[PATCH 0/3] Remove redundant imports of items re-exported from prelude

[PATCH 0/3] Remove redundant imports of items re-exported from prelude

[Gary Guo]

We had a few occurrence of these redundant imports and up until now they're
mostly checked by human reviews.

I have now implemented a new lint in klint, which is able to spot these and
advice on using prelude imports instead. It caught a few existing cases
that slip through the review. Thus, fix them.

Link: https://github.com/Rust-for-Linux/klint/blob/trunk/doc/not_using_prelude.md

Gary Guo (3):
  gpu: nova-core: remove imports available via prelude
  block: rnull: remove imports available via prelude
  samples: rust: remove imports available via prelude

 drivers/block/rnull/configfs.rs         |  1 -
 drivers/block/rnull/rnull.rs            |  3 ---
 drivers/gpu/nova-core/firmware/fwsec.rs |  1 -
 drivers/gpu/nova-core/firmware/gsp.rs   | 12 +++++-------
 drivers/gpu/nova-core/firmware/riscv.rs |  2 --
 drivers/gpu/nova-core/gsp/sequencer.rs  |  8 +-------
 drivers/gpu/nova-core/sbuffer.rs        |  5 +----
 samples/rust/rust_driver_auxiliary.rs   |  1 -
 samples/rust/rust_misc_device.rs        |  2 --
 samples/rust/rust_print_main.rs         |  2 +-
 10 files changed, 8 insertions(+), 29 deletions(-)


base-commit: a0c666c25aeefd16f4b088c6549a6fb6b65a8a1d
-- 
2.51.2

[PATCH 1/3] gpu: nova-core: remove imports available via prelude

[Gary Guo]

These imports are already in scope by importing `kernel::prelude::*` and
does not need to be imported separately.

Signed-off-by: Gary Guo <gary@garyguo.net>
---
 drivers/gpu/nova-core/firmware/fwsec.rs |  1 -
 drivers/gpu/nova-core/firmware/gsp.rs   | 12 +++++-------
 drivers/gpu/nova-core/firmware/riscv.rs |  2 --
 drivers/gpu/nova-core/gsp/sequencer.rs  |  8 +-------
 drivers/gpu/nova-core/sbuffer.rs        |  5 +----
 5 files changed, 7 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/nova-core/firmware/fwsec.rs b/drivers/gpu/nova-core/firmware/fwsec.rs
index b28e34d279f4..dd2d1f0f24ed 100644
--- a/drivers/gpu/nova-core/firmware/fwsec.rs
+++ b/drivers/gpu/nova-core/firmware/fwsec.rs
@@ -12,7 +12,6 @@
 
 use core::{
     marker::PhantomData,
-    mem::size_of,
     ops::Deref, //
 };
 
diff --git a/drivers/gpu/nova-core/firmware/gsp.rs b/drivers/gpu/nova-core/firmware/gsp.rs
index 1025b7f746eb..f0f18166849e 100644
--- a/drivers/gpu/nova-core/firmware/gsp.rs
+++ b/drivers/gpu/nova-core/firmware/gsp.rs
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
 
-use core::mem::size_of_val;
-
 use kernel::{
     device,
     dma::{
@@ -34,11 +32,11 @@
 /// that scheme before nova-core becomes stable, which means this module will eventually be
 /// removed.
 mod elf {
-    use core::mem::size_of;
-
-    use kernel::bindings;
-    use kernel::str::CStr;
-    use kernel::transmute::FromBytes;
+    use kernel::{
+        bindings,
+        prelude::*,
+        transmute::FromBytes, //
+    };
 
     /// Newtype to provide a [`FromBytes`] implementation.
     #[repr(transparent)]
diff --git a/drivers/gpu/nova-core/firmware/riscv.rs b/drivers/gpu/nova-core/firmware/riscv.rs
index 28dfef63657a..4bdd89bd0757 100644
--- a/drivers/gpu/nova-core/firmware/riscv.rs
+++ b/drivers/gpu/nova-core/firmware/riscv.rs
@@ -3,8 +3,6 @@
 //! Support for firmware binaries designed to run on a RISC-V core. Such firmwares files have a
 //! dedicated header.
 
