Re: [PATCH 4/4] rust: sync: lock: use DropGuard

[Boqun Feng <boqun@kernel.org>]

On Sun, Sep 27, 2026 at 01:45:28PM +0300, Mohamed Osama wrote:
> Replace the ScopeGuard usage in the Rust locking implementation with
> DropGuard.
> 
> The guard preserves the existing scope-exit cleanup behavior while using
> the DropGuard API from the Rust kernel memory module.
> 
> Signed-off-by: Mohamed Osama <mohamed.osama189110@gmail.com>

Reviewed-by: Boqun Feng <boqun@kernel.org>

Regards,
Boqun

> ---
>  rust/kernel/sync/lock.rs | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
> index 10b6b5e9b024..15f9cbe76c8d 100644
> --- a/rust/kernel/sync/lock.rs
> +++ b/rust/kernel/sync/lock.rs
> @@ -7,8 +7,9 @@
>  
>  use super::LockClassKey;
>  use crate::{
> +    mem::DropGuard,
>      str::{CStr, CStrExt as _},
> -    types::{NotThreadSafe, Opaque, ScopeGuard},
> +    types::{NotThreadSafe, Opaque},
>  };
>  use core::{cell::UnsafeCell, marker::PhantomPinned, pin::Pin};
>  use pin_init::{pin_data, pin_init, PinInit, Wrapper};
> @@ -242,7 +243,7 @@ pub(crate) fn do_unlocked<U>(&mut self, cb: impl FnOnce() -> U) -> U {
>          // SAFETY: The caller owns the lock, so it is safe to unlock it.
>          unsafe { B::unlock(self.lock.state.get(), &self.state) };
>  
> -        let _relock = ScopeGuard::new(||
> +        let _relock = DropGuard::new((), |_|
>                  // SAFETY: The lock was just unlocked above and is being relocked now.
>                  unsafe { B::relock(self.lock.state.get(), &mut self.state) });
>  
> -- 
> 2.43.0
>