Add build cfg for FUSE mounting implementation to fuser

README.md

@@ -1,3 +1,7 @@
+This is a fork of the excellent [`fuser`](https://github.com/cberner/fuser) Rust crate for FUSE bindings, with some Mountpoint-specific changes to improve performance of concurrent operations. We'll be working to upstream these changes soon.
+
+---
+
 # FUSE (Filesystem in Userspace) for Rust
 
 ![CI](https://github.com/cberner/fuser/actions/workflows/ci.yml/badge.svg)

build.rs

@@ -1,46 +1,51 @@
 fn main() {
+    // Register rustc cfg for switching between mount implementations.
+    // When fuser MSRV is updated to v1.77 or above, we should switch from 'cargo:' to 'cargo::' syntax.
+    println!("cargo:rustc-check-cfg=cfg(fuser_mount_impl, values(\"pure-rust\", \"libfuse2\", \"libfuse3\"))");
+
     #[cfg(all(not(feature = "libfuse"), not(target_os = "linux")))]
     unimplemented!("Building without libfuse is only supported on Linux");
 
+    #[cfg(not(feature = "libfuse"))]
+    {
+        println!("cargo:rustc-cfg=fuser_mount_impl=\"pure-rust\"");
+    }
     #[cfg(feature = "libfuse")]
     {
-        #[cfg(target_os = "macos")]
-        {
+        if cfg!(target_os = "macos") {
             if pkg_config::Config::new()
                 .atleast_version("2.6.0")
                 .probe("fuse") // for macFUSE 4.x
                 .map_err(|e| eprintln!("{}", e))
                 .is_ok()
             {
-                println!("cargo:rustc-cfg=feature=\"libfuse2\"");
+                println!("cargo:rustc-cfg=fuser_mount_impl=\"libfuse2\"");
                 println!("cargo:rustc-cfg=feature=\"macfuse-4-compat\"");
             } else {
                 pkg_config::Config::new()
                     .atleast_version("2.6.0")
                     .probe("osxfuse") // for osxfuse 3.x
                     .map_err(|e| eprintln!("{}", e))
                     .unwrap();
-                println!("cargo:rustc-cfg=feature=\"libfuse2\"");
+                println!("cargo:rustc-cfg=fuser_mount_impl=\"libfuse2\"");
             }
-        }
-        #[cfg(not(target_os = "macos"))]
-        {
+        } else {
             // First try to link with libfuse3
             if pkg_config::Config::new()
                 .atleast_version("3.0.0")
                 .probe("fuse3")
                 .map_err(|e| eprintln!("{e}"))
                 .is_ok()
             {
-                println!("cargo:rustc-cfg=feature=\"libfuse3\"");
+                println!("cargo:rustc-cfg=fuser_mount_impl=\"libfuse3\"");
             } else {
                 // Fallback to libfuse
                 pkg_config::Config::new()
                     .atleast_version("2.6.0")
                     .probe("fuse")
                     .map_err(|e| eprintln!("{e}"))
                     .unwrap();
-                println!("cargo:rustc-cfg=feature=\"libfuse2\"");
+                println!("cargo:rustc-cfg=fuser_mount_impl=\"libfuse2\"");
             }
         }
     }

examples/hello.rs

@@ -50,15 +50,15 @@
 struct HelloFS;
 
 impl Filesystem for HelloFS {
-    fn lookup(&mut self, _req: &Request, parent: u64, name: &OsStr, reply: ReplyEntry) {
+    fn lookup(&self, _req: &Request, parent: u64, name: &OsStr, reply: ReplyEntry) {
         if parent == 1 && name.to_str() == Some("hello.txt") {
             reply.entry(&TTL, &HELLO_TXT_ATTR, 0);
         } else {
             reply.error(ENOENT);
         }
     }
 
-    fn getattr(&mut self, _req: &Request, ino: u64, _fh: Option<u64>, reply: ReplyAttr) {
+    fn getattr(&self, _req: &Request, ino: u64, _fh: Option<u64>, reply: ReplyAttr) {
         match ino {
             1 => reply.attr(&TTL, &HELLO_DIR_ATTR),
             2 => reply.attr(&TTL, &HELLO_TXT_ATTR),
@@ -67,7 +67,7 @@
     }
 
     fn read(
-        &mut self,
+        &self,
         _req: &Request,
         ino: u64,
         _fh: u64,
@@ -81,11 +81,11 @@
             reply.data(&HELLO_TXT_CONTENT.as_bytes()[offset as usize..]);
         } else {
             reply.error(ENOENT);
         }
     }
 
     fn readdir(
-        &mut self,
+        &self,
         _req: &Request,
         ino: u64,
         _fh: u64,

examples/ioctl.rs

@@ -10,12 +10,13 @@
 use libc::{EINVAL, ENOENT};
 use log::debug;
 use std::ffi::OsStr;
+use std::sync::Mutex;
 use std::time::{Duration, UNIX_EPOCH};
 
 const TTL: Duration = Duration::from_secs(1); // 1 second
 
 struct FiocFS {
-    content: Vec<u8>,
+    content: Mutex<Vec<u8>>,
     root_attr: FileAttr,
     fioc_file_attr: FileAttr,
 }
@@ -62,23 +63,23 @@
         };
 
