xfs support in test_rename_directory_to_non_empty_directory

[Hoverbear]

While running Ferrocene's test suite we use a variety of filesystems, including XFS. Those systems caught a failing test in a recent upstream pull.

The test failing:

rust/library/std/src/fs/tests.rs

Lines 2141 to 2157 in 1ea1171

	#[test]
	#[cfg_attr(target_vendor = "win7", ignore = "Unsupported under Windows 7.")]
	fn test_rename_directory_to_non_empty_directory() {
	// Renaming a directory over a non-empty existing directory should fail.
	let tmpdir: TempDir = tmpdir();
	let source_path = tmpdir.join("source_directory");
	let target_path = tmpdir.join("target_directory");
	fs::create_dir(&source_path).unwrap();
	fs::create_dir(&target_path).unwrap();
	fs::write(target_path.join("target_file.txt"), b"target hello world").unwrap();
	let err = fs::rename(source_path, target_path).unwrap_err();
	assert_eq!(err.kind(), ErrorKind::DirectoryNotEmpty);
	}

It was recently removed from being Windows-only in: a0298aa#diff-0ec4075fea7f5f4cc82c306e975ae7638b1fc500d30c11a83f337a69ef1dfd65L2177

Seemingly on XFS only, the AlreadyExists variant is returned instead.

This workaround allows both possible errors. I am unsure at this time if it is a signal of incorrectness in Rust somewhere, but on Python a similar failure can be noted:

ana@autonoma ~/git/ferrocene/scratch
❯ mkdir blap flap
ana@autonoma ~/git/ferrocene/scratch
❯ touch flap/zap
ana@autonoma ~/git/ferrocene/scratch
❯ python
Python 3.13.13 (main, May 15 2026, 12:38:54) [GCC 15.2.1 20260214] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.rename("blap", "flap")
Traceback (most recent call last):
  File "<python-input-3>", line 1, in <module>
    os.rename("blap", "flap")
    ~~~~~~~~~^^^^^^^^^^^^^^^^
FileExistsError: [Errno 17] File exists: 'blap' -> 'flap'
ana@autonoma ~/git/ferrocene/scratch
❯ cd /tmp/
ana@autonoma /tmp
❯ mkdir blap flap
ana@autonoma /tmp
❯ touch flap/zap
ana@autonoma /tmp
❯ python
Python 3.13.13 (main, May 15 2026, 12:38:54) [GCC 15.2.1 20260214] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.rename("blap", "flap")
Traceback (most recent call last):
  File "<python-input-1>", line 1, in <module>
    os.rename("blap", "flap")
    ~~~~~~~~~^^^^^^^^^^^^^^^^
OSError: [Errno 39] Directory not empty: 'blap' -> 'flap'

I tested on ext4, tmpfs, overlayfs, btrfs, and xfs. Only XFS seems to display this error.

Reproduction

On Linux hosts:

use clap::Parser;

struct Args {
    /// Destination to try
    #[arg()]
    path: std::path::PathBuf,
}

fn main() {
    let args = Args::parse();

    // Renaming a directory over a non-empty existing directory should fail.
    let tmpdir = std::path::Path::new(&args.path);
    std::fs::create_dir_all(tmpdir).unwrap();

    let source_path = tmpdir.join("source_directory");
    let target_path = tmpdir.join("target_directory");

    std::fs::create_dir(&source_path).unwrap();
    std::fs::create_dir(&target_path).unwrap();

    let target_path_file = target_path.join("target_file.txt");
    std::fs::write(target_path.join("target_file.txt"), b"target hello world").unwrap();
    println!("wrote {target_path_file:?}");

    println!("{source_path:?} -> {target_path:?}");
    let err = std::fs::rename(source_path, target_path).unwrap_err();
    assert_eq!(err.kind(), std::io::ErrorKind::DirectoryNotEmpty);
}

XFS_BLOCK=image-xfs
truncate -s 512M image-xfs
mkfs.xfs -q image-xfs
mkdir mnt-xfs
sudo mount -o loop image-xfs mnt-xfs
sudo chmod 777 mnt-xfs
cargo run -- mnt-xfs/

Output:

wrote "mnt-xfs/target_directory/target_file.txt"
"mnt-xfs/source_directory" -> "mnt-xfs/target_directory"

thread 'main' (267220) panicked at src/main.rs:30:5:
assertion `left == right` failed
  left: AlreadyExists
 right: DirectoryNotEmpty
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

You can run this test directly:

./x.py --stage 2 test library/std --target x86_64-unknown-linux-gnu -- fs::tests::test_rename_directory_to_non_empty_directory --nocapture

[rustbot]

r? @Mark-Simulacrum

rustbot has assigned @Mark-Simulacrum.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

Why was this reviewer chosen?

The reviewer was selected based on:

• Owners of files modified in this PR: @ChrisDenton, libs
• @ChrisDenton, libs expanded to 8 candidates

[the8472]

This workaround allows both possible errors. I am unsure at this time if it is a signal of incorrectness in Rust somewhere

The linux rename(2) manpage says

 ENOTEMPTY or EEXIST
        newpath is a nonempty directory, that is, contains entries other than "." and "..".

So this looks correct.