Currently, Revocable::new() only supports infallible PinInit
implementations, i.e. impl PinInit<T, Infallible>.
This has been sufficient so far, since users such as Devres do not
support fallibility.
Since this is about to change, make Revocable::new() generic over the
error type E.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
rust/kernel/devres.rs | 2 +-
rust/kernel/revocable.rs | 7 +++++--
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/rust/kernel/devres.rs b/rust/kernel/devres.rs
index d8bdf2bdb879..a7df9fbd724f 100644
--- a/rust/kernel/devres.rs
+++ b/rust/kernel/devres.rs
@@ -98,7 +98,7 @@ struct DevresInner<T> {
impl<T> DevresInner<T> {
fn new(dev: &Device<Bound>, data: T, flags: Flags) -> Result<Arc<DevresInner<T>>> {
let inner = Arc::pin_init(
- pin_init!( DevresInner {
+ try_pin_init!( DevresInner {
dev: dev.into(),
callback: Self::devres_callback,
data <- Revocable::new(data),
diff --git a/rust/kernel/revocable.rs b/rust/kernel/revocable.rs
index fa1fd70efa27..41b8fe374af6 100644
--- a/rust/kernel/revocable.rs
+++ b/rust/kernel/revocable.rs
@@ -82,8 +82,11 @@ unsafe impl<T: Sync + Send> Sync for Revocable<T> {}
impl<T> Revocable<T> {
/// Creates a new revocable instance of the given data.
- pub fn new(data: impl PinInit<T>) -> impl PinInit<Self> {
- pin_init!(Self {
+ pub fn new<E>(data: impl PinInit<T, E>) -> impl PinInit<Self, Error>
+ where
+ Error: From<E>,
+ {
+ try_pin_init!(Self {
is_available: AtomicBool::new(true),
data <- Opaque::pin_init(data),
})
--
2.49.0On Thu Jun 12, 2025 at 4:51 PM CEST, Danilo Krummrich wrote:
> Currently, Revocable::new() only supports infallible PinInit
> implementations, i.e. impl PinInit<T, Infallible>.
>
> This has been sufficient so far, since users such as Devres do not
> support fallibility.
>
> Since this is about to change, make Revocable::new() generic over the
> error type E.
>
> Signed-off-by: Danilo Krummrich <dakr@kernel.org>
> ---
> rust/kernel/devres.rs | 2 +-
> rust/kernel/revocable.rs | 7 +++++--
> 2 files changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/rust/kernel/devres.rs b/rust/kernel/devres.rs
> index d8bdf2bdb879..a7df9fbd724f 100644
> --- a/rust/kernel/devres.rs
> +++ b/rust/kernel/devres.rs
> @@ -98,7 +98,7 @@ struct DevresInner<T> {
> impl<T> DevresInner<T> {
> fn new(dev: &Device<Bound>, data: T, flags: Flags) -> Result<Arc<DevresInner<T>>> {
> let inner = Arc::pin_init(
> - pin_init!( DevresInner {
> + try_pin_init!( DevresInner {
> dev: dev.into(),
> callback: Self::devres_callback,
> data <- Revocable::new(data),
> diff --git a/rust/kernel/revocable.rs b/rust/kernel/revocable.rs
> index fa1fd70efa27..41b8fe374af6 100644
> --- a/rust/kernel/revocable.rs
> +++ b/rust/kernel/revocable.rs
> @@ -82,8 +82,11 @@ unsafe impl<T: Sync + Send> Sync for Revocable<T> {}
>
> impl<T> Revocable<T> {
> /// Creates a new revocable instance of the given data.
> - pub fn new(data: impl PinInit<T>) -> impl PinInit<Self> {
> - pin_init!(Self {
> + pub fn new<E>(data: impl PinInit<T, E>) -> impl PinInit<Self, Error>
> + where
> + Error: From<E>,
I don't think we need this bound as you don't use it in the function
body.
---
Cheers,
Benno
> + {
> + try_pin_init!(Self {
> is_available: AtomicBool::new(true),
> data <- Opaque::pin_init(data),
> })
On Thu, Jun 12, 2025 at 05:48:36PM +0200, Benno Lossin wrote:
> On Thu Jun 12, 2025 at 4:51 PM CEST, Danilo Krummrich wrote:
> > diff --git a/rust/kernel/revocable.rs b/rust/kernel/revocable.rs
> > index fa1fd70efa27..41b8fe374af6 100644
> > --- a/rust/kernel/revocable.rs
> > +++ b/rust/kernel/revocable.rs
> > @@ -82,8 +82,11 @@ unsafe impl<T: Sync + Send> Sync for Revocable<T> {}
> >
> > impl<T> Revocable<T> {
> > /// Creates a new revocable instance of the given data.
