add signal handling utilities to Mount

Author: ubnt-intrepid

Cargo.toml

@@ -23,7 +23,8 @@ either = "1"
 libc = "0.2"
 num_cpus = "1.17"
 polyfuse-kernel = { version = "0.3.0-dev", path = "crates/polyfuse-kernel" }
-rustix = { version = "1", features = [ "fs", "mount", "net", "param", "pipe", "process", "thread", "use-libc" ] }
+rustix = { version = "1", features = [ "fs", "mount", "net", "param", "pipe", "process", "io_uring", "thread", "use-libc" ] }
+signal-hook = "0.3.18"
 thiserror = "2"
 tracing = "0.1"
 zerocopy = "0.8.26"
@@ -34,7 +35,6 @@ bytes = "1.10.1"
 chrono = "0.4.41"
 dashmap = "6.1"
 pico-args = "0.5"
-signal-hook = "0.3.18"
 slab = ">=0.4.11"
 tempfile = "3.23.0"
 tokio = { version = ">=1.8.4", features = [ "macros", "fs", "io-util", "net", "rt-multi-thread", "sync", "time" ] }

examples/basic.rs

@@ -10,12 +10,10 @@ use polyfuse::{
 };
 
 use anyhow::{ensure, Context as _, Result};
-use libc::{SIGHUP, SIGINT, SIGTERM};
 use rustix::{
     io::Errno,
     process::{getgid, getuid},
 };
-use signal_hook::iterator::Signals;
 use std::{io, path::PathBuf, thread, time::Duration};
 
 const CONTENT: &[u8] = b"Hello from FUSE!\n";
@@ -33,12 +31,8 @@ fn main() -> Result<()> {
         polyfuse::connect(mountpoint, MountOptions::new(), KernelConfig::new())?;
 
     thread::scope(|scope| -> Result<()> {
-        let mut signals = Signals::new([SIGTERM, SIGHUP, SIGINT])?;
-        scope.spawn(move || {
-            if let Some(_sig) = signals.forever().next() {
-                let _ = mount.unmount();
-            }
-        });
+        let mount_handle = mount.handle();
+        scope.spawn(move || mount.unmount_after_interrupted());
 
         // Receive an incoming FUSE request from the kernel.
         let mut buf = session.new_fallback_buffer();
@@ -54,6 +48,8 @@ fn main() -> Result<()> {
             };
         }
 
+        mount_handle.close();
+
         Ok(())
     })?;
 

examples/heartbeat.rs

@@ -21,9 +21,7 @@ use polyfuse::{
 use anyhow::{anyhow, ensure, Context as _, Result};
 use chrono::Local;
 use dashmap::DashMap;
-use libc::{SIGHUP, SIGINT, SIGTERM};
 use rustix::{io::Errno, param::page_size};
-use signal_hook::iterator::Signals;
 use std::{
     io::{self, prelude::*},
     path::PathBuf,
@@ -54,12 +52,8 @@ fn main() -> Result<()> {
     let session = &session;
     let fs = &fs;
     thread::scope(|scope| -> Result<()> {
-        let mut signals = Signals::new([SIGTERM, SIGHUP, SIGINT])?;
-        scope.spawn(move || {
-            if let Some(_sig) = signals.forever().next() {
-                let _ = mount.unmount();
-            }
-        });
+        let mount_handle = mount.handle();
+        scope.spawn(move || mount.unmount_after_interrupted());
 
         // Spawn a task that beats the heart.
         scope.spawn(move || -> Result<()> {
@@ -131,6 +125,8 @@ fn main() -> Result<()> {
             }
         }
 
+        mount_handle.close();
+
         Ok(())
     })?;
 

examples/heartbeat_entry.rs

@@ -20,9 +20,7 @@ use polyfuse::{
 
 use anyhow::{ensure, Context as _, Result};
 use chrono::Local;
-use libc::{SIGHUP, SIGINT, SIGTERM};
 use rustix::io::Errno;
-use signal_hook::iterator::Signals;
 use std::{io, mem, os::unix::prelude::*, path::PathBuf, sync::Mutex, thread, time::Duration};
 
 const FILE_INO: NodeID = match NodeID::from_raw(2) {
@@ -62,12 +60,8 @@ fn main() -> Result<()> {
     let conn = &conn;
     let fs = &fs;
     thread::scope(|scope| -> Result<()> {
-        let mut signals = Signals::new([SIGTERM, SIGHUP, SIGINT])?;
-        scope.spawn(move || {
-            if let Some(_sig) = signals.forever().next() {
-                let _ = mount.unmount();
-            }
-        });
+        let mount_handle = mount.handle();
+        scope.spawn(move || mount.unmount_after_interrupted());
 
         // spawn heartbeat thread.
         scope.spawn(move || fs.heartbeat(session, conn));
@@ -149,6 +143,8 @@ fn main() -> Result<()> {
             }
         }
 