-use core::mem::size_of;
-
 use kernel::{
     device,
     firmware::Firmware,
diff --git a/drivers/gpu/nova-core/gsp/sequencer.rs b/drivers/gpu/nova-core/gsp/sequencer.rs
index d6c489c39092..c31b245acea3 100644
--- a/drivers/gpu/nova-core/gsp/sequencer.rs
+++ b/drivers/gpu/nova-core/gsp/sequencer.rs
@@ -2,13 +2,7 @@
 
 //! GSP Sequencer implementation for Pre-hopper GSP boot sequence.
 
-use core::{
-    array,
-    mem::{
-        size_of,
-        size_of_val, //
-    },
-};
+use core::array;
 
 use kernel::{
     device,
diff --git a/drivers/gpu/nova-core/sbuffer.rs b/drivers/gpu/nova-core/sbuffer.rs
index 64758b7fae56..3a41d224c77a 100644
--- a/drivers/gpu/nova-core/sbuffer.rs
+++ b/drivers/gpu/nova-core/sbuffer.rs
@@ -2,10 +2,7 @@
 
 use core::ops::Deref;
 
-use kernel::{
-    alloc::KVec,
-    prelude::*, //
-};
+use kernel::prelude::*;
 
 /// A buffer abstraction for discontiguous byte slices.
 ///
-- 
2.51.2

Re: [PATCH 1/3] gpu: nova-core: remove imports available via prelude

[Danilo Krummrich]

On Fri Jan 23, 2026 at 6:19 PM CET, Gary Guo wrote:
> These imports are already in scope by importing `kernel::prelude::*` and
> does not need to be imported separately.
>
> Signed-off-by: Gary Guo <gary@garyguo.net>

I will pick this one up after -rc1 is out.

Re: [PATCH 1/3] gpu: nova-core: remove imports available via prelude

[Danilo Krummrich]

On Sun Jan 25, 2026 at 10:17 PM CET, Danilo Krummrich wrote:
> I will pick this one up after -rc1 is out.

I just checked and there shouldn't be any conflicts, so if you want to pick this
one up as well, please do. :)

Acked-by: Danilo Krummrich <dakr@kernel.org>

Given that klint can do quite some convinient extra checks, should we consider
making it an optional part of the build? Similar to what we do with clippy?

Re: [PATCH 1/3] gpu: nova-core: remove imports available via prelude

[Miguel Ojeda]

On Tue, Jan 27, 2026 at 12:30 PM Danilo Krummrich <dakr@kernel.org> wrote:
>
> I just checked and there shouldn't be any conflicts, so if you want to pick this
> one up as well, please do. :)
>
> Acked-by: Danilo Krummrich <dakr@kernel.org>

Will, do thanks!

> Given that klint can do quite some convinient extra checks, should we consider
> making it an optional part of the build? Similar to what we do with clippy?

Yeah, that is the goal (e.g. `KLINT=1` or similar eventually).

But if someone wants to run it, it is already possible, IIUC Andreas
already did the other day.

To make things easier for developers/maintainers, I asked Nathan the
other day if we could have them in the LLVM+Rust kernel.org
toolchains, and he was supportive on adding it there when Gary is
ready, so it may be straightforward to set up in CIs! :)

(And later on, ideally, even on linux-next when we things are more settled)

Cheers,
Miguel

Re: [PATCH 1/3] gpu: nova-core: remove imports available via prelude

[Miguel Ojeda]

On Sat, Jan 24, 2026 at 6:11 AM Gary Guo <gary@garyguo.net> wrote:
>
> These imports are already in scope by importing `kernel::prelude::*` and
> does not need to be imported separately.
>
> Signed-off-by: Gary Guo <gary@garyguo.net>

Applied to `rust-next` -- thanks everyone!

