On Tue, Jul 08, 2025 at 09:45:00PM +0200, Andreas Hindborg wrote:
> Use the new `NullBorrowFormatter` 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 | 8 ++++----
> rust/kernel/block/mq/raw_writer.rs | 1 +
> rust/kernel/str.rs | 7 -------
> 3 files changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/rust/kernel/block/mq/gen_disk.rs b/rust/kernel/block/mq/gen_disk.rs
> index 679ee1bb21950..e0e42f7028276 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::NullBorrowFormatter,
> sync::Arc,
> };
> use core::fmt::{self, Write};
> @@ -143,14 +144,13 @@ 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 = NullBorrowFormatter::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')?;
> + writer.write_fmt(name)?;
Although this is nicer than the existing code, I wonder if it should
just be a function rather than a whole NullBorrowFormatter struct? Take
a slice and a fmt::Arguments and write it with a nul-terminator. Do you
need anything more complex than what you have here?
Alice
