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Feedback-ID: iad51458e:Fastmail
Date: Fri, 29 Mar 2024 16:23:42 -0700
From: Boqun Feng <boqun.feng@gmail.com>
To: Wedson Almeida Filho <wedsonaf@gmail.com>
Cc: rust-for-linux@vger.kernel.org, Miguel Ojeda <ojeda@kernel.org>,
	Alex Gaynor <alex.gaynor@gmail.com>, Gary Guo <gary@garyguo.net>,
	=?iso-8859-1?Q?Bj=F6rn?= Roy Baron <bjorn3_gh@protonmail.com>,
	Benno Lossin <benno.lossin@proton.me>,
	Andreas Hindborg <a.hindborg@samsung.com>,
	Alice Ryhl <aliceryhl@google.com>, linux-kernel@vger.kernel.org,
	Wedson Almeida Filho <walmeida@microsoft.com>
Subject: Re: [PATCH v3 00/10] Allocation APIs
Message-ID: <ZgdNfvLWXhHIpWUf@boqun-archlinux>
References: <20240328013603.206764-1-wedsonaf@gmail.com>
 <ZgcHfG5Hdhv39SLU@boqun-archlinux>
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In-Reply-To: <ZgcHfG5Hdhv39SLU@boqun-archlinux>

On Fri, Mar 29, 2024 at 11:25:00AM -0700, Boqun Feng wrote:
> On Wed, Mar 27, 2024 at 10:35:53PM -0300, Wedson Almeida Filho wrote:
> > From: Wedson Almeida Filho <walmeida@microsoft.com>
> > 
> > Revamp how we use the `alloc` crate.
> > 
> > We currently have a fork of the crate with changes to `Vec`; other
> > changes have been upstreamed (to the Rust project). This series removes
> > the fork and exposes all the functionality as extension traits.
> > 
> > Additionally, it also introduces allocation flag parameters to all
> > functions that may result in allocations (e.g., `Box::new`, `Arc::new`,
> > `Vec::push`, etc.) without the `try_` prefix -- the names are available
> > because we build `alloc` with `no_global_oom_handling`.
> > 
> > Lastly, the series also removes our reliance on the `allocator_api`
> > unstable feature.
> > 
> > Long term, we still want to make such functionality available in
> > upstream Rust, but this allows us to make progress now and reduces our
> > maintainance burden.
> > 
> > In summary:
> > 1. Removes `alloc` fork
> > 2. Removes use of `allocator_api` unstable feature
> > 3. Introduces flags (e.g., GFP_KERNEL, GFP_ATOMIC) when allocating
> > 
> > ---
> > 
> 
> FWIW, I've put this into rust-dev:
> 
> 	https://github.com/Rust-for-Linux/linux rust-dev
> 
> a few adjustments are needed to work with other commits that have been
> queued in rust-dev, so I add an commit on the top for everyone's
> reference. (Besides this commit, I also removed all updates to our own
> alloc in Miguel's 1.77.0 compiler version bump patch)
> 
> Regards,
> Boqun

As Miguel pointed out offline, the following is also needed:

diff --git a/rust/kernel/file.rs b/rust/kernel/file.rs
index a5930f0f2bc5..bf68a0ce9f14 100644
--- a/rust/kernel/file.rs
+++ b/rust/kernel/file.rs
@@ -350,7 +350,7 @@ impl DeferredFdCloser {
     pub fn new() -> Result<Self, AllocError> {
         Ok(Self {
             // INVARIANT: The `file` pointer is null, so the type invariant does not apply.
-            inner: Box::new(
+            inner: <Box<_> as BoxExt<_>>::new(
                 DeferredFdCloserInner {
                     twork: mem::MaybeUninit::uninit(),
                     file: core::ptr::null_mut(),