Re: [PATCH] rust: sync: export lock::do_unlocked

[Andreas Hindborg <a.hindborg@kernel.org>]

"Benno Lossin" <lossin@kernel.org> writes:

> On Sun Feb 15, 2026 at 9:15 PM CET, Andreas Hindborg wrote:
>> Export lock::do_unlocked publicly. Add documentation for the method.
>>
>> Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
>
> Reviewed-by: Benno Lossin <lossin@kernel.org>
>
>> ---
>>  rust/kernel/sync/lock.rs | 26 +++++++++++++++++++++++++-
>>  1 file changed, 25 insertions(+), 1 deletion(-)
>>
>> diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
>> index 46a57d1fc309d..f390cd7ba0762 100644
>> --- a/rust/kernel/sync/lock.rs
>> +++ b/rust/kernel/sync/lock.rs
>> @@ -235,7 +235,31 @@ pub fn lock_ref(&self) -> &'a Lock<T, B> {
>>          self.lock
>>      }
>>
>> -    pub(crate) fn do_unlocked<U>(&mut self, cb: impl FnOnce() -> U) -> U {
>> +    /// Temporarily unlock the lock to execute the given closure.
>> +    ///
>> +    /// This method unlocks the lock before calling the closure `cb`, and re-locks it afterwards.
>> +    /// This is useful when you need to perform operations that are not allowed while holding
>> +    /// certain locks, such as allocating memory (which is prohibited while holding a spinlock).
>> +    ///
>> +    /// # Examples
>> +    ///
>> +    /// ```
>> +    /// # use kernel::{new_spinlock, prelude::*};
>> +    /// # use pin_init::stack_pin_init;
>> +    ///
>> +    /// stack_pin_init!{
>> +    ///     let lock = new_spinlock!(())
>> +    /// }
>> +    ///
>> +    /// let mut guard = lock.lock();
>> +    /// let mut buffer = KVec::new();
>> +    /// // Temporarily unlock to allocate memory, which should not be done while holding a spinlock.
>> +    ///  guard.do_unlocked(|| {
>            ^
> Spurious space.

Thanks. Code formatting in comments is a problem in my setup. `rustfmt`
is not much help.


Best regards,
Andreas Hindborg