         Self {
-            content: vec![],
+            content: vec![].into(),
             root_attr,
             fioc_file_attr,
         }
     }
 }
 
 impl Filesystem for FiocFS {
-    fn lookup(&mut self, _req: &Request, parent: u64, name: &OsStr, reply: ReplyEntry) {
+    fn lookup(&self, _req: &Request, parent: u64, name: &OsStr, reply: ReplyEntry) {
         if parent == 1 && name.to_str() == Some("fioc") {
             reply.entry(&TTL, &self.fioc_file_attr, 0);
         } else {
             reply.error(ENOENT);
         }
     }
 
-    fn getattr(&mut self, _req: &Request, ino: u64, _fh: Option<u64>, reply: ReplyAttr) {
+    fn getattr(&self, _req: &Request, ino: u64, _fh: Option<u64>, reply: ReplyAttr) {
         match ino {
             1 => reply.attr(&TTL, &self.root_attr),
             2 => reply.attr(&TTL, &self.fioc_file_attr),
@@ -87,7 +88,7 @@
     }
 
     fn read(
-        &mut self,
+        &self,
         _req: &Request,
         ino: u64,
         _fh: u64,
@@ -98,14 +99,15 @@
         reply: ReplyData,
     ) {
         if ino == 2 {
-            reply.data(&self.content[offset as usize..])
+            let content = self.content.lock().unwrap();
+            reply.data(&content[offset as usize..])
         } else {
             reply.error(ENOENT);
         }
     }
 
     fn readdir(
-        &mut self,
+        &self,
         _req: &Request,
         ino: u64,
         _fh: u64,
@@ -133,7 +135,7 @@
     }
 
     fn ioctl(
-        &mut self,
+        &self,
         _req: &Request<'_>,
         ino: u64,
         _fh: u64,
@@ -153,12 +155,12 @@
 
         match cmd.into() {
             FIOC_GET_SIZE => {
-                let size_bytes = self.content.len().to_ne_bytes();
+                let size_bytes = self.content.lock().unwrap().len().to_ne_bytes();
                 reply.ioctl(0, &size_bytes);
             }
             FIOC_SET_SIZE => {
                 let new_size = usize::from_ne_bytes(in_data.try_into().unwrap());
-                self.content = vec![0_u8; new_size];
+                *self.content.lock().unwrap() = vec![0_u8; new_size];
                 reply.ioctl(0, &[]);
             }
             _ => {

examples/notify_inval_entry.rs

@@ -68,7 +68,7 @@
 }
 
 impl<'a> Filesystem for ClockFS<'a> {
-    fn lookup(&mut self, _req: &Request, parent: u64, name: &OsStr, reply: ReplyEntry) {
+    fn lookup(&self, _req: &Request, parent: u64, name: &OsStr, reply: ReplyEntry) {
         if parent != FUSE_ROOT_ID || name != AsRef::<OsStr>::as_ref(&self.get_filename()) {
             reply.error(ENOENT);
             return;
@@ -78,7 +78,7 @@
         reply.entry(&self.timeout, &ClockFS::stat(ClockFS::FILE_INO).unwrap(), 0);
     }
 
-    fn forget(&mut self, _req: &Request, ino: u64, nlookup: u64) {
+    fn forget(&self, _req: &Request, ino: u64, nlookup: u64) {
         if ino == ClockFS::FILE_INO {
             let prev = self.lookup_cnt.fetch_sub(nlookup, SeqCst);
             assert!(prev >= nlookup);
@@ -87,15 +87,15 @@
         }
     }
 
