Add a type alias for file offsets, i.e. bindings::loff_t. Trying to
avoid using raw bindings types, this seems to be the better alternative
compared to just using i64.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://patch.msgid.link/20251020222722.240473-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

The `BadFdError` doc comment mentions the `EBADF` constant but does
not currently provide a navigation target for readers of the
generated docs. Turning the references into intra-doc links matches
the rest of the module and makes the documentation easier to
explore.

Suggested-by: Onur Özkan <work@onurozkan.dev>
Link: https://github.com/Rust-for-Linux/linux/issues/1186
Signed-off-by: Tong Li <djfkvcing117@gmail.com>
Reviewed-by: Onur Özkan <work@onurozkan.dev>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Pull rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Derive 'Zeroable' for all structs and unions generated by 'bindgen'
     where possible and corresponding cleanups. To do so, add the
     'pin-init' crate as a dependency to 'bindings' and 'uapi'.

     It also includes its first use in the 'cpufreq' module, with more
     to come in the next cycle.

   - Add warning to the 'rustdoc' target to detect broken 'srctree/'
     links and fix existing cases.

   - Remove support for unused (since v6.16) host '#[test]'s,
     simplifying the 'rusttest' target. Tests should generally run
     within KUnit.

  'kernel' crate:

   - Add 'ptr' module with a new 'Alignment' type, which is always a
     power of two and is used to validate that a given value is a valid
     alignment and to perform masking and alignment operations:

         // Checked at build time.
         assert_eq!(Alignment::new::<16>().as_usize(), 16);

         // Checked at runtime.
         assert_eq!(Alignment::new_checked(15), None);

         assert_eq!(Alignment::of::<u8>().log2(), 0);

         assert_eq!(0x25u8.align_down(Alignment::new::<0x10>()), 0x20);
         assert_eq!(0x5u8.align_up(Alignment::new::<0x10>()), Some(0x10));
         assert_eq!(u8::MAX.align_up(Alignment::new::<0x10>()), None);

     It also includes its first use in Nova.

   - Add 'core::mem::{align,size}_of{,_val}' to the prelude, matching
     Rust 1.80.0.

   - Keep going with the steps on our migration to the standard library
     'core::ffi::CStr' type (use 'kernel::{fmt, prelude::fmt!}' and use
     upstream method names).

   - 'error' module: improve 'Error::from_errno' and 'to_result'
     documentation, including examples/tests.

   - 'sync' module: extend 'aref' submodule documentation now that it
     exists, and more updates to complete the ongoing move of 'ARef' and
     'AlwaysRefCounted' to 'sync::aref'.

   - 'list' module: add an example/test for 'ListLinksSelfPtr' usage.

   - 'alloc' module:

      - Implement 'Box::pin_slice()', which constructs a pinned slice of
        elements.

      - Provide information about the minimum alignment guarantees of
        'Kmalloc', 'Vmalloc' and 'KVmalloc'.

      - Take minimum alignment guarantees of allocators for
        'ForeignOwnable' into account.

      - Remove the 'allocator_test' (including 'Cmalloc').

      - Add doctest for 'Vec::as_slice()'.

      - Constify various methods.

   - 'time' module:

      - Add methods on 'HrTimer' that can only be called with exclusive
        access to an unarmed timer, or from timer callback context.

      - Add arithmetic operations to 'Instant' and 'Delta'.

      - Add a few convenience and access methods to 'HrTimer' and
        'Instant'.

  'macros' crate:

   - Reduce collections in 'quote!' macro.

  And a few other cleanups and improvements"

* tag 'rust-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (58 commits)
  gpu: nova-core: use Alignment for alignment-related operations
  rust: add `Alignment` type
  rust: macros: reduce collections in `quote!` macro
  rust: acpi: use `core::ffi::CStr` method names
  rust: of: use `core::ffi::CStr` method names
  rust: net: use `core::ffi::CStr` method names
  rust: miscdevice: use `core::ffi::CStr` method names
  rust: kunit: use `core::ffi::CStr` method names
  rust: firmware: use `core::ffi::CStr` method names
  rust: drm: use `core::ffi::CStr` method names
  rust: cpufreq: use `core::ffi::CStr` method names
  rust: configfs: use `core::ffi::CStr` method names
  rust: auxiliary: use `core::ffi::CStr` method names
  drm/panic: use `core::ffi::CStr` method names
  rust: device: use `kernel::{fmt,prelude::fmt!}`
  rust: sync: use `kernel::{fmt,prelude::fmt!}`
  rust: seq_file: use `kernel::{fmt,prelude::fmt!}`
  rust: kunit: use `kernel::{fmt,prelude::fmt!}`
  rust: file: use `kernel::{fmt,prelude::fmt!}`
  rust: device: use `kernel::{fmt,prelude::fmt!}`
  ...