> > - pub fn new(data: impl PinInit<T>) -> impl PinInit<Self> {
> > - pin_init!(Self {
> > + pub fn new<E>(data: impl PinInit<T, E>) -> impl PinInit<Self, Error>
> > + where
> > + Error: From<E>,
>
> I don't think we need this bound as you don't use it in the function
> body.
I think it's needed by try_pin_init!() below, no?
Without it I get the compilation error in [1].
> > + {
> > + try_pin_init!(Self {
> > is_available: AtomicBool::new(true),
> > data <- Opaque::pin_init(data),
> > })
>
[1]
error[E0277]: `?` couldn't convert the error to `error::Error`
--> rust/kernel/revocable.rs:87:9
|
87 | / try_pin_init!(Self {
88 | | is_available: AtomicBool::new(true),
89 | | data <- Opaque::pin_init(data),
90 | | })
| | ^
| | |
| |__________this can't be annotated with `?` because it has type `Result<_, E>`
| the trait `core::convert::From<E>` is not implemented for `error::Error`
|
= note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
= note: required for `core::result::Result<revocable::Revocable<T>::new::__InitOk, error::Error>` to implement `core::ops::FromResidual<core::result::Result<core::convert::Infallible, E>>`
= note: this error originates in the macro `$crate::__init_internal` which comes from the expansion of the macro `try_pin_init` (in Nightly builds, run with -Z macro-backtrace for more info)
help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
|
83 | impl<T> Revocable<T> where error::Error: core::convert::From<E> {
| ++++++++++++++++++++++++++++++++++++++++++
error[E0277]: the trait bound `impl PinInit<Revocable<T>, Error>: PinInit<Revocable<T>, E>` is not satisfied
--> rust/kernel/revocable.rs:85:48
|
85 | pub fn new<E>(data: impl PinInit<T, E>) -> impl PinInit<Self, E>
| ^^^^^^^^^^^^^^^^^^^^^ the trait `pin_init::PinInit<revocable::Revocable<T>, E>` is not implemented for `impl pin_init::PinInit<revocable::Revocable<T>, error::Error>`
|
= help: the following other types implement trait `pin_init::PinInit<T, E>`:
`core::result::Result<T, E>` implements `pin_init::PinInit<T, E>`
`pin_init::ChainInit<I, F, T, E>` implements `pin_init::PinInit<T, E>`
`pin_init::ChainPinInit<I, F, T, E>` implements `pin_init::PinInit<T, E>`
`pin_init::__internal::AlwaysFail<T>` implements `pin_init::PinInit<T, ()>`
= note: the full name for the type has been written to 'kernel.long-type-441004638990533407.txt'
= note: consider using `--verbose` to print the full type name to the console
On Thu Jun 12, 2025 at 5:58 PM CEST, Danilo Krummrich wrote:
> On Thu, Jun 12, 2025 at 05:48:36PM +0200, Benno Lossin wrote:
>> On Thu Jun 12, 2025 at 4:51 PM CEST, Danilo Krummrich wrote:
>> > diff --git a/rust/kernel/revocable.rs b/rust/kernel/revocable.rs
>> > index fa1fd70efa27..41b8fe374af6 100644
>> > --- a/rust/kernel/revocable.rs
>> > +++ b/rust/kernel/revocable.rs
>> > @@ -82,8 +82,11 @@ unsafe impl<T: Sync + Send> Sync for Revocable<T> {}
>> >
>> > impl<T> Revocable<T> {
>> > /// Creates a new revocable instance of the given data.
>> > - pub fn new(data: impl PinInit<T>) -> impl PinInit<Self> {
>> > - pin_init!(Self {
>> > + pub fn new<E>(data: impl PinInit<T, E>) -> impl PinInit<Self, Error>
>> > + where
>> > + Error: From<E>,
>>
>> I don't think we need this bound as you don't use it in the function
>> body.
>
> I think it's needed by try_pin_init!() below, no?
>
> Without it I get the compilation error in [1].
