refactor(linux/rm): avoid redundant DirFd opening in safe_remove_dir_recursive

Move DirFd opening out of safe_remove_dir_recursive_impl to safe_remove_dir_recursive
to open the directory file descriptor once per level instead of twice, improving efficiency
and reducing potential for errors in recursive directory removal on Linux.

Author: mattsu2020

src/uu/rm/src/platform/linux.rs

@@ -258,11 +258,10 @@ pub fn safe_remove_dir_recursive(
         }
     };
 
-    // Try to open the directory using DirFd for secure traversal
-    if let Err(e) = DirFd::open(path) {
-        // If we can't open the directory for safe traversal,
-        // handle the error appropriately and try to remove if possible
-        if e.kind() == std::io::ErrorKind::PermissionDenied {
+    // Open directory fd once for this level; traversal impl will close it
+    let dir_fd = match DirFd::open(path) {
+        Ok(fd) => fd,
+        Err(e) if e.kind() == std::io::ErrorKind::PermissionDenied => {
             // Try to remove the directory directly if it's empty
             if fs::remove_dir(path).is_ok() {
                 verbose_removed_directory(path, options);
@@ -272,10 +271,10 @@ pub fn safe_remove_dir_recursive(
             // show permission denied error for GNU compatibility
             return show_permission_denied_error(path);
         }
-        return show_removal_error(e, path);
-    }
+        Err(e) => return show_removal_error(e, path),
+    };
 
-    let error = safe_remove_dir_recursive_impl(path, options, progress_bar);
+    let error = safe_remove_dir_recursive_impl(path, dir_fd, options, progress_bar);
 
     // After processing all children, remove the directory itself
     if error {
@@ -313,23 +312,10 @@ pub fn safe_remove_dir_recursive(
 
 pub fn safe_remove_dir_recursive_impl(
     path: &Path,
+    mut dir_fd: DirFd,
     options: &Options,
     progress_bar: Option<&ProgressBar>,
 ) -> bool {
-    // Read directory entries using safe traversal
-    let dir_fd = match DirFd::open(path) {
-        Ok(fd) => fd,
-        Err(e) if e.kind() == std::io::ErrorKind::PermissionDenied => {
-            if !options.force {
-                show_permission_denied_error(path);
-            }
-            return !options.force;
-        }
-        Err(e) => {
-            return handle_error_with_force(e, path, options);
-        }
-    };
-
     let entries = match dir_fd.read_dir() {
         Ok(entries) => entries,
         Err(e) if e.kind() == std::io::ErrorKind::PermissionDenied => {