Hi Andreas,
> On 11 Jul 2025, at 08:43, Andreas Hindborg <a.hindborg@xxxxxxxxxx> wrote:
>
> Use the new `NullTerminatedFormatter` to write the name of a `GenDisk` to
> the name buffer. This new formatter automatically adds a trailing null
> marker after the written characters, so we don't need to append that at the
> call site any longer.
>
> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx>
> ---
> rust/kernel/block/mq/gen_disk.rs | 11 ++++++-----
> rust/kernel/block/mq/raw_writer.rs | 1 +
> rust/kernel/str.rs | 1 -
> 3 files changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/rust/kernel/block/mq/gen_disk.rs b/rust/kernel/block/mq/gen_disk.rs
> index 679ee1bb2195..39be2a31337f 100644
> --- a/rust/kernel/block/mq/gen_disk.rs
> +++ b/rust/kernel/block/mq/gen_disk.rs
> @@ -7,9 +7,10 @@
>
> use crate::{
> bindings,
> - block::mq::{raw_writer::RawWriter, Operations, TagSet},
> + block::mq::{Operations, TagSet},
> error::{self, from_err_ptr, Result},
> static_lock_class,
> + str::NullTerminatedFormatter,
> sync::Arc,
> };
> use core::fmt::{self, Write};
> @@ -143,14 +144,14 @@ pub fn build<T: Operations>(
> // SAFETY: `gendisk` is a valid pointer as we initialized it above
> unsafe { (*gendisk).fops = &TABLE };
>
> - let mut raw_writer = RawWriter::from_array(
> + let mut writer = NullTerminatedFormatter::from_array(
> // SAFETY: `gendisk` points to a valid and initialized instance. We
> // have exclusive access, since the disk is not added to the VFS
> // yet.
> unsafe { &mut (*gendisk).disk_name },
> - )?;
> - raw_writer.write_fmt(name)?;
> - raw_writer.write_char('\0')?;
> + )
> + .ok_or(error::code::EINVAL)?;
> + writer.write_fmt(name)?;
>
> // SAFETY: `gendisk` points to a valid and initialized instance of
> // `struct gendisk`. `set_capacity` takes a lock to synchronize this
> diff --git a/rust/kernel/block/mq/raw_writer.rs b/rust/kernel/block/mq/raw_writer.rs
> index 7e2159e4f6a6..0aef55703e71 100644
> --- a/rust/kernel/block/mq/raw_writer.rs
> +++ b/rust/kernel/block/mq/raw_writer.rs
> @@ -24,6 +24,7 @@ fn new(buffer: &'a mut [u8]) -> Result<RawWriter<'a>> {
> Ok(Self { buffer, pos: 0 })
> }
>
> + #[expect(dead_code)]
Not sure I understand, is this superseded by..
> pub(crate) fn from_array<const N: usize>(
> a: &'a mut [crate::ffi::c_char; N],
> ) -> Result<RawWriter<'a>> {
> diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
> index c58925438c6e..7396c49174cd 100644
> --- a/rust/kernel/str.rs
> +++ b/rust/kernel/str.rs
> @@ -858,7 +858,6 @@ pub(crate) fn new(buffer: &'a mut [u8]) -> Option<NullTerminatedFormatter<'a>> {
> Some(Self { buffer })
> }
>
> - #[expect(dead_code)]
… this?
> pub(crate) fn from_array<const N: usize>(
> buffer: &'a mut [crate::ffi::c_char; N],
> ) -> Option<NullTerminatedFormatter<'a>> {
>
> --
> 2.47.2
>
>
>
— Daniel
