linux-kernel - [PATCH 06/10] rust: xarray: simplify `Guard::load`

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Message-Id: <20251203-xarray-entry-send-v1-6-9e5ffd5e3cf0@kernel.org>
Date: Wed, 03 Dec 2025 23:26:36 +0100
From: Andreas Hindborg <a.hindborg@...nel.org>
To: Tamir Duberstein <tamird@...il.com>, Miguel Ojeda <ojeda@...nel.org>, 
 Alex Gaynor <alex.gaynor@...il.com>, Boqun Feng <boqun.feng@...il.com>, 
 Gary Guo <gary@...yguo.net>, 
 Björn Roy Baron <bjorn3_gh@...tonmail.com>, 
 Benno Lossin <lossin@...nel.org>, Alice Ryhl <aliceryhl@...gle.com>, 
 Trevor Gross <tmgross@...ch.edu>, Danilo Krummrich <dakr@...nel.org>
Cc: Daniel Gomez <da.gomez@...nel.org>, rust-for-linux@...r.kernel.org, 
 linux-kernel@...r.kernel.org, Andreas Hindborg <a.hindborg@...nel.org>
Subject: [PATCH 06/10] rust: xarray: simplify `Guard::load`

Simplify the implementation by removing the closure-based API from
`Guard::load` in favor of returning `Option<NonNull<c_void>>` directly.

Signed-off-by: Andreas Hindborg <a.hindborg@...nel.org>
---
 rust/kernel/xarray.rs | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/rust/kernel/xarray.rs b/rust/kernel/xarray.rs
index 0f69a523b72bf..ca97134ba2bd0 100644
--- a/rust/kernel/xarray.rs
+++ b/rust/kernel/xarray.rs
@@ -211,16 +211,12 @@ fn from(value: StoreError<T>) -> Self {
 }
 
 impl<'a, T: ForeignOwnable> Guard<'a, T> {
-    fn load<F, U>(&self, index: usize, f: F) -> Option<U>
-    where
-        F: FnOnce(NonNull<c_void>) -> U,
-    {
+    fn load(&self, index: usize) -> Option<NonNull<c_void>> {
         let mut state = XArrayState::new(self, index);
         // SAFETY: `state.state` is always valid by the type invariant of
         // `XArrayState`.
         let ptr = unsafe { bindings::xas_load(&raw mut state.state) };
-        let ptr = NonNull::new(ptr.cast())?;
-        Some(f(ptr))
+        NonNull::new(ptr)
     }
 
     /// Checks if the XArray contains an element at the specified index.
@@ -246,18 +242,17 @@ pub fn contains_index(&self, index: usize) -> bool {
 
     /// Provides a reference to the element at the given index.
     pub fn get(&self, index: usize) -> Option<T::Borrowed<'_>> {
-        self.load(index, |ptr| {
-            // SAFETY: `ptr` came from `T::into_foreign`.
-            unsafe { T::borrow(ptr.as_ptr()) }
-        })
+        let ptr = self.load(index)?;
+        // SAFETY: `ptr` came from `T::into_foreign`.
+        Some(unsafe { T::borrow(ptr.as_ptr()) })
     }
 
     /// Provides a mutable reference to the element at the given index.
     pub fn get_mut(&mut self, index: usize) -> Option<T::BorrowedMut<'_>> {
-        self.load(index, |ptr| {
-            // SAFETY: `ptr` came from `T::into_foreign`.
-            unsafe { T::borrow_mut(ptr.as_ptr()) }
-        })
+        let ptr = self.load(index)?;
+
+        // SAFETY: `ptr` came from `T::into_foreign`.
+        Some(unsafe { T::borrow_mut(ptr.as_ptr()) })
     }
 
     /// Removes and returns the element at the given index.

-- 
2.51.2