applied: [PATCH proxmox-fuse-rs v1] Add statfs support to proxmox-fuse

[Wolfgang Bumiller <w.bumiller@proxmox.com>]

applied

I added a small follow-up commit, see the comment below inline.

I also added `#[non_exhaustive]` to `Request` so we can add entries
without major version bumps.

Bumped to v3 so it can be used right away.

On Thu, Feb 12, 2026 at 03:05:47PM +0800, Kefu Chai wrote:
> - Add fuse_reply_statfs FFI binding in sys.rs
> - Add Statfs request struct in requests.rs
> - Add Statfs variant to Request enum
> - Add statfs callback to FuseData
> - Add enable_statfs() method to FuseSessionBuilder
> 
> This enables filesystems to handle statfs requests and return filesystem statistics.
> 
> Signed-off-by: Kefu Chai <k.chai@proxmox.com>
> ---
>  examples/tmpfs/main.rs |  4 ++--
>  src/requests.rs        | 24 ++++++++++++++++++++++++
>  src/session.rs         | 17 +++++++++++++++++
>  src/sys.rs             |  1 +
>  4 files changed, 44 insertions(+), 2 deletions(-)
> 
> diff --git a/examples/tmpfs/main.rs b/examples/tmpfs/main.rs
> index f3f7d26..36db9e8 100644
> --- a/examples/tmpfs/main.rs
> +++ b/examples/tmpfs/main.rs
> @@ -3,11 +3,11 @@ use std::ffi::OsStr;
>  use std::path::Path;
>  use std::{io, mem};
>  
> -use anyhow::{bail, format_err, Error};
> +use anyhow::{Error, bail, format_err};
>  use futures::future::FutureExt;
>  use futures::select;
>  use futures::stream::TryStreamExt;
> -use tokio::signal::unix::{signal, SignalKind};
> +use tokio::signal::unix::{SignalKind, signal};
>  
>  use proxmox_fuse::requests::{self, FuseRequest, SetTime};
>  use proxmox_fuse::{EntryParam, Fuse, ReplyBufState, Request};
> diff --git a/src/requests.rs b/src/requests.rs
> index d1846cc..458b956 100644
> --- a/src/requests.rs
> +++ b/src/requests.rs
> @@ -106,6 +106,7 @@ pub enum Request {
>      Forget(Forget),
>      Getattr(Getattr),
>      Setattr(Setattr),
> +    Statfs(Statfs),
>      Readdir(Readdir),
>      ReaddirPlus(ReaddirPlus),
>      Mkdir(Mkdir),
> @@ -144,6 +145,7 @@ impl FuseRequest for Request {
>              Request::Lookup(r) => r.fail(errno),
>              Request::Getattr(r) => r.fail(errno),
>              Request::Setattr(r) => r.fail(errno),
> +            Request::Statfs(r) => r.fail(errno),
>              Request::Readdir(r) => r.fail(errno),
>              Request::ReaddirPlus(r) => r.fail(errno),
>              Request::Mkdir(r) => r.fail(errno),
> @@ -239,6 +241,28 @@ impl Getattr {
>      }
>  }
>  
> +/// Get filesystem statistics.
> +///
> +/// This is the equivalent of a `statfs` call.
> +#[derive(Debug)]
> +pub struct Statfs {
> +    pub(crate) request: RequestGuard,
> +    pub inode: u64,
> +}
> +
> +impl FuseRequest for Statfs {
> +    fn fail(self, errno: libc::c_int) -> io::Result<()> {
> +        reply_err(self.request, errno)
> +    }
> +}
> +
> +impl Statfs {
> +    /// Send a reply for a `Statfs` request.
> +    pub fn reply(self, stbuf: &libc::statvfs) -> io::Result<()> {
> +        reply_result!(self: sys::fuse_reply_statfs(self.request.raw, stbuf as *const _))

The cast here is actually not necessary. Initially I just replaced it
with `&raw const *stbuf` (since `&raw {const,mut}` is a thing now in
rust) - only after pushing out the change did I realize that the cast is
actually completely unnecessary, since references are automatically
converted to pointers in this case anyway...

> +    }
> +}
> +
>  /// Get the contents of a directory without changing any lookup counts. (Contrary to
>  /// `ReaddirPlus`).
>  #[derive(Debug)]
> diff --git a/src/session.rs b/src/session.rs
> index 62a8a9e..3e4841c 100644
> --- a/src/session.rs
> +++ b/src/session.rs
> @@ -94,6 +94,17 @@ impl FuseData {
>              }));
>      }
>  
> +    extern "C" fn statfs(request: sys::Request, inode: u64) {
> +        let fuse_data = unsafe { &*(sys::fuse_req_userdata(request) as *mut FuseData) };
> +        fuse_data
> +            .pending_requests
> +            .borrow_mut()
> +            .push_back(Request::Statfs(requests::Statfs {
> +                request: RequestGuard::from_raw(request),
> +                inode,
> +            }));
> +    }
> +
>      extern "C" fn readdir(
>          request: sys::Request,
>          inode: u64,
> @@ -547,6 +558,12 @@ impl FuseSessionBuilder {
>          self
>      }
>  
> +    /// Enable `Statfs` requests.
> +    pub fn enable_statfs(mut self) -> Self {
> +        self.operations.statfs = Some(FuseData::statfs);
> +        self
> +    }
> +
>      /// Enable `Unlink` requests.
>      pub fn enable_unlink(mut self) -> Self {
>          self.operations.unlink = Some(FuseData::unlink);
> diff --git a/src/sys.rs b/src/sys.rs
> index 17a01de..186b0ec 100644
> --- a/src/sys.rs
> +++ b/src/sys.rs
> @@ -77,6 +77,7 @@ unsafe extern "C" {
>      pub fn fuse_reply_readlink(req: Request, link: StrPtr) -> c_int;
>      pub fn fuse_reply_none(req: Request);
>      pub fn fuse_reply_write(req: Request, count: libc::size_t) -> c_int;
> +    pub fn fuse_reply_statfs(req: Request, stbuf: *const libc::statvfs) -> c_int;
>      pub fn fuse_req_userdata(req: Request) -> MutPtr;
>      pub fn fuse_add_direntry_plus(req: Request, buf: MutStrPtr, bufsize: size_t, name: StrPtr, stbuf: Option<&EntryParam>, off: c_int) -> size_t;
>      pub fn fuse_add_direntry(req: Request, buf: MutStrPtr, bufsize: size_t, name: StrPtr, stbuf: Option<&libc::stat>, off: c_int) -> size_t;
> -- 
> 2.47.3
> 
> 
> 
> 
>