Re: [PATCH 09/10] rust: init: update `init` module to take allocation flags

Wedson Almeida Filho
2024-03-27T02:17:42Z

On Tue, 26 Mar 2024 at 11:08, Benno Lossin <benno.lossin@proton.me> wrote:
>
> On 25.03.24 20:54, Wedson Almeida Filho wrote:
> > From: Wedson Almeida Filho <walmeida@microsoft.com>
> >
> > This is the last component in the conversion for allocators to take
> > allocation flags as parameters.
> >
> > Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
> > ---
> > rust/kernel/init.rs | 49 ++++++++++++++++---------------
> > rust/kernel/sync/arc.rs | 17 ++++++-----
> > rust/kernel/sync/condvar.rs | 2 +-
> > rust/kernel/sync/lock/mutex.rs | 2 +-
> > rust/kernel/sync/lock/spinlock.rs | 2 +-
> > rust/kernel/workqueue.rs | 13 +++++---
> > 6 files changed, 47 insertions(+), 38 deletions(-)
>
> One formatting issue below, with that fixed:
>
> Reviewed-by: Benno Lossin <benno.lossin@proton.me>
>
> > diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
> > index 077200f5350b..af539c5eb4bc 100644
> > --- a/rust/kernel/sync/arc.rs
> > +++ b/rust/kernel/sync/arc.rs
> > @@ -565,13 +565,16 @@ pub fn new(value: T, flags: Flags) -> Result<Self, AllocError> {
> > }
> >
> > /// Tries to allocate a new [`UniqueArc`] instance whose contents are not initialised yet.
> > - pub fn new_uninit(_flags: Flags) -> 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 {
> > + let inner = Box::try_init::<AllocError>(
> > + try_init!(ArcInner {
> > // SAFETY: There are no safety requirements for this FFI call.
> > refcount: Opaque::new(unsafe { bindings::REFCOUNT_INIT(1) }),
> > data <- init::uninit::<T, AllocError>(),
> > - }? AllocError))?;
> > + }? AllocError),
> > + flags,
> > + )?;
>
> The indentation looks wrong, rustfmt sadly cannot handle the pin-init
> macros. This looks better to me:
>
> let inner = Box::try_init::<AllocError>(
> try_init!(ArcInner {
> // SAFETY: There are no safety requirements for this FFI call.
> refcount: Opaque::new(unsafe { bindings::REFCOUNT_INIT(1) }),
> data <- init::uninit::<T, AllocError>(),
> }? AllocError),
> flags,
> )?;

I remember trying to rearrange this and `rustfmtcheck` not liking it
but it seems to be happy with your suggestion.

Applying it in v2.

> --
> Cheers,
> Benno
>
> > Ok(UniqueArc {
> > // INVARIANT: The newly-created object has a refcount of 1.
> > // SAFETY: The pointer from the `Box` is valid.