With this last one done, this series has all been applied.

Cheers,
Miguel

[PATCH 2/3] block: rnull: remove imports available via prelude

[Gary Guo]

These imports are already in scope by importing `kernel::prelude::*` and
does not need to be imported separately.

Signed-off-by: Gary Guo <gary@garyguo.net>
---
 drivers/block/rnull/configfs.rs | 1 -
 drivers/block/rnull/rnull.rs    | 3 ---
 2 files changed, 4 deletions(-)

diff --git a/drivers/block/rnull/configfs.rs b/drivers/block/rnull/configfs.rs
index bfe998d31eb9..7c2eb5c0b722 100644
--- a/drivers/block/rnull/configfs.rs
+++ b/drivers/block/rnull/configfs.rs
@@ -12,7 +12,6 @@
     str::{kstrtobool_bytes, CString},
     sync::Mutex,
 };
-use pin_init::PinInit;
 
 pub(crate) fn subsystem() -> impl PinInit<kernel::configfs::Subsystem<Config>, Error> {
     let item_type = configfs_attrs! {
diff --git a/drivers/block/rnull/rnull.rs b/drivers/block/rnull/rnull.rs
index a9d5e575a2c4..0ca8715febe8 100644
--- a/drivers/block/rnull/rnull.rs
+++ b/drivers/block/rnull/rnull.rs
@@ -14,12 +14,9 @@
             Operations, TagSet,
         },
     },
-    error::Result,
-    pr_info,
     prelude::*,
     sync::{aref::ARef, Arc},
 };
-use pin_init::PinInit;
 
 module! {
     type: NullBlkModule,
-- 
2.51.2

Re: [PATCH 2/3] block: rnull: remove imports available via prelude

[Andreas Hindborg]

"Gary Guo" <gary@garyguo.net> writes:

> These imports are already in scope by importing `kernel::prelude::*` and
> does not need to be imported separately.
>
> Signed-off-by: Gary Guo <gary@garyguo.net>

Acked-by: Andreas Hindborg <a.hindborg@kernel.org>


Best regards,
Andreas Hindborg

Re: [PATCH 2/3] block: rnull: remove imports available via prelude

[Miguel Ojeda]

On Mon, Jan 26, 2026 at 7:27 PM Andreas Hindborg <a.hindborg@kernel.org> wrote:
>
> Acked-by: Andreas Hindborg <a.hindborg@kernel.org>

Is this for Jens or do you want me to pick it up?

Thanks!

Cheers,
Miguel

Re: [PATCH 2/3] block: rnull: remove imports available via prelude

[Andreas Hindborg]

"Miguel Ojeda" <miguel.ojeda.sandonis@gmail.com> writes:

> On Mon, Jan 26, 2026 at 7:27 PM Andreas Hindborg <a.hindborg@kernel.org> wrote:
>>
>> Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
>
> Is this for Jens or do you want me to pick it up?

I think Jens is supposed to pick the block patches.


Best regards,
Andreas Hindborg

[PATCH 3/3] samples: rust: remove imports available via prelude

[Gary Guo]

These imports are already in scope by importing `kernel::prelude::*` and
does not need to be imported separately.

Signed-off-by: Gary Guo <gary@garyguo.net>
---
 samples/rust/rust_driver_auxiliary.rs | 1 -
 samples/rust/rust_misc_device.rs      | 2 --
 samples/rust/rust_print_main.rs       | 2 +-
 3 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/samples/rust/rust_driver_auxiliary.rs b/samples/rust/rust_driver_auxiliary.rs
index f148124fe81f..84c2b1045701 100644
--- a/samples/rust/rust_driver_auxiliary.rs
+++ b/samples/rust/rust_driver_auxiliary.rs
@@ -18,7 +18,6 @@
 };
 