>
>> > + {
>> > + try_pin_init!(Self {
>> > is_available: AtomicBool::new(true),
>> > data <- Opaque::pin_init(data),
>> > })
Does it work with this?
try_pin_init!(Self {
is_available: AtomicBool::new(true),
data <- Opaque::pin_init(data),
}? E)
---
Cheers,
Benno
>>
>
> [1]
>
> error[E0277]: `?` couldn't convert the error to `error::Error`
> --> rust/kernel/revocable.rs:87:9
> |
> 87 | / try_pin_init!(Self {
> 88 | | is_available: AtomicBool::new(true),
> 89 | | data <- Opaque::pin_init(data),
> 90 | | })
> | | ^
> | | |
> | |__________this can't be annotated with `?` because it has type `Result<_, E>`
> | the trait `core::convert::From<E>` is not implemented for `error::Error`
> |
> = note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
> = note: required for `core::result::Result<revocable::Revocable<T>::new::__InitOk, error::Error>` to implement `core::ops::FromResidual<core::result::Result<core::convert::Infallible, E>>`
> = note: this error originates in the macro `$crate::__init_internal` which comes from the expansion of the macro `try_pin_init` (in Nightly builds, run with -Z macro-backtrace for more info)
> help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
> |
> 83 | impl<T> Revocable<T> where error::Error: core::convert::From<E> {
> | ++++++++++++++++++++++++++++++++++++++++++
>
> error[E0277]: the trait bound `impl PinInit<Revocable<T>, Error>: PinInit<Revocable<T>, E>` is not satisfied
> --> rust/kernel/revocable.rs:85:48
> |
> 85 | pub fn new<E>(data: impl PinInit<T, E>) -> impl PinInit<Self, E>
> | ^^^^^^^^^^^^^^^^^^^^^ the trait `pin_init::PinInit<revocable::Revocable<T>, E>` is not implemented for `impl pin_init::PinInit<revocable::Revocable<T>, error::Error>`
> |
> = help: the following other types implement trait `pin_init::PinInit<T, E>`:
> `core::result::Result<T, E>` implements `pin_init::PinInit<T, E>`
> `pin_init::ChainInit<I, F, T, E>` implements `pin_init::PinInit<T, E>`
> `pin_init::ChainPinInit<I, F, T, E>` implements `pin_init::PinInit<T, E>`
> `pin_init::__internal::AlwaysFail<T>` implements `pin_init::PinInit<T, ()>`
> = note: the full name for the type has been written to 'kernel.long-type-441004638990533407.txt'
> = note: consider using `--verbose` to print the full type name to the console
On Thu, Jun 12, 2025 at 06:17:40PM +0200, Benno Lossin wrote:
> On Thu Jun 12, 2025 at 5:58 PM CEST, Danilo Krummrich wrote:
> > On Thu, Jun 12, 2025 at 05:48:36PM +0200, Benno Lossin wrote:
> >> On Thu Jun 12, 2025 at 4:51 PM CEST, Danilo Krummrich wrote:
> >> > diff --git a/rust/kernel/revocable.rs b/rust/kernel/revocable.rs
> >> > index fa1fd70efa27..41b8fe374af6 100644
> >> > --- a/rust/kernel/revocable.rs
> >> > +++ b/rust/kernel/revocable.rs
> >> > @@ -82,8 +82,11 @@ unsafe impl<T: Sync + Send> Sync for Revocable<T> {}
> >> >
> >> > impl<T> Revocable<T> {
> >> > /// Creates a new revocable instance of the given data.
> >> > - pub fn new(data: impl PinInit<T>) -> impl PinInit<Self> {
> >> > - pin_init!(Self {
> >> > + pub fn new<E>(data: impl PinInit<T, E>) -> impl PinInit<Self, Error>
> >> > + where
> >> > + Error: From<E>,
> >>
> >> I don't think we need this bound as you don't use it in the function
> >> body.
> >
> > I think it's needed by try_pin_init!() below, no?
> >
> > Without it I get the compilation error in [1].
> >
> >> > + {
> >> > + try_pin_init!(Self {
> >> > is_available: AtomicBool::new(true),
> >> > data <- Opaque::pin_init(data),
> >> > })
>
> Does it work with this?
>
> try_pin_init!(Self {
> is_available: AtomicBool::new(true),
> data <- Opaque::pin_init(data),
> }? E)
Yes, it does -- thanks!
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