Merge branch 'rust' into file-open

MAINTAINERS

@@ -15550,6 +15550,7 @@ F:	drivers/infiniband/ulp/rtrs/
 RUST
 M:	Miguel Ojeda <[email protected]>
 M:	Alex Gaynor <[email protected]>
+M:	Wedson Almeida Filho <[email protected]>
 L:	[email protected]
 S:	Maintained
 W:	https://github.com/Rust-for-Linux/linux

drivers/char/rust_example.rs

@@ -205,7 +205,7 @@ impl KernelModule for RustExample {
             {
                 let mut guard = data.lock();
                 while *guard != 10 {
-                    cv.wait(&mut guard);
+                    let _ = cv.wait(&mut guard);
                 }
             }
             cv.notify_one();
@@ -227,7 +227,7 @@ impl KernelModule for RustExample {
             {
                 let mut guard = data.lock();
                 while *guard != 10 {
-                    cv.wait(&mut guard);
+                    let _ = cv.wait(&mut guard);
                 }
             }
             cv.notify_one();

rust/kernel/file_operations.rs

@@ -447,8 +447,9 @@ pub trait FileOpener<T: ?Sized>: FileOperations {
 /// You implement this trait whenever you would create a `struct file_operations`.
 ///
 /// File descriptors may be used from multiple threads/processes concurrently, so your type must be
-/// [`Sync`].
-pub trait FileOperations: Sync + Sized {
+/// [`Sync`]. It must also be [`Send`] because [`FileOperations::release`] will be called from the
+/// thread that decrements that associated file's refcount to zero.
+pub trait FileOperations: Send + Sync + Sized {
     /// The methods to use to populate [`struct file_operations`].
     const TO_USE: ToUse;
 

rust/kernel/sync/condvar.rs

@@ -64,6 +64,7 @@ impl CondVar {
     /// [`CondVar::notify_all`], or when the thread receives a signal.
     ///
     /// Returns whether there is a signal pending.
+    #[must_use = "wait returns if a signal is pending, so the caller must check the return value"]
     pub fn wait<L: Lock>(&self, guard: &mut Guard<L>) -> bool {
         let lock = guard.lock;
         let mut wait = MaybeUninit::<bindings::wait_queue_entry>::uninit();