rust: block: remove `RawWriter`

`RawWriter` is now dead code, so remove it.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250902-rnull-up-v6-16-v7-9-b5212cc89b98@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

2 files changed, 0 insertions, 57 deletions

diff --git a/rust/kernel/block/mq.rs b/rust/kernel/block/mq.rs
index 831445d37181..98fa0d6bc8f7 100644
--- a/rust/kernel/block/mq.rs
+++ b/rust/kernel/block/mq.rs
@@ -89,7 +89,6 @@
 
 pub mod gen_disk;
 mod operations;
-mod raw_writer;
 mod request;
 mod tag_set;
 
diff --git a/rust/kernel/block/mq/raw_writer.rs b/rust/kernel/block/mq/raw_writer.rs
deleted file mode 100644
index 0aef55703e71..000000000000
--- a/rust/kernel/block/mq/raw_writer.rs
+++ /dev/null
@@ -1,56 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-use core::fmt::{self, Write};
-
-use crate::error::Result;
-use crate::prelude::EINVAL;
-
-/// A mutable reference to a byte buffer where a string can be written into.
-///
-/// # Invariants
-///
-/// `buffer` is always null terminated.
-pub(crate) struct RawWriter<'a> {
-    buffer: &'a mut [u8],
-    pos: usize,
-}
-
-impl<'a> RawWriter<'a> {
-    /// Create a new `RawWriter` instance.
-    fn new(buffer: &'a mut [u8]) -> Result<RawWriter<'a>> {
-        *(buffer.last_mut().ok_or(EINVAL)?) = 0;
-
-        // INVARIANT: We null terminated the buffer above.
-        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>> {
-        Self::new(
-            // SAFETY: the buffer of `a` is valid for read and write as `u8` for
-            // at least `N` bytes.
-            unsafe { core::slice::from_raw_parts_mut(a.as_mut_ptr().cast::<u8>(), N) },
-        )
-    }
-}
-
-impl Write for RawWriter<'_> {
-    fn write_str(&mut self, s: &str) -> fmt::Result {
-        let bytes = s.as_bytes();
-        let len = bytes.len();
-
-        // We do not want to overwrite our null terminator
-        if self.pos + len > self.buffer.len() - 1 {
-            return Err(fmt::Error);
-        }
-
-        // INVARIANT: We are not overwriting the last byte
-        self.buffer[self.pos..self.pos + len].copy_from_slice(bytes);
-
-        self.pos += len;
-
-        Ok(())
-    }
-}