Upgrade nix

Two major changes:
 - features must be included; we only need two (this will speed up
   compiles!)
 - FD safety; we now need an OwnedFd, so attempting to use the fd after
   the object is dropped is no longer valid. Additionally, we don't need
   to implement Drop, as OwnedFd already has a drop which calls close

References:

 * nix-rust/nix#2091 - nix PR for features drop
 * https://doc.rust-lang.org/stable/src/std/os/fd/owned.rs.html#170-182 - OwnedFd docs
 * nix-rust/nix#1906 - nix PR for FD I/O safety

firewood/Cargo.toml

@@ -27,7 +27,7 @@ futures = "0.3.24"
 hex = "0.4.3"
 lru = "0.11.0"
 metered = "0.9.0"
-nix = "0.26.1"
+nix = {version = "0.27.1", features = ["fs", "uio"]}
 parking_lot = "0.12.1"
 primitive-types = { version = "0.12.0", features = ["impl-rlp"] }
 rlp = "0.5.2"

firewood/src/db.rs

@@ -33,7 +33,7 @@ use std::{
     num::NonZeroUsize,
     path::Path,
     sync::Arc,
-    thread::JoinHandle,
+    thread::JoinHandle, os::fd::AsFd,
 };
 
 const MERKLE_META_SPACE: SpaceId = 0x0;
@@ -407,7 +407,7 @@ impl Db {
         let root_hash_path = file::touch_dir("root_hash", &db_path)?;
 
         let file0 = crate::file::File::new(0, SPACE_RESERVED, &merkle_meta_path)?;
-        let fd0 = file0.get_fd();
+        let fd0 = file0.as_fd();
 
         if reset {
             // initialize dbparams

firewood/src/file.rs

@@ -3,15 +3,14 @@
 
 // Copied from CedrusDB
 
-use std::os::fd::IntoRawFd;
-pub(crate) use std::os::unix::io::RawFd as Fd;
+use std::ops::Deref;
+use std::os::fd::OwnedFd;
+
 use std::path::{Path, PathBuf};
 use std::{io::ErrorKind, os::unix::prelude::OpenOptionsExt};
 
-use nix::unistd::close;
-
 pub struct File {
-    fd: Fd,
+    fd: OwnedFd,
 }
 
 #[derive(PartialEq, Eq)]
@@ -25,28 +24,26 @@ impl File {
         rootpath: PathBuf,
         fname: &str,
         options: Options,
-    ) -> Result<Fd, std::io::Error> {
+    ) -> Result<OwnedFd, std::io::Error> {
         let mut filepath = rootpath;
         filepath.push(fname);
         Ok(std::fs::File::options()
             .truncate(options == Options::Truncate)
             .read(true)
             .write(true)
             .mode(0o600)
-            .open(filepath)?
-            .into_raw_fd())
+            .open(filepath)?.into())
     }
 
-    pub fn create_file(rootpath: PathBuf, fname: &str) -> Result<Fd, std::io::Error> {
+    pub fn create_file(rootpath: PathBuf, fname: &str) -> Result<OwnedFd, std::io::Error> {
         let mut filepath = rootpath;
         filepath.push(fname);
         Ok(std::fs::File::options()
             .create(true)
             .read(true)
             .write(true)
             .mode(0o600)
-            .open(filepath)?
-            .into_raw_fd())
+            .open(filepath)?.into())
     }
 
     fn _get_fname(fid: u64) -> String {
@@ -65,16 +62,14 @@ impl File {
         };
         Ok(File { fd })
     }
-
-    pub fn get_fd(&self) -> Fd {
-        self.fd
-    }
 }
 
-impl Drop for File {
-    fn drop(&mut self) {
-        close(self.fd).unwrap();
+impl Deref for File {
+    fn deref(&self) -> &Self::Target {
+        &self.fd
     }
+
+    type Target = OwnedFd;
 }
 
 pub fn touch_dir(dirname: &str, rootdir: &Path) -> Result<PathBuf, std::io::Error> {

firewood/src/storage/buffer.rs

@@ -1,6 +1,7 @@
 //! Disk buffer for staging in memory pages and flushing them to disk.
 use std::fmt::Debug;
 use std::ops::IndexMut;
+use std::os::fd::{AsRawFd, AsFd};
 use std::path::{Path, PathBuf};
 use std::rc::Rc;
 use std::sync::Arc;
@@ -227,7 +228,7 @@ fn schedule_write(
             .unwrap()
             .get_file(fid)
             .unwrap();
-        aiomgr.write(file.get_fd(), offset & fmask, p.staging_data.clone(), None)
+        aiomgr.write(file.as_raw_fd(), offset & fmask, p.staging_data.clone(), None)
     };
 
     let task = {
@@ -304,7 +305,7 @@ async fn init_wal(
                                         e, final_path
                                     ))
                                 })?
-                                .get_fd(),
+                                .as_fd(),
                             &redo.data,
                             (offset & file_mask) as nix::libc::off_t,
                         )

firewood/src/storage/mod.rs

@@ -10,7 +10,7 @@ use std::{
     num::NonZeroUsize,
     ops::{Deref, DerefMut},
     path::PathBuf,
-    sync::Arc,
+    sync::Arc, os::fd::{AsFd, AsRawFd},
 };
 use thiserror::Error;
 use tokio::sync::{mpsc::error::SendError, oneshot::error::RecvError};
@@ -779,7 +779,7 @@ impl CachedSpaceInner {
                         let mut page: Page = Page::new([0; PAGE_SIZE as usize]);
 
                         nix::sys::uio::pread(
-                            file.get_fd(),
+                            file.as_fd(),
                             page.deref_mut(),
                             (poff & (file_size - 1)) as nix::libc::off_t,
                         )
@@ -901,7 +901,7 @@ impl FilePool {
             rootdir: rootdir.to_path_buf(),
         };
         let f0 = s.get_file(0)?;
-        if flock(f0.get_fd(), FlockArg::LockExclusiveNonblock).is_err() {
+        if flock(f0.as_raw_fd(), FlockArg::LockExclusiveNonblock).is_err() {
             return Err(StoreError::Init("the store is busy".into()));
         }
         Ok(s)
@@ -931,7 +931,7 @@ impl FilePool {
 impl Drop for FilePool {
     fn drop(&mut self) {
         let f0 = self.get_file(0).unwrap();
-        flock(f0.get_fd(), FlockArg::UnlockNonblock).ok();
+        flock(f0.as_raw_fd(), FlockArg::UnlockNonblock).ok();
     }
 }
 

growth-ring/Cargo.toml

@@ -15,7 +15,7 @@ scan_fmt = "0.2.6"
 regex = "1.6.0"
 async-trait = "0.1.57"
 futures = "0.3.24"
-nix = "0.26.2"
+nix = {version = "0.27.1", features = ["fs", "uio"]}
 libc = "0.2.133"
 bytemuck = {version = "1.13.1", features = ["derive"]}
 thiserror = "1.0.40"