swapped RENAME_EXCHANGE with nix renameat

Author: hz2

src/uu/mv/Cargo.toml

@@ -40,6 +40,7 @@ windows-sys = { workspace = true, features = [
 
 [target.'cfg(unix)'.dependencies]
 libc = { workspace = true }
+nix = { workspace = true, features = ["fs"] }
 
 [[bin]]
 name = "mv"

src/uu/mv/src/mv.rs

@@ -356,54 +356,39 @@ fn determine_overwrite_mode(matches: &ArgMatches) -> OverwriteMode {
 /// Atomically exchange two files using renameat2 with `RENAME_EXCHANGE`
 #[cfg(target_os = "linux")]
 fn exchange_files(path1: &Path, path2: &Path, opts: &Options) -> UResult<()> {
-    use std::ffi::CString;
-    use std::os::unix::ffi::OsStrExt;
-
-    // Convert paths to C strings
-    let c_path1 = CString::new(path1.as_os_str().as_bytes()).unwrap();
-    let c_path2 = CString::new(path2.as_os_str().as_bytes()).unwrap();
-
-    // RENAME_EXCHANGE flag for renameat2
-    const RENAME_EXCHANGE: libc::c_int = 2;
+    use nix::fcntl::{AT_FDCWD, RenameFlags, renameat2};
 
     // Use renameat2 to atomically exchange the files
-    let result = unsafe {
-        libc::syscall(
-            libc::SYS_renameat2,
-            libc::AT_FDCWD,
-            c_path1.as_ptr(),
-            libc::AT_FDCWD,
-            c_path2.as_ptr(),
-            RENAME_EXCHANGE,
-        )
-    };
-
-    if result == 0 {
-        if opts.verbose {
-            println!("exchanged '{}' <-> '{}'", path1.display(), path2.display());
-        }
-        Ok(())
-    } else {
-        let errno = unsafe { *libc::__errno_location() };
-        match errno {
-            libc::ENOTSUP | libc::EINVAL => Err(USimpleError::new(
-                1,
-                translate!("--exchange is not supported on this filesystem"),
-            )),
-            libc::ENOENT => {
-                let missing_path = if path1.exists() { path2 } else { path1 };
-                Err(MvError::NoSuchFile(missing_path.display().to_string()).into())
+    match renameat2(
+        AT_FDCWD,
+        path1,
+        AT_FDCWD,
+        path2,
+        RenameFlags::RENAME_EXCHANGE,
+    ) {
+        Ok(()) => {
+            if opts.verbose {
+                println!("exchanged '{}' <-> '{}'", path1.display(), path2.display());
             }
-            libc::EXDEV => Err(USimpleError::new(
-                1,
-                translate!("--exchange cannot exchange files across different filesystems"),
-            )),
-            _ => {
-                let error_msg = io::Error::from_raw_os_error(errno);
-                Err(USimpleError::new(
+            Ok(())
+        }
+        Err(err) => {
+            use nix::errno::Errno;
+
+            match err {
+                nix::Error::ENOTSUP | nix::Error::EINVAL => Err(USimpleError::new(
+                    1,
+                    translate!("--exchange is not supported on this filesystem"),
+                )),
+                nix::Error::ENOENT => {
+                    let missing_path = if path1.exists() { path2 } else { path1 };
+                    Err(MvError::NoSuchFile(missing_path.display().to_string()).into())
+                }
+                nix::Error::EXDEV => Err(USimpleError::new(
                     1,
-                    format!("exchange failed: {error_msg}"),
-                ))
+                    translate!("--exchange cannot exchange files across different filesystems"),
+                )),
+                _ => Err(USimpleError::new(1, format!("exchange failed: {err}"))),
             }
         }
     }