+        mount_handle.close();
+
         Ok(())
     })?;
 

examples/hello.rs

@@ -11,13 +11,11 @@ use polyfuse::{
 };
 
 use anyhow::{ensure, Context as _, Result};
-use libc::{SIGHUP, SIGINT, SIGTERM};
 use rustix::{
     fs::{Gid, Uid},
     io::Errno,
     process::{getgid, getuid},
 };
-use signal_hook::iterator::Signals;
 use std::{os::unix::prelude::*, path::PathBuf, thread, time::Duration};
 
 const TTL: Duration = Duration::from_secs(60 * 60 * 24 * 365);
@@ -42,12 +40,8 @@ fn main() -> Result<()> {
     let fs = Hello::new();
 
     thread::scope(|scope| -> Result<()> {
-        let mut signals = Signals::new([SIGTERM, SIGHUP, SIGINT])?;
-        scope.spawn(move || {
-            if let Some(_sig) = signals.forever().next() {
-                let _ = mount.unmount();
-            }
-        });
+        let mount_handle = mount.handle();
+        scope.spawn(move || mount.unmount_after_interrupted());
 
         let mut buf = session.new_splice_buffer()?;
         while session.recv_request(&conn, &mut buf)? {
@@ -120,6 +114,8 @@ fn main() -> Result<()> {
             }
         }
 
+        mount_handle.close();
+
         Ok(())
     })?;
 

examples/poll.rs

@@ -12,12 +12,10 @@ use polyfuse::{
 };
 
 use anyhow::{ensure, Context as _, Result};
-use libc::{SIGHUP, SIGINT, SIGTERM};
 use rustix::{
     io::Errno,
     process::{getgid, getuid},
 };
-use signal_hook::iterator::Signals;
 use std::{
     collections::HashMap,
     path::PathBuf,
@@ -54,12 +52,8 @@ fn main() -> Result<()> {
     let session = &session;
     let fs = &fs;
     thread::scope(|scope| -> Result<()> {
-        let mut signals = Signals::new([SIGTERM, SIGHUP, SIGINT])?;
-        scope.spawn(move || {
-            if let Some(_sig) = signals.forever().next() {
-                let _ = mount.unmount();
-            }
-        });
+        let mount_handle = mount.handle();
+        scope.spawn(move || mount.unmount_after_interrupted());
 
         let mut buf = session.new_splice_buffer()?;
         while session.recv_request(conn, &mut buf)? {
@@ -179,6 +173,8 @@ fn main() -> Result<()> {
             }
         }
 
+        mount_handle.close();
+
         Ok(())
     })?;
 

src/mount.rs

@@ -3,7 +3,9 @@ mod unpriv_mount;
 
 use self::{priv_mount::PrivMount, unpriv_mount::UnprivMount};
 use bitflags::{bitflags, bitflags_match};
+use libc::{SIGHUP, SIGINT, SIGTERM};
 use rustix::{io::Errno, mount::MountFlags};
+use signal_hook::iterator::Signals;
 use std::{borrow::Cow, io, mem, os::fd::OwnedFd, path::Path};
 
 // refs:
@@ -148,6 +150,7 @@ pub struct Mount {
     kind: MountKind,
     mountpoint: Cow<'static, Path>,
     mountopts: MountOptions,
+    signals: Signals,
 }
 
 #[derive(Debug)]
@@ -174,8 +177,21 @@ impl Mount {
     }
 
     #[inline]
-    pub fn unmount(mut self) -> io::Result<()> {
-        self.unmount_()
+    pub fn handle(&self) -> signal_hook::iterator::Handle {
+        self.signals.handle()
+    }
+
+    #[inline]
+    pub fn unmount_after_interrupted(mut self) -> io::Result<()> {
+        match self.signals.wait().next() {
+            Some(sig) => tracing::debug!(
+                "caught the interruption signal: {:?}",
+                rustix::io_uring::Signal::from_named_raw(sig)
+            ),
+            None => tracing::debug!("caught the closing event from the handle"),
+        }
+        self.unmount_()?;
+        Ok(())
     }
 
     fn unmount_(&mut self) -> io::Result<()> {
@@ -187,12 +203,6 @@ impl Mount {
     }
 }
 
-impl Drop for Mount {
-    fn drop(&mut self) {
-        let _ = self.unmount_();
-    }
-}
-
 pub(crate) fn mount(
     mountpoint: Cow<'static, Path>,
     mut mountopts: MountOptions,
@@ -225,12 +235,15 @@ pub(crate) fn mount(
         },
     };
 
+    let signals = Signals::new([SIGHUP, SIGTERM, SIGINT])?;
+
     Ok((
         fd,
         Mount {
             kind,
             mountpoint,
             mountopts,
+            signals,
         },
     ))
 }