 use core::any::TypeId;
-use pin_init::PinInit;
 
 const MODULE_NAME: &CStr = <LocalModule as kernel::ModuleMetadata>::NAME;
 const AUXILIARY_NAME: &CStr = c"auxiliary";
diff --git a/samples/rust/rust_misc_device.rs b/samples/rust/rust_misc_device.rs
index 49dd5814e1ab..87a1fe63533a 100644
--- a/samples/rust/rust_misc_device.rs
+++ b/samples/rust/rust_misc_device.rs
@@ -95,8 +95,6 @@
 //! }
 //! ```
 
-use core::pin::Pin;
-
 use kernel::{
     device::Device,
     fs::{File, Kiocb},
diff --git a/samples/rust/rust_print_main.rs b/samples/rust/rust_print_main.rs
index 4095c72afeab..682207c81fc2 100644
--- a/samples/rust/rust_print_main.rs
+++ b/samples/rust/rust_print_main.rs
@@ -101,7 +101,7 @@ fn drop(&mut self) {
 }
 
 mod trace {
-    use kernel::ffi::c_int;
+    use kernel::prelude::*;
 
     kernel::declare_trace! {
         /// # Safety
-- 
2.51.2

Re: [PATCH 3/3] samples: rust: remove imports available via prelude

[Danilo Krummrich]

On Fri Jan 23, 2026 at 6:19 PM CET, Gary Guo wrote:
>  samples/rust/rust_driver_auxiliary.rs | 1 -

Acked-by: Danilo Krummrich <dakr@kernel.org>

Re: [PATCH 3/3] samples: rust: remove imports available via prelude

[Alice Ryhl]

On Fri, Jan 23, 2026 at 05:19:42PM +0000, Gary Guo wrote:
> These imports are already in scope by importing `kernel::prelude::*` and
> does not need to be imported separately.
> 
> Signed-off-by: Gary Guo <gary@garyguo.net>

Reviewed-by: Alice Ryhl <aliceryhl@google.com>

Re: [PATCH 3/3] samples: rust: remove imports available via prelude

[Miguel Ojeda]

On Sat, Jan 24, 2026 at 6:08 AM Gary Guo <gary@garyguo.net> wrote:
>
>   samples/rust/rust_misc_device.rs      | 2 --

If Greg/Arnd don't say otherwise, I will eventually pick this patch
including the file above, given it is trivial.

Cheers,
Miguel

Re: [PATCH 3/3] samples: rust: remove imports available via prelude

[Greg Kroah-Hartman]

On Mon, Jan 26, 2026 at 04:02:29PM +0100, Miguel Ojeda wrote:
> On Sat, Jan 24, 2026 at 6:08 AM Gary Guo <gary@garyguo.net> wrote:
> >
> >   samples/rust/rust_misc_device.rs      | 2 --
> 
> If Greg/Arnd don't say otherwise, I will eventually pick this patch
> including the file above, given it is trivial.

No objection from me:

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH 3/3] samples: rust: remove imports available via prelude

[Miguel Ojeda]

On Sat, Jan 24, 2026 at 6:08 AM Gary Guo <gary@garyguo.net> wrote:
>
> These imports are already in scope by importing `kernel::prelude::*` and
> does not need to be imported separately.
>
> Signed-off-by: Gary Guo <gary@garyguo.net>

Applied (this one only) to `rust-next` -- thanks everyone!

Cheers,
Miguel

Re: [PATCH 3/3] samples: rust: remove imports available via prelude

[Dirk Behme]

On 27/01/2026 12:10, Miguel Ojeda wrote:
> On Sat, Jan 24, 2026 at 6:08 AM Gary Guo <gary@garyguo.net> wrote:
>>
>> These imports are already in scope by importing `kernel::prelude::*` and
>> does not need to be imported separately.
>>
>> Signed-off-by: Gary Guo <gary@garyguo.net>
> 
> Applied (this one only) to `rust-next` -- thanks everyone!

