuse client and server. With virtio-fs, the Fuse client runs within the guest kernel and the Fuse server runs on the host userspace or hardware.
So the fuse-rs crate is a library to communicate with the Linux FUSE clients, which includes: - ABI layer, which defines all data structures shared between linux Fuse framework and Fuse daemons. - API layer, defines the interfaces for Fuse daemons to implement a userspace file system. - Transport layer, which supports both the Linux Fuse device and virtio-fs protocol. - VFS/pseudo_fs, an abstraction layer to support multiple file systems by a single virtio-fs device. - A sample passthrough file system implementation, which passes through files from daemons to clients.
A sample fuse server based on the Linux Fuse device (/dev/fuse):
```rust use fusebackendrs::api::{server::Server, Vfs, VfsOptions}; use fusebackendrs::transport::fusedev::{FuseSession, FuseChannel};
struct FuseServer {
server: Arc
impl FuseServer { fn svcloop(&self) -> Result<()> { // Given error EBADF, it means kernel has shut down this session. let _ebadf = std::io::Error::fromrawoserror(libc::EBADF); loop { if let Some((reader, writer)) = self .ch .getrequest() .maperr(|| std::io::Error::fromrawoserror(libc::EINVAL))? { if let Err(e) = self.server.handlemessage(reader, writer, None, None) { match e { fusebackendrs::Error::EncodeMessage(ebadf) => { break; } _ => { error!("Handling fuse message failed"); continue; } } } } else { info!("fuse server exits"); break; } } Ok(()) } } ```
This project is licensed under - Apache License, Version 2.0 - BSD-3-Clause License