-    fn getattr(&mut self, _req: &Request, ino: u64, _fh: Option<u64>, reply: ReplyAttr) {
+    fn getattr(&self, _req: &Request, ino: u64, _fh: Option<u64>, reply: ReplyAttr) {
         match ClockFS::stat(ino) {
             Some(a) => reply.attr(&self.timeout, &a),
             None => reply.error(ENOENT),
         }
     }
 
     fn readdir(
-        &mut self,
+        &self,
         _req: &Request,
         ino: u64,
         _fh: u64,

examples/notify_inval_inode.rs

@@ -67,7 +67,7 @@
 }
 
 impl<'a> Filesystem for ClockFS<'a> {
-    fn lookup(&mut self, _req: &Request, parent: u64, name: &OsStr, reply: ReplyEntry) {
+    fn lookup(&self, _req: &Request, parent: u64, name: &OsStr, reply: ReplyEntry) {
         if parent != FUSE_ROOT_ID || name != AsRef::<OsStr>::as_ref(&Self::FILE_NAME) {
             reply.error(ENOENT);
             return;
@@ -77,7 +77,7 @@
         reply.entry(&Duration::MAX, &self.stat(ClockFS::FILE_INO).unwrap(), 0);
     }
 
-    fn forget(&mut self, _req: &Request, ino: u64, nlookup: u64) {
+    fn forget(&self, _req: &Request, ino: u64, nlookup: u64) {
         if ino == ClockFS::FILE_INO {
             let prev = self.lookup_cnt.fetch_sub(nlookup, SeqCst);
             assert!(prev >= nlookup);
@@ -86,15 +86,15 @@
         }
     }
 
-    fn getattr(&mut self, _req: &Request, ino: u64, _fh: Option<u64>, reply: ReplyAttr) {
+    fn getattr(&self, _req: &Request, ino: u64, _fh: Option<u64>, reply: ReplyAttr) {
         match self.stat(ino) {
             Some(a) => reply.attr(&Duration::MAX, &a),
             None => reply.error(ENOENT),
         }
     }
 
     fn readdir(
-        &mut self,
+        &self,
         _req: &Request,
         ino: u64,
         _fh: u64,
@@ -120,7 +120,7 @@
         }
     }
 
-    fn open(&mut self, _req: &Request, ino: u64, flags: i32, reply: ReplyOpen) {
+    fn open(&self, _req: &Request, ino: u64, flags: i32, reply: ReplyOpen) {
         if ino == FUSE_ROOT_ID {
             reply.error(EISDIR);
         } else if flags & libc::O_ACCMODE != libc::O_RDONLY {
@@ -134,7 +134,7 @@
     }
 
     fn read(
-        &mut self,
+        &self,
         _req: &Request,
         ino: u64,
         _fh: u64,

examples/poll.rs

@@ -81,7 +81,7 @@ impl FSelFS {
 }
 
 impl fuser::Filesystem for FSelFS {
-    fn lookup(&mut self, _req: &Request, parent: u64, name: &OsStr, reply: fuser::ReplyEntry) {
+    fn lookup(&self, _req: &Request, parent: u64, name: &OsStr, reply: fuser::ReplyEntry) {
         if parent != FUSE_ROOT_ID || name.len() != 1 {
             reply.error(ENOENT);
             return;
@@ -101,7 +101,7 @@ impl fuser::Filesystem for FSelFS {
         reply.entry(&Duration::ZERO, &self.get_data().filestat(idx), 0);
     }
 
-    fn getattr(&mut self, _req: &Request, ino: u64, _fh: Option<u64>, reply: fuser::ReplyAttr) {
+    fn getattr(&self, _req: &Request, ino: u64, _fh: Option<u64>, reply: fuser::ReplyAttr) {
         if ino == FUSE_ROOT_ID {
             let a = FileAttr {
                 ino: FUSE_ROOT_ID,
@@ -132,7 +132,7 @@ impl fuser::Filesystem for FSelFS {
     }
 
     fn readdir(
-        &mut self,
+        &self,
         _req: &Request,
         ino: u64,
         _fh: u64,
@@ -169,7 +169,7 @@ impl fuser::Filesystem for FSelFS {
         reply.ok();
     }
 
-    fn open(&mut self, _req: &Request, ino: u64, flags: i32, reply: fuser::ReplyOpen) {
+    fn open(&self, _req: &Request, ino: u64, flags: i32, reply: fuser::ReplyOpen) {
         let idx = FSelData::ino_to_idx(ino);
         if idx >= NUMFILES {
             reply.error(ENOENT);
@@ -196,7 +196,7 @@ impl fuser::Filesystem for FSelFS {
     }
 
     fn release(
-        &mut self,
+        &self,
         _req: &Request,
         _ino: u64,
         fh: u64,
@@ -215,7 +215,7 @@ impl fuser::Filesystem for FSelFS {
     }
 
     fn read(
-        &mut self,
+        &self,
         _req: &Request,
         _ino: u64,
         fh: u64,
@@ -247,7 +247,7 @@ impl fuser::Filesystem for FSelFS {
     }
 
     fn poll(
-        &mut self,
+        &self,
         _req: &Request,
         _ino: u64,
         fh: u64,