[PATCH 08/10] rust: sync: update `Arc` and `UniqueArc` to take allocation flags

Wedson Almeida Filho
2024-03-25T19:55:35Z

From: Wedson Almeida Filho <walmeida@microsoft.com>

We also remove the `try_` prefix to align with how `Box` and `Vec` are
providing methods now.

`init` is temporarily updated with uses of GFP_KERNEL. These will be
updated in a subsequent patch to take flags as well.

Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
---
rust/kernel/init.rs | 4 ++--
rust/kernel/sync/arc.rs | 28 ++++++++++++++--------------
samples/rust/rust_print.rs | 4 ++--
3 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index 0d956934eaa4..c8b2f9774a39 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -1189,7 +1189,7 @@ fn try_pin_init<E>(init: impl PinInit<T, E>) -> Result<Pin<Self>, E>
where
E: From<AllocError>,
{
- let mut this = UniqueArc::try_new_uninit()?;
+ let mut this = UniqueArc::new_uninit(GFP_KERNEL)?;
let slot = this.as_mut_ptr();
// SAFETY: When init errors/panics, slot will get deallocated but not dropped,
// slot is valid and will not be moved, because we pin it later.
@@ -1203,7 +1203,7 @@ fn try_init<E>(init: impl Init<T, E>) -> Result<Self, E>
where
E: From<AllocError>,
{
- let mut this = UniqueArc::try_new_uninit()?;
+ let mut this = UniqueArc::new_uninit(GFP_KERNEL)?;
let slot = this.as_mut_ptr();
// SAFETY: When init errors/panics, slot will get deallocated but not dropped,
// slot is valid.
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index f0a5aed69693..077200f5350b 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -16,7 +16,7 @@
//! [`Arc`]: https://doc.rust-lang.org/std/sync/struct.Arc.html

use crate::{
- alloc::{boxext::BoxExt, flags::*},
+ alloc::{boxext::BoxExt, Flags},
bindings,
error::{self, Error},
init::{self, InPlaceInit, Init, PinInit},
@@ -58,7 +58,7 @@
/// }
///
/// // Create a refcounted instance of `Example`.
-/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
+/// let obj = Arc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
///
/// // Get a new pointer to `obj` and increment the refcount.
/// let cloned = obj.clone();
@@ -97,7 +97,7 @@
/// }
/// }
///
-/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
+/// let obj = Arc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
/// obj.use_reference();
/// obj.take_over();
/// # Ok::<(), Error>(())
@@ -120,7 +120,7 @@
/// impl MyTrait for Example {}
///
/// // `obj` has type `Arc<Example>`.
-/// let obj: Arc<Example> = Arc::try_new(Example)?;
+/// let obj: Arc<Example> = Arc::new(Example, GFP_KERNEL)?;
///
/// // `coerced` has type `Arc<dyn MyTrait>`.
/// let coerced: Arc<dyn MyTrait> = obj;
@@ -163,7 +163,7 @@ unsafe impl<T: ?Sized + Sync + Send> Sync for Arc<T> {}

impl<T> Arc<T> {
/// Constructs a new reference counted instance of `T`.
- pub fn try_new(contents: T) -> Result<Self, AllocError> {
+ pub fn new(contents: T, flags: Flags) -> Result<Self, AllocError> {
// INVARIANT: The refcount is initialised to a non-zero value.
let value = ArcInner {
// SAFETY: There are no safety requirements for this FFI call.
@@ -171,7 +171,7 @@ pub fn try_new(contents: T) -> Result<Self, AllocError> {
data: contents,
};

- let inner = <Box<_> as BoxExt<_>>::new(value, GFP_KERNEL)?;
+ let inner = <Box<_> as BoxExt<_>>::new(value, flags)?;

// SAFETY: We just created `inner` with a reference count of 1, which is owned by the new
// `Arc` object.
@@ -388,7 +388,7 @@ fn from(item: Pin<UniqueArc<T>>) -> Self {
/// e.into()
/// }
///
-/// let obj = Arc::try_new(Example)?;
+/// let obj = Arc::new(Example, GFP_KERNEL)?;
/// let cloned = do_something(obj.as_arc_borrow());
///
/// // Assert that both `obj` and `cloned` point to the same underlying object.
@@ -412,7 +412,7 @@ fn from(item: Pin<UniqueArc<T>>) -> Self {
/// }
/// }
///
-/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
+/// let obj = Arc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
/// obj.as_arc_borrow().use_reference();
/// # Ok::<(), Error>(())
/// ```
@@ -500,7 +500,7 @@ fn deref(&self) -> &Self::Target {
/// }
///
/// fn test() -> Result<Arc<Example>> {
-/// let mut x = UniqueArc::try_new(Example { a: 10, b: 20 })?;
+/// let mut x = UniqueArc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
/// x.a += 1;
/// x.b += 1;
/// Ok(x.into())
@@ -523,7 +523,7 @@ fn deref(&self) -> &Self::Target {
/// }
///
/// fn test() -> Result<Arc<Example>> {
-/// let x = UniqueArc::try_new_uninit()?;
+/// let x = UniqueArc::new_uninit(GFP_KERNEL)?;
/// Ok(x.write(Example { a: 10, b: 20 }).into())
/// }
///
@@ -543,7 +543,7 @@ fn deref(&self) -> &Self::Target {
/// }
///
/// fn test() -> Result<Arc<Example>> {
-/// let mut pinned = Pin::from(UniqueArc::try_new(Example { a: 10, b: 20 })?);
+/// let mut pinned = Pin::from(UniqueArc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?);
/// // We can modify `pinned` because it is `Unpin`.
/// pinned.as_mut().a += 1;
/// Ok(pinned.into())
@@ -557,15 +557,15 @@ pub struct UniqueArc<T: ?Sized> {

impl<T> UniqueArc<T> {
/// Tries to allocate a new [`UniqueArc`] instance.
- pub fn try_new(value: T) -> Result<Self, AllocError> {
+ pub fn new(value: T, flags: Flags) -> Result<Self, AllocError> {
Ok(Self {
// INVARIANT: The newly-created object has a refcount of 1.
- inner: Arc::try_new(value)?,
+ inner: Arc::new(value, flags)?,
})
}

/// Tries to allocate a new [`UniqueArc`] instance whose contents are not initialised yet.
- pub fn try_new_uninit() -> Result<UniqueArc<MaybeUninit<T>>, AllocError> {
+ pub fn new_uninit(_flags: Flags) -> Result<UniqueArc<MaybeUninit<T>>, AllocError> {
// INVARIANT: The refcount is initialised to a non-zero value.
let inner = Box::try_init::<AllocError>(try_init!(ArcInner {
// SAFETY: There are no safety requirements for this FFI call.
diff --git a/samples/rust/rust_print.rs b/samples/rust/rust_print.rs
index 67ed8ebf8e8e..6eabb0d79ea3 100644
--- a/samples/rust/rust_print.rs
+++ b/samples/rust/rust_print.rs
@@ -18,8 +18,8 @@
fn arc_print() -> Result {
use kernel::sync::*;

- let a = Arc::try_new(1)?;
- let b = UniqueArc::try_new("hello, world")?;
+ let a = Arc::new(1, GFP_KERNEL)?;
+ let b = UniqueArc::new("hello, world", GFP_KERNEL)?;

// Prints the value of data in `a`.
pr_info!("{}", a);
--
2.34.1