From ce86ecc1b4b74683a4f477bff8e76f57bcf2b964 Mon Sep 17 00:00:00 2001
From: Colin Walters <walters@verbum.org>
Date: Sat, 19 Oct 2024 12:55:11 +0000
Subject: [PATCH] Use tempfile by default

Per discussion this crate is widely used and there's
no reason to carry even a small reimplementation.
---
 Cargo.toml    |  2 +-
 src/lib.rs    |  1 -
 src/mount.rs  | 15 ++++++---------
 src/tmpdir.rs | 35 -----------------------------------
 4 files changed, 7 insertions(+), 46 deletions(-)
 delete mode 100644 src/tmpdir.rs

diff --git a/Cargo.toml b/Cargo.toml
index 79bc9d5..e501093 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,10 +12,10 @@ rand = "0.8.5"
 rustix = { version = "0.38.37", features = ["fs", "mount", "process"] }
 sha2 = "0.10.8"
 tar = "0.4.42"
+tempfile = "3.13.0"
 zstd = "0.13.2"
 
 [dev-dependencies]
-tempfile = "3.13.0"
 
 [profile.dev.package.sha2]
 # this is *really* slow otherwise
diff --git a/src/lib.rs b/src/lib.rs
index 46209d3..cdfe8cd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -6,4 +6,3 @@ pub mod mount;
 pub mod oci;
 pub mod repository;
 pub mod splitstream;
-pub mod tmpdir;
diff --git a/src/mount.rs b/src/mount.rs
index 45d5993..aa422b3 100644
--- a/src/mount.rs
+++ b/src/mount.rs
@@ -23,10 +23,7 @@ use rustix::mount::{
     unmount,
 };
 
-use crate::{
-    fsverity,
-    tmpdir,
-};
+use crate::fsverity;
 
 struct FsHandle {
     pub fd: OwnedFd,
@@ -58,21 +55,21 @@ impl Drop for FsHandle {
 }
 
 struct TmpMount {
-    pub dir: tmpdir::TempDir,
+    pub dir: tempfile::TempDir,
 }
 
 impl TmpMount {
     pub fn mount(fs: BorrowedFd) -> Result<TmpMount> {
-        let tmp = tmpdir::TempDir::new()?;
+        let tmp = tempfile::TempDir::new()?;
         let mnt = fsmount(fs, FsMountFlags::FSMOUNT_CLOEXEC, MountAttrFlags::empty())?;
-        move_mount(mnt.as_fd(), "", rustix::fs::CWD, &tmp.path, MoveMountFlags::MOVE_MOUNT_F_EMPTY_PATH)?;
+        move_mount(mnt.as_fd(), "", rustix::fs::CWD, tmp.path(), MoveMountFlags::MOVE_MOUNT_F_EMPTY_PATH)?;
         Ok(TmpMount { dir: tmp })
     }
 }
 
 impl Drop for TmpMount {
     fn drop(&mut self) {
-        unmount(&self.dir.path, UnmountFlags::DETACH)
+        unmount(self.dir.path(), UnmountFlags::DETACH)
             .expect("umount(MNT_DETACH) failed");
     }
 }
@@ -92,7 +89,7 @@ pub fn mount_fd<F: AsFd>(image: F, basedir: &Path, mountpoint: &str) -> Result<(
 
         // unfortunately we can't do this via the fd: we need a tmpdir mountpoint
         let tmp = TmpMount::mount(erofs.as_fd())?;  // NB: must live until the "create" operation
-        fsconfig_set_string(overlayfs.as_fd(), "lowerdir+", &tmp.dir.path)?;
+        fsconfig_set_string(overlayfs.as_fd(), "lowerdir+", tmp.dir.path())?;
         fsconfig_set_string(overlayfs.as_fd(), "datadir+", basedir)?;
         fsconfig_create(overlayfs.as_fd())?;
 
diff --git a/src/tmpdir.rs b/src/tmpdir.rs
deleted file mode 100644
index ff384d1..0000000
--- a/src/tmpdir.rs
+++ /dev/null
@@ -1,35 +0,0 @@
-use std::path::PathBuf;
-
-use anyhow::{
-    Result,
-    bail,
-};
-use rand::distributions::{Alphanumeric, DistString};
-
-pub struct TempDir {
-    pub path: PathBuf,
-}
-
-impl TempDir {
-    pub fn new() -> Result<TempDir>{
-        let tmp = PathBuf::from("/tmp");
-
-        for _ in 0 .. 26*26*26 {  // this is how many times glibc tries
-            let suffix = Alphanumeric.sample_string(&mut rand::thread_rng(), 6);
-            let path = tmp.join(format!("composefs.{}", suffix));
-            match std::fs::create_dir(&path) {
-                Ok(()) => return Ok(TempDir { path }),
-                Err(e) if e.kind() == std::io::ErrorKind::AlreadyExists => continue,
-                Err(e) => Err(e)?
-            }
-        }
-
-        bail!("Failed to find free name for temporary directory");
-    }
-}
-
-impl Drop for TempDir {
-    fn drop(&mut self) {
-        std::fs::remove_dir(&self.path).expect("can't remove tempdir");
-    }
-}