Re: [PATCH] chore(util): minimal Rust build example

[Kent Overstreet <kent.overstreet@linux.dev>]

On Wed, May 10, 2023 at 07:56:07PM +0200, Miguel Ojeda wrote:
> On Tue, May 9, 2023 at 8:07 PM Kent Overstreet
> <kent.overstreet@linux.dev> wrote:
> >
> > So if I'm following, it looks like everything is basically there. It
> > looks like we can add Rust source files to fs/bcachefs/ and have them
> > built as part of the bcachefs module, and calling back and forth just
> > works as expected - nice.
> 
> Indeed, that should work, and it may be useful, though typically you
> will want to avoid crossing the C/Rust boundary all the time, so that
> you can work with Rust types as much as possible.
> 
> For modules/drivers, we provide Rust abstractions for the C APIs so
> that one can write drivers in Rust (and thus use Rust facilities and
> avoid `unsafe` as much as possible), rather than mixing C and Rust
> source code in the "leaves". Perhaps there are some parts within
> bcachefs amenable to a similar approach.

I've been doing the same thing.

Right now in bcachefs-tools we've got two different crates, one for
bcachefs rust code proper and another for bindings, with a build.rs for
bindgen.

Any pointers to how we'll be interacting with bindgen kernel side? We
need to pass it some stuff, see
https://evilpiepirate.org/git/bcachefs-tools.git/tree/rust-src/bch_bindgen/build.rs

> 
> > The kbuild stuff looks nice and clean - congrats to those responsible :)
> 
> Thanks for the kind words, though a rework of how that works is
> planned, so hopefully you will also like the new way too... :)

Can't wait... :)