Having my klint setup running now (many thanks Gary!) on today's 
rust-next [1] I still get

error: this item is available via prelude
   --> samples/rust/rust_driver_auxiliary.rs:12:5
    |
12 |     error::Error,
    |     ^^^^^^^^^^^^
    |
    = help: import with `kernel::prelude::*` instead
    = note: `-D klint::not-using-prelude` implied by `-D warnings`
    = help: to override `-D warnings` add 
`#[allow(klint::not_using_prelude)]`

error: aborting due to 1 previous error

Somehow dropping this was not part of this patch. Not sure why ...

Best regards

Dirk

[1] HEAD is 08afcc38a64c ("Merge patch series "Add support for print 
exactly once"")

Re: [PATCH 3/3] samples: rust: remove imports available via prelude

[Gary Guo]

On Fri Jan 30, 2026 at 12:45 PM GMT, Dirk Behme wrote:
> On 27/01/2026 12:10, Miguel Ojeda wrote:
>> On Sat, Jan 24, 2026 at 6:08 AM Gary Guo <gary@garyguo.net> wrote:
>>>
>>> These imports are already in scope by importing `kernel::prelude::*` and
>>> does not need to be imported separately.
>>>
>>> Signed-off-by: Gary Guo <gary@garyguo.net>
>> 
>> Applied (this one only) to `rust-next` -- thanks everyone!
>
> Having my klint setup running now (many thanks Gary!) on today's 
> rust-next [1] I still get
>
> error: this item is available via prelude
>    --> samples/rust/rust_driver_auxiliary.rs:12:5
>     |
> 12 |     error::Error,
>     |     ^^^^^^^^^^^^
>     |
>     = help: import with `kernel::prelude::*` instead
>     = note: `-D klint::not-using-prelude` implied by `-D warnings`
>     = help: to override `-D warnings` add 
> `#[allow(klint::not_using_prelude)]`
>
> error: aborting due to 1 previous error
>
> Somehow dropping this was not part of this patch. Not sure why ...

It was already dropped in
https://lore.kernel.org/rust-for-linux/20260105142123.95030-1-dakr@kernel.org/

Best,
Gary

>
> Best regards
>
> Dirk
>
> [1] HEAD is 08afcc38a64c ("Merge patch series "Add support for print 
> exactly once"")

Re: [PATCH 0/3] Remove redundant imports of items re-exported from prelude

[Miguel Ojeda]

On Fri, Jan 23, 2026 at 6:22 PM Gary Guo <gary@garyguo.net> wrote:
>
> We had a few occurrence of these redundant imports and up until now they're
> mostly checked by human reviews.
>
> I have now implemented a new lint in klint, which is able to spot these and
> advice on using prelude imports instead. It caught a few existing cases
> that slip through the review. Thus, fix them.
>
> Link: https://github.com/Rust-for-Linux/klint/blob/trunk/doc/not_using_prelude.md

This is great news, thanks Gary.

If others give Acked-bys, I can pick these all, but it may be easier
to pick them independently (for that, the print sample should be split
in principle, but it is so small that Acked-bys may work better for
that last patch).

Cheers,
Miguel

Re: (subset) [PATCH 0/3] Remove redundant imports of items re-exported from prelude

[Jens Axboe]

On Fri, 23 Jan 2026 17:19:39 +0000, Gary Guo wrote:
> We had a few occurrence of these redundant imports and up until now they're
> mostly checked by human reviews.
> 
> I have now implemented a new lint in klint, which is able to spot these and
> advice on using prelude imports instead. It caught a few existing cases
> that slip through the review. Thus, fix them.
> 
> [...]

Applied, thanks!

[2/3] block: rnull: remove imports available via prelude
      commit: b2b2ce870651db659247f34636e6243b4547e8af

Best regards,
-- 
Jens Axboe