Benno Lossin <benno.lossin@xxxxxxxxx> writes:
> On 3/13/24 12:05, Andreas Hindborg wrote:> From: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
>>
>> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
>> ---
>> rust/kernel/block/mq/request.rs | 67 ++++++++++++++++++++++++++++++++-
>> 1 file changed, 66 insertions(+), 1 deletion(-)
>>
>> diff --git a/rust/kernel/block/mq/request.rs b/rust/kernel/block/mq/request.rs
>> index cccffde45981..8b7f08f894be 100644
>> --- a/rust/kernel/block/mq/request.rs
>> +++ b/rust/kernel/block/mq/request.rs
>> @@ -4,13 +4,16 @@
>> //!
>> //! C header: [`include/linux/blk-mq.h`](srctree/include/linux/blk-mq.h)
>>
>> +use kernel::hrtimer::RawTimer;
>> +
>> use crate::{
>> bindings,
>> block::mq::Operations,
>> error::{Error, Result},
>> + hrtimer::{HasTimer, TimerCallback},
>> types::{ARef, AlwaysRefCounted, Opaque},
>> };
>> -use core::{ffi::c_void, marker::PhantomData, ops::Deref};
>> +use core::{ffi::c_void, marker::PhantomData, ops::Deref, ptr::NonNull};
>>
>> use crate::block::bio::Bio;
>> use crate::block::bio::BioIterator;
>> @@ -175,6 +178,68 @@ fn deref(&self) -> &Self::Target {
>> }
>> }
>>
>> +impl<T> RawTimer for RequestDataRef<T>
>> +where
>> + T: Operations,
>> + T::RequestData: HasTimer<T::RequestData>,
>> + T::RequestData: Sync,
>> +{
>> + fn schedule(self, expires: u64) {
>> + let self_ptr = self.deref() as *const T::RequestData;
>> + core::mem::forget(self);
>> +
>> + // SAFETY: `self_ptr` is a valid pointer to a `T::RequestData`
>> + let timer_ptr = unsafe { T::RequestData::raw_get_timer(self_ptr) };
>> +
>> + // `Timer` is `repr(transparent)`
>> + let c_timer_ptr = timer_ptr.cast::<bindings::hrtimer>();
>> +
>> + // Schedule the timer - if it is already scheduled it is removed and
>> + // inserted
>> +
>> + // SAFETY: c_timer_ptr points to a valid hrtimer instance that was
>> + // initialized by `hrtimer_init`
>> + unsafe {
>> + bindings::hrtimer_start_range_ns(
>> + c_timer_ptr as *mut _,
>> + expires as i64,
>> + 0,
>> + bindings::hrtimer_mode_HRTIMER_MODE_REL,
>> + );
>> + }
>> + }
>> +}
>> +
>> +impl<T> kernel::hrtimer::RawTimerCallback for RequestDataRef<T>
>> +where
>> + T: Operations,
>> + T: Sync,
>
> Why is this needed? Shouldn't this be `T::RequestData: Sync`?
>
> Is the `run` function below executed on a different thread compared to
> the `schedule` function above?
> If yes, then `T::RequestData` probably also needs to be `Send`.
> You also would need to adjust the bounds in the impl above.
It's a typo, thanks for spotting. It should be `T::RequestData: Sync`.
BR Andreas
