Commit c3a54220 authored by Andreas Hindborg's avatar Andreas Hindborg Committed by Jens Axboe
Browse files

rust: block: use `NullTerminatedFormatter` 



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.

Reviewed-by: default avatarAlice Ryhl <aliceryhl@google.com>
Reviewed-by: default avatarDaniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: default avatarAndreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250902-rnull-up-v6-16-v7-8-b5212cc89b98@kernel.org


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f4b72f15

rust/kernel/block/mq/gen_disk.rs

+7 −5
Original line number Diff line number Diff line
@@ -7,9 +7,11 @@ 


use crate::{

    bindings,

    block::mq::{raw_writer::RawWriter, Operations, TagSet},

    block::mq::{Operations, TagSet},

    error::{self, from_err_ptr, Result},

    prelude::*,

    static_lock_class,

    str::NullTerminatedFormatter,

    sync::Arc,

};

use core::fmt::{self, Write};
@@ -143,14 +145,14 @@ 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::new(

            // 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(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

rust/kernel/block/mq/raw_writer.rs

+1 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ fn new(buffer: &'a mut [u8]) -> Result<RawWriter<'a>> { 
        Ok(Self { buffer, pos: 0 })

    }



    #[expect(dead_code)]

    pub(crate) fn from_array<const N: usize>(

        a: &'a mut [crate::ffi::c_char; N],

    ) -> Result<RawWriter<'a>> {

rust/kernel/str.rs

+0 −1
Original line number Diff line number Diff line
@@ -886,7 +886,6 @@ pub(crate) struct NullTerminatedFormatter<'a> { 


impl<'a> NullTerminatedFormatter<'a> {

    /// Create a new [`Self`] instance.

    #[expect(dead_code)]

    pub(crate) fn new(buffer: &'a mut [u8]) -> Option<NullTerminatedFormatter<'a>> {

        *(buffer.first_mut()?) = 0;