Reduce coupling to implementation details of the formatting machinery by
avoiding direct use for `core`'s formatting traits and macros.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Simplifies error handling by replacing the manual check
of the return value with the `to_result` helper.

Signed-off-by: Onur Özkan <work@onurozkan.dev>
Link: https://lore.kernel.org/20250821091001.28563-1-work@onurozkan.dev
Signed-off-by: Christian Brauner <brauner@kernel.org>

Update call sites in the fs subsystem to import `ARef` and
`AlwaysRefCounted` from `sync::aref` instead of `types`.

This aligns with the ongoing effort to move `ARef` and
`AlwaysRefCounted` to sync.

Suggested-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Acked-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com>
Link: https://lore.kernel.org/20250814100101.304408-1-shankari.ak0208@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

In Rust 1.78.0, Clippy introduced the `ref_as_ptr` lint [1]:

> Using `as` casts may result in silently changing mutability or type.

While this doesn't eliminate unchecked `as` conversions, it makes such
conversions easier to scrutinize.  It also has the slight benefit of
removing a degree of freedom on which to bikeshed. Thus apply the
changes and enable the lint -- no functional change intended.

Link: https://rust-lang.github.io/rust-clippy/master/index.html#ref_as_ptr [1]
Suggested-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/all/D8PGG7NTWB6U.3SS3A5LN4XWMN@proton.me/
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250615-ptr-as-ptr-v12-6-f43b024581e8@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

In Rust 1.51.0, Clippy introduced the `ptr_as_ptr` lint [1]:

> Though `as` casts between raw pointers are not terrible,
> `pointer::cast` is safer because it cannot accidentally change the
> pointer's mutability, nor cast the pointer to other types like `usize`.

There are a few classes of changes required:
- Modules generated by bindgen are marked
  `#[allow(clippy::ptr_as_ptr)]`.
- Inferred casts (` as _`) are replaced with `.cast()`.
- Ascribed casts (` as *... T`) are replaced with `.cast::<T>()`.
- Multistep casts from references (` as *const _ as *const T`) are
  replaced with `core::ptr::from_ref(&x).cast()` with or without `::<T>`
  according to the previous rules. The `core::ptr::from_ref` call is
  required because `(x as *const _).cast::<T>()` results in inference
  failure.
- Native literal C strings are replaced with `c_str!().as_char_ptr()`.
- `*mut *mut T as _` is replaced with `let *mut *const T = (*mut *mut
  T)`.cast();` since pointer to pointer can be confusing.

Apply these changes and enable the lint -- no functional change
intended.

Link: https://rust-lang.github.io/rust-clippy/master/index.html#ptr_as_ptr [1]
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250615-ptr-as-ptr-v12-1-f43b024581e8@gmail.com
[ Added `.cast()` for `opp`. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Some of the safety comments in `LocalFile`'s methods incorrectly refer to
the `File` type instead of `LocalFile`, so fix them to use the correct
type.

Also add missing Markdown code spans around lifetimes in the safety
comments, i.e. change 'a to `'a`.

Link: https://github.com/Rust-for-Linux/linux/issues/1165
Signed-off-by: Pekka Ristola <pekkarr@protonmail.com>
Link: https://lore.kernel.org/20250527204636.12573-2-pekkarr@protonmail.com
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Unsafe code in `LocalFile`'s methods assumes that the type has the same
layout as the inner `bindings::file`. This is not guaranteed by the default
struct representation in Rust, but requires specifying the `transparent`
representation.

The `File` struct (which also wraps `bindings::file`) is already marked as
`repr(transparent)`, so this change makes their layouts equivalent.

Fixes: 851849824bb5 ("rust: file: add Rust abstraction for `struct file`")
Closes: https://github.com/Rust-for-Linux/linux/issues/1165
Signed-off-by: Pekka Ristola <pekkarr@protonmail.com>
Link: https://lore.kernel.org/20250527204636.12573-1-pekkarr@protonmail.com
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>