From nobody Fri Oct 10 03:59:40 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4A5D32F363D; Mon, 16 Jun 2025 13:26:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750080384; cv=none; b=XALtYd1x49SEYHeAxny0qPq5FXglJozvkIOd68aTQvaKuVGBY6m5JvRoXuc2Ra18llKaMVW+45CjVgVucvojNccxVZgeoNh9E69FuXBzbDcZ+tynArb8seakyQjx2rpg2JxqLDo2zoX5d2Q4OtfmPE2rBvuhZ5rFraCAIk9keWs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750080384; c=relaxed/simple; bh=Xy4pDJyFz8OGfWuNES6lZszWTLpneVMuG7SL/mculR4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=kr9kuAWfruVAAQZ8WhQizOYcLoZr7y+GLNlDehZr+5P9nXu6ctOzt0LX3fGzwo3dQNLLQH23vDGGTq5yUkB/10X8pXZbqFU8nOv2tCDNuWD0VOa+cP9feBXpoyWVnRLeh26nmU/lmrfC6Ng/9TrmcpmIzqAT4Uwi8/eKsIxyaZc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VtBvcjrN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VtBvcjrN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C8E2C4CEED; Mon, 16 Jun 2025 13:26:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750080383; bh=Xy4pDJyFz8OGfWuNES6lZszWTLpneVMuG7SL/mculR4=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=VtBvcjrNBhyGSteNt40vjNLy/u3qSJpEeoBRQoSHYBkhNq5nbQ4CK9xSOPHZobf+D xCdzmBbcRgpeHEqVicOx0F6DI4DLXJLwG+xjzv6iP+0ayYpPEURck9XG3XItNPhC+7 BHFfREfiwSFpP9XIteQ1OFHc6Jg2egXRZ8XTb/jemP7dOqHF2gQ+YazPh+qhh5d5+p 8O5GEarGLiqOq4mkQ76KWkFLGkvgfOGkuqN/P0sb+Ju80yU0R5h5ttJ9GUJMqKEs+G LxbHzdkLJpiqams2ENXeGEoyaWF/p/HRZQKzRST8k7T8FFB2mKu14hVTpVYC4z9QQw JXz8gM4+uDCig== From: Andreas Hindborg Date: Mon, 16 Jun 2025 15:23:53 +0200 Subject: [PATCH 3/9] rust: block,core: rename `RawWriter` to `BufferWriter` Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250616-rnull-up-v6-16-v1-3-a4168b8e76b2@kernel.org> References: <20250616-rnull-up-v6-16-v1-0-a4168b8e76b2@kernel.org> In-Reply-To: <20250616-rnull-up-v6-16-v1-0-a4168b8e76b2@kernel.org> To: Boqun Feng , Miguel Ojeda , Alex Gaynor , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Alice Ryhl , Trevor Gross , Danilo Krummrich , Jens Axboe Cc: linux-block@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Andreas Hindborg X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=4734; i=a.hindborg@kernel.org; h=from:subject:message-id; bh=Xy4pDJyFz8OGfWuNES6lZszWTLpneVMuG7SL/mculR4=; b=owEBbQKS/ZANAwAIAeG4Gj55KGN3AcsmYgBoUBsMfSsfIU2x8vir85/W36Zd1c9jT2rWnH4/s 3CWw5F33KqJAjMEAAEIAB0WIQQSwflHVr98KhXWwBLhuBo+eShjdwUCaFAbDAAKCRDhuBo+eShj d7EtD/9fnPiUMZOU1FZDKFyILpEcOaP7FCJ7kn1RrBH8mhYofXPV+7f2z71RnHB0h/bM26cNTZz g3U6tGu0o6MHuSDqGOHXcWyWl45svJqLep7VQ0zVvWYvjhZtvOjvNa243eBZB2BccOsN3AC5e1I qfrsFWbowH8c0lUMbg4ey/S8Hlg/sLbUHZoDVfrUZe6hl12jRRhZ+8hT8X+FXS1x15o8bE0ct/Q JR84tq/w9JaKf3jXseI25yGe+It95ZQQoBn+HzPPJQivjcQlUqM7k7Pw23bO8KM1HwKIZhg0FyI BN2/7WN1mrzwAvAFUoTQx1v87jSAf6hRAnUPp1fbBHF2n373gPOGpHvw8t3jUGGZ6Kv7NDbXitK vdPoJXjhaRdqlhSXN8MT0ORTm6Nf8HkaLxjkW50viGxFxVOLsN3MODxAvanREzNpzPn2T+pBJo8 g1gNEfeYwvKxM6ON17gTwRJ2z22WZcpfn9QBYzQJlwqctSIUv1yuVXHg6E/XbOoPe9an/4tvfRk d24ZJya1C2Al0QGtexJsO6Sl55K0oojp2jowaRJnB8j2noU4kiDxlseEy57u9pMC4LI4ToAD2+h 6TmrM0Zj0A6wpm+95yAvIiR6pKLt+d4X2WMZzMvZSat1yJof2pbowMkyvfKFs+YNFMqEHYUIv4W xSEODMIUN0a2cCg== X-Developer-Key: i=a.hindborg@kernel.org; a=openpgp; fpr=3108C10F46872E248D1FB221376EB100563EF7A7 Rename the `RawWriter` to `BufferWriter`, wihich is a more suitable name. Also move the module from `block` to `str`. The ability to format a string to a byte buffer is something that is not specific to `block`, so there is no reason this code should live in `block`. Signed-off-by: Andreas Hindborg --- `BufferWriter` is used in `rnull` for interacting with `configfs`. --- rust/kernel/block/mq.rs | 1 - rust/kernel/block/mq/gen_disk.rs | 9 +++++---- rust/kernel/str.rs | 3 +++ .../{block/mq/raw_writer.rs =3D> str/buffer_writer.rs} | 17 +++++++++++= ------ 4 files changed, 19 insertions(+), 11 deletions(-) diff --git a/rust/kernel/block/mq.rs b/rust/kernel/block/mq.rs index fb0f393c1cea..faa3ccb5a49a 100644 --- a/rust/kernel/block/mq.rs +++ b/rust/kernel/block/mq.rs @@ -89,7 +89,6 @@ =20 pub mod gen_disk; mod operations; -mod raw_writer; mod request; mod tag_set; =20 diff --git a/rust/kernel/block/mq/gen_disk.rs b/rust/kernel/block/mq/gen_di= sk.rs index cd54cd64ea88..a04b709514ac 100644 --- a/rust/kernel/block/mq/gen_disk.rs +++ b/rust/kernel/block/mq/gen_disk.rs @@ -5,10 +5,11 @@ //! C header: [`include/linux/blkdev.h`](srctree/include/linux/blkdev.h) //! C header: [`include/linux/blk_mq.h`](srctree/include/linux/blk_mq.h) =20 -use crate::block::mq::{raw_writer::RawWriter, Operations, TagSet}; +use crate::block::mq::{Operations, TagSet}; use crate::{bindings, error::from_err_ptr, error::Result, sync::Arc}; use crate::{error, static_lock_class}; use core::fmt::{self, Write}; +use kernel::str::BufferWriter; =20 /// A builder for [`GenDisk`]. /// @@ -139,14 +140,14 @@ pub fn build( // SAFETY: `gendisk` is a valid pointer as we initialized it above unsafe { (*gendisk).fops =3D &TABLE }; =20 - let mut raw_writer =3D RawWriter::from_array( + let mut writer =3D BufferWriter::from_array( // SAFETY: `gendisk` points to a valid and initialized instanc= e. We // have exclusive access, since the disk is not added to the V= FS // yet. unsafe { &mut (*gendisk).disk_name }, )?; - raw_writer.write_fmt(name)?; - raw_writer.write_char('\0')?; + writer.write_fmt(name)?; + writer.write_char('\0')?; =20 // SAFETY: `gendisk` points to a valid and initialized instance of // `struct gendisk`. `set_capacity` takes a lock to synchronize th= is diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index a927db8e079c..050793fb7d3a 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -936,3 +936,6 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Resul= t { macro_rules! fmt { ($($f:tt)*) =3D> ( ::core::format_args!($($f)*) ) } + +mod buffer_writer; +pub use buffer_writer::BufferWriter; diff --git a/rust/kernel/block/mq/raw_writer.rs b/rust/kernel/str/buffer_wr= iter.rs similarity index 77% rename from rust/kernel/block/mq/raw_writer.rs rename to rust/kernel/str/buffer_writer.rs index 7e2159e4f6a6..364842a6cff8 100644 --- a/rust/kernel/block/mq/raw_writer.rs +++ b/rust/kernel/str/buffer_writer.rs @@ -10,14 +10,14 @@ /// # Invariants /// /// `buffer` is always null terminated. -pub(crate) struct RawWriter<'a> { +pub struct BufferWriter<'a> { buffer: &'a mut [u8], pos: usize, } =20 -impl<'a> RawWriter<'a> { - /// Create a new `RawWriter` instance. - fn new(buffer: &'a mut [u8]) -> Result> { +impl<'a> BufferWriter<'a> { + /// Create a new [`Self`] instance. + pub fn new(buffer: &'a mut [u8]) -> Result> { *(buffer.last_mut().ok_or(EINVAL)?) =3D 0; =20 // INVARIANT: We null terminated the buffer above. @@ -26,16 +26,21 @@ fn new(buffer: &'a mut [u8]) -> Result> { =20 pub(crate) fn from_array( a: &'a mut [crate::ffi::c_char; N], - ) -> Result> { + ) -> Result> { Self::new( // SAFETY: the buffer of `a` is valid for read and write as `u= 8` for // at least `N` bytes. unsafe { core::slice::from_raw_parts_mut(a.as_mut_ptr().cast::= (), N) }, ) } + + /// Return the position of the write pointer in the underlying buffer. + pub fn pos(&self) -> usize { + self.pos + } } =20 -impl Write for RawWriter<'_> { +impl Write for BufferWriter<'_> { fn write_str(&mut self, s: &str) -> fmt::Result { let bytes =3D s.as_bytes(); let len =3D bytes.len(); --=20 2.47.2