mkdir: use uucore::mode::UmaskGuard instead of local implementation

Author: sylvestre

src/uu/mkdir/src/mkdir.rs

@@ -3,7 +3,7 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
-// spell-checker:ignore (ToDO) ugoa cmode RAII
+// spell-checker:ignore (ToDO) ugoa cmode
 
 use clap::builder::ValueParser;
 use clap::parser::ValuesRef;
@@ -245,28 +245,6 @@ fn create_dir(path: &Path, is_parent: bool, config: &Config) -> UResult<()> {
     create_single_dir(path, is_parent, config)
 }
 
-/// RAII guard to restore umask on drop, ensuring cleanup even on panic.
-#[cfg(unix)]
-struct UmaskGuard(uucore::libc::mode_t);
-
-#[cfg(unix)]
-impl UmaskGuard {
-    /// Set umask to the given value and return a guard that restores the original on drop.
-    fn set(new_mask: uucore::libc::mode_t) -> Self {
-        let old_mask = unsafe { uucore::libc::umask(new_mask) };
-        Self(old_mask)
-    }
-}
-
-#[cfg(unix)]
-impl Drop for UmaskGuard {
-    fn drop(&mut self) {
-        unsafe {
-            uucore::libc::umask(self.0);
-        }
-    }
-}
-
 /// Create a directory with the exact mode specified, bypassing umask.
 ///
 /// GNU mkdir temporarily sets umask to 0 before calling mkdir(2), ensuring the
@@ -278,7 +256,7 @@ fn create_dir_with_mode(path: &Path, mode: u32) -> std::io::Result<()> {
 
     // Temporarily set umask to 0 so the directory is created with the exact mode.
     // The guard restores the original umask on drop, even if we panic.
-    let _guard = UmaskGuard::set(0);
+    let _guard = mode::UmaskGuard::set(0);
 
     std::fs::DirBuilder::new().mode(mode).create(path)
 }