Re: [PATCH v6 07/10] rust: configfs: use `LocalModule` for `THIS_MODULE`

[Alvin Sun <alvin.sun@linux.dev>]

On 6/26/26 22:41, Gary Guo wrote:
> On Fri Jun 26, 2026 at 3:35 AM BST, Alvin Sun wrote:
>> On 6/25/26 22:40, Gary Guo wrote:
>>> On Wed Jun 24, 2026 at 4:00 PM BST, Alvin Sun wrote:
>>>> Replace the `THIS_MODULE` static reference in the `configfs_attrs!`
>>>> macro with `this_module::<LocalModule>()`, and update
>>>> rnull to import `LocalModule` instead of `THIS_MODULE`, consistent
>>>> with the move of `THIS_MODULE` into the `ModuleMetadata` trait.
>>>>
>>>> Assisted-by: opencode:glm-5.2
>>>> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
>>>> Acked-by: Danilo Krummrich <dakr@kernel.org>
>>>> Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
>>>> ---
>>>>    drivers/block/rnull/configfs.rs | 6 ++----
>>>>    rust/kernel/configfs.rs         | 8 +++++---
>>>>    2 files changed, 7 insertions(+), 7 deletions(-)
>>>>
>>>> diff --git a/drivers/block/rnull/configfs.rs b/drivers/block/rnull/configfs.rs
>>>> index c10a55fc58948..b2547ad1e5ddd 100644
>>>> --- a/drivers/block/rnull/configfs.rs
>>>> +++ b/drivers/block/rnull/configfs.rs
>>>> @@ -1,9 +1,7 @@
>>>>    // SPDX-License-Identifier: GPL-2.0
>>>>    
>>>> -use super::{
>>>> -    NullBlkDevice,
>>>> -    THIS_MODULE, //
>>>> -};
>>>> +use super::NullBlkDevice;
>>>> +use crate::LocalModule;
>>>>    use kernel::{
>>>>        block::mq::gen_disk::{
>>>>            GenDisk,
>>>> diff --git a/rust/kernel/configfs.rs b/rust/kernel/configfs.rs
>>>> index 2339c6467325d..c31d7882e216d 100644
>>>> --- a/rust/kernel/configfs.rs
>>>> +++ b/rust/kernel/configfs.rs
>>>> @@ -875,7 +875,7 @@ fn as_ptr(&self) -> *const bindings::config_item_type {
>>>>    ///                 configfs::Subsystem<Configuration>,
>>>>    ///                 Configuration
>>>>    ///                 >::new_with_child_ctor::<N,Child>(
>>>> -///             &THIS_MODULE,
>>>> +///             ::kernel::module::this_module::<crate::LocalModule>(),
>>>>    ///             &CONFIGURATION_ATTRS
>>>>    ///         );
>>>>    ///
>>>> @@ -1021,7 +1021,8 @@ macro_rules! configfs_attrs {
>>>>    
>>>>                        static [< $data:upper _TPE >] : $crate::configfs::ItemType<$container, $data>  =
>>>>                            $crate::configfs::ItemType::<$container, $data>::new::<N>(
>>>> -                            &THIS_MODULE, &[<$ data:upper _ATTRS >]
>>>> +                            $crate::module::this_module::<LocalModule>(),
>>> ^ You only changed one single place. This is still plain `LocalModule`.
>> Initially I wrote it as `crate::LocalModule`, but clippy warned about it. So
>> instead of putting the crate path in the macro body, I added `use
>> crate::LocalModule` in the calling file.
>>
>> ```
>> warning: `crate` references the macro call's crate
>>       --> rust/kernel/configfs.rs:1024:59
>>        |
>> 1024 | ...  $crate::module::this_module::<crate::LocalModule>(),
>>        |                                                     ^^^^^ help:
>> to reference the macro definition's crate, use: `$crate`
>>        |
>>        = help: for further information visit
>> https://rust-lang.github.io/rust-clippy/rust-1.94.0/index.html#crate_in_macro_def
>>        = note: `-W clippy::crate-in-macro-def` implied by `-W clippy::all`
>>        = help: to override `-W clippy::all` add
>> `#[allow(clippy::crate_in_macro_def)]`
>>
>> warning: 1 warning emitted
>> ```
> Clippy has a point about `crate::` being usually wrong in macros, but it is what
> we actually want here, so obviously you should allow the warning.
>
> It is the exact same case in `vtable` macro, just that Clippy is unable to check
> proc macros!

Thanks for the detailed explanation.

I specifically searched for issues related to `crate_in_macro_def`, and 
this information is very useful to me.

Best regards,

Alvin

>
> Best,
> Gary
>
>> Alternatively, `#[allow(clippy::crate_in_macro_def)]` could be added on
>> the macro
>> definition. Would you suggest that approach?