[PATCH v2 0/2] rust: debugfs: migrate debugfs traits requirements to zerocopy

[Josef Ippisch via B4 Relay]

Migrate `BinaryWriter` and `BinaryReaderMut`'s default implementation's
requirements on T from `kernel::transmute` traits to `zerocopy` traits.

This is part of a bigger migration from rust/kernel/transmute.rs to the
zerocopy crate, see also [1] and [2]

[1] https://github.com/Rust-for-Linux/linux/issues/975
[2] https://github.com/Rust-for-Linux/linux/issues/1241

The crate zerocopy was introduced with

c37398010a05 rust: zerocopy: import crate

This introduced among other things the `FromBytes` and `IntoBytes` traits
that, when derived, do better checks on the actual requirements of the
types they are implemented on than the existing
`kernel::transmute::FromBytes` and `kernel::transmute::AsBytes` traits,
respectively.

This is my first kernel patch so please let me know if I do anything wrong
process wise or regarding some other aspect!

I noticed that we could probably get rid of the `BinaryWriter` and
`BinaryReaderMut` implementations for `Vec` altogether if we implemented
`FromBytes`, `Immutable` and `IntoBytes` for `Vec`.  These are already
implemented for [T] after all. What do you think?

Suggested-by: Joshua Liebow-Feeser <joshlf@xxxxxxxxxx>
Suggested-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
Link: https://github.com/Rust-for-Linux/linux/issues/975
Link: https://github.com/Rust-for-Linux/linux/issues/1241
Signed-off-by: Josef Ippisch <josef.ippisch.dev@xxxxxxxxxxx>
---
Changes in v2:
- Addresses Sashiko AI review's comment about also migrating
  `BinaryReaderMut` to zerocopy to not bifurcate the API requirements of
  debugfs/traits.rs.
- Do not `use zerocopy::{FromBytes, IntoBytes}` as they are part of
  `use kernel::prelude::*`.
- For some reason sending v2 via SMTP server did not reach the mailing
  list.  I apologize if some of you receive this twice now.  I did not
  mark this RESEND because of the email never reaching the mailing list.
- Link to v1: https://patch.msgid.link/20260719-migrate-binarywriter-to-zerocopy-intobytes-v1-0-27ed30512e75@xxxxxxxxxxx

---
Josef Ippisch (2):
      rust: debugfs: migrate debugfs traits requirements to zerocopy
      rust: debugfs: remove unsafe blocks from traits impl for Vec

 rust/kernel/debugfs/traits.rs | 41 +++++++++++------------------------------
 1 file changed, 11 insertions(+), 30 deletions(-)
---
base-commit: 7059bdf4f04a3e14f4fafb3ac35fdca913e3e21a
change-id: 20260719-migrate-binarywriter-to-zerocopy-intobytes-1e8f4ef93a60

Best regards,
--  
Josef Ippisch <josef.ippisch.dev@xxxxxxxxxxx>