perf(linux/rm): optimize descriptor usage by keeping dir_fd open in safe_remove_dir_recursive_impl

Reuse the existing directory file descriptor instead of opening/closing new ones for each subdirectory or file during recursive removal. This simplifies the code, reduces overhead from descriptor management, and prevents potential deep descriptor stacks on systems with many nested directories. Removed unnecessary `drop(dir_fd)` call and adjusted progress bar increments accordingly.

Author: mattsu2020

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

@@ -343,7 +343,7 @@ pub fn safe_remove_dir_recursive_impl(
         }
     };
 
-    // Collect names and stat data, then drop FD to avoid deep descriptor stacks
+    // Collect names and stat data
     let mut collected = Vec::with_capacity(entries.len());
     for entry_name in entries {
         match dir_fd.stat_at(&entry_name, false) {
@@ -356,7 +356,6 @@ pub fn safe_remove_dir_recursive_impl(
             }
         }
     }
-    drop(dir_fd); // free descriptor before descending
 
     let mut error = false;
 
@@ -383,32 +382,18 @@ pub fn safe_remove_dir_recursive_impl(
             }
 
             if !child_error {
-                match DirFd::open(path) {
-                    Ok(fd) => {
-                        if let Some(pb) = progress_bar {
-                            pb.inc(1);
-                        }
-                        error = handle_unlink(&fd, entry_name.as_ref(), &entry_path, true, options)
-                            || error;
-                    }
-                    Err(e) => {
-                        error = handle_error_with_force(e, &entry_path, options) || error;
-                    }
+                if let Some(pb) = progress_bar {
+                    pb.inc(1);
                 }
+                error = handle_unlink(&dir_fd, entry_name.as_ref(), &entry_path, true, options)
+                    || error;
             }
         } else if prompt_file_with_stat(&entry_path, &entry_stat, options) {
-            match DirFd::open(path) {
-                Ok(fd) => {
-                    if let Some(pb) = progress_bar {
-                        pb.inc(1);
-                    }
-                    error = handle_unlink(&fd, entry_name.as_ref(), &entry_path, false, options)
-                        || error;
-                }
-                Err(e) => {
-                    error = handle_error_with_force(e, &entry_path, options) || error;
-                }
+            if let Some(pb) = progress_bar {
+                pb.inc(1);
             }
+            error = handle_unlink(&dir_fd, entry_name.as_ref(), &entry_path, false, options)
+                || error;
         }
     }