Re: [PATCH v11 2/7] rust: debugfs: Add support for read-only files

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Sep 10, 2025 at 05:23:26PM +0200, Danilo Krummrich wrote:
> On 9/10/25 5:22 PM, Greg Kroah-Hartman wrote:
> > On Tue, Sep 09, 2025 at 10:29:13AM +0200, Danilo Krummrich wrote:
> >> On Tue Sep 9, 2025 at 9:29 AM CEST, Dirk Behme wrote:
> >>> On 04/09/2025 23:13, Matthew Maurer wrote:
> >>>> +#[cfg(not(CONFIG_DEBUG_FS))]
> >>>> +impl<'b, T: 'b> Scope<T> {
> >>>> +    fn new<E: 'b, F>(data: impl PinInit<T, E> + 'b, init: F) -> impl PinInit<Self, E> + 'b
> >>>> +    where
> >>>> +        F: for<'a> FnOnce(&'a T) -> Entry + 'b,
> >>>
> >>> Inspired by Greg's & Danilo's discussion I tried building with
> >>> CONFIG_DEBUG_FS disabled. And get
> >>>
> >>> error[E0412]: cannot find type `Entry` in this scope
> >>>    --> rust/kernel/debugfs.rs:351:37
> >>>     |
> >>> 351 |         F: for<'a> FnOnce(&'a T) -> Entry + 'b,
> >>>     |                                     ^^^^^ not found in this scope
> >>>
> >>> And giving it some Entry (for my 1.81.0)
> >>>
> >>> error: hidden lifetime parameters in types are deprecated
> >>>    --> rust/kernel/debugfs.rs:352:37
> >>>     |
> >>> 352 |         F: for<'a> FnOnce(&'a T) -> Entry + 'b,
> >>>     |                                     ^^^^^ expected lifetime parameter
> >>
> >> Yeah, I caught this as well and fixed it up on my end with the following diff:
> >>
> >> diff --git a/rust/kernel/debugfs.rs b/rust/kernel/debugfs.rs
> >> index ecfcce845d3f..1f25777743db 100644
> >> --- a/rust/kernel/debugfs.rs
> >> +++ b/rust/kernel/debugfs.rs
> >> @@ -348,7 +348,7 @@ pub struct File<T> {
> >>  impl<'b, T: 'b> Scope<T> {
> >>      fn new<E: 'b, F>(data: impl PinInit<T, E> + 'b, init: F) -> impl PinInit<Self, E> + 'b
> >>      where
> >> -        F: for<'a> FnOnce(&'a T) -> Entry + 'b,
> >> +        F: for<'a> FnOnce(&'a T) + 'b,
> >>      {
> >>          try_pin_init! {
> >>              Self {
> >>
> > 
> > Can you send this as a fix-up patch?
> 
> If you don't mind I would fix this (and one other nit) up on apply. :)

I've pushed these to driver-core-testing if you could fix it up as I
don't know what the other change was?

thanks,

greg k-h