Add ARef::into_raw

[y86-dev]

Add the function into_raw to ARef<T>, the function should:

• consume the ARef<T> by value, but not run the destructor, so you need to mem::forget the ARef<T>.
• return a NonNull<T> or a *mut T, figure out which one works better.
• have an example and some documentation.

Also adjust instances where ARefs are manually forgotten to use this new function.

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This requires submitting a proper patch to the LKML and the Rust for Linux mailing list. Please recall to test your changes, to use a proper title for the commit, to sign your commit under the Developer's Certificate of Origin and so on. Please see https://docs.kernel.org/process/submitting-patches.html and https://rust-for-linux.com/contributing for details.

Please take this issue only if you are new to the kernel development process and you would like to use it as a test to submit your first patch to the kernel.

[Kartik1397]

I'll take this one.

[y86-dev]

Sure!

Note that there currently are no instances of ARefs getting manually forgotten. I created this issue, while reviewing [PATCH 4/7] rust: file: add FileDescriptorReservation. So depending on which thing makes it first into upstream you will or won't have to adjust other stuff.

[Redhawk18]

I'll take this one.

Are you currently working on it?

[Kartik1397]

Yes @Redhawk18, I've the patch ready here, which I'm planning to submit in couple of days once I complete testing of changes in rust/kernel/net/filter.rs and rust/kernel/file.rs files.

[Kartik1397]

Hi @y86-dev, I've drafted a PR for initial review. Please take a look when you can.
I'll send the patch to the mailing list after that.

[vincenzopalazzo]

The PR is sent upstream through ML https://lore.kernel.org/all/20240324231236.145086-1-vincenzopalazzodev@gmail.com/