From nobody Sat Feb 7 17:43:25 2026 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 124D725740; Mon, 12 Feb 2024 14:13:22 +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=1707747203; cv=none; b=BqTR5AdOKtqw0zagNxjq26utXqo4bQhHwAgtz0CxpNCkXPOtW2ps9qPwqvSlEv+ZRnOhOevtSuAsTMgU9yYChnrj54rXN6gtpUhXmbOpP3FbySFGEhupdCR0WYDtpNRjiJQ51FSd6DMvjyfuYv3W7jpSSGFpasos0T0YI4s8R5Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707747203; c=relaxed/simple; bh=MRoovGwQKiJetb5e8HWBFCiVQj6gfEzlk51Wmz0W+y4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=E9uyfrYgVkHaha4kV7ZVwkmdMq+2NHO86+5POTFhjJxjrIbC2gV7J2IMuPf8qWp6+D+6YDbxu5zjoY78mH5Z6hHVMEtGBhwE/EJYQx1nUlRHrWvAbl8COyoLz4tQrU8+T9H2nL1q8Yt9tueo5G/N3raWJ2nhD010AMNep/RS+UQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QXjPeDXT; 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="QXjPeDXT" Received: by smtp.kernel.org (Postfix) with ESMTPS id 6FE8FC433F1; Mon, 12 Feb 2024 14:13:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707747202; bh=MRoovGwQKiJetb5e8HWBFCiVQj6gfEzlk51Wmz0W+y4=; h=From:Date:Subject:To:Cc:Reply-To:From; b=QXjPeDXT5ZZSDYX55tztYDpV5rZooJplFHdHa0UOVPBwQJlDvuy3VAi+Jcvf9Hsy2 xvz2GmZKdWhJ80Wbm+Wk6iO0p2toyQbIiIufcvQ23RgJLG6SnmzhJ417caBIJXqGEW s7xegs6IZ+Y8tdlGl2VoizIdhfipW6iwc0sseWVFAlyBrHmBfBuOlRfCsYoFuNZ49W qWTKVo6g4+e0YN0AI2tVxLVjngOG/pjG97JrEzN54iylXD5XfUDCQg62QoKENcGVSj Dry8pii2TMAKWr8RcZdOe5zdRG8LA5qJ91cGLSVRj/tz3sXl2AIZHvZZ9vWK2m7aqO e26Vt6V6203oQ== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B3FBC48297; Mon, 12 Feb 2024 14:13:22 +0000 (UTC) From: Mathys-Gasnier via B4 Relay Date: Mon, 12 Feb 2024 15:13:22 +0100 Subject: [PATCH v2] rust: locks: Add `get_mut` method to `Lock` 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: <20240212-rust-locks-get-mut-v2-1-5ccd34c2b70b@gmail.com> X-B4-Tracking: v=1; b=H4sIAIEnymUC/22NQQ6CMBBFr0Jm7ZhOqUFdeQ/DgpQBJgI1bWk0h LtbcevyveS/v0JgLxzgWqzgOUkQN2fQhwLs0Mw9o7SZQSttFNEZ/RIijs4+AvYccVoiWqNVpUl RWzWQh0/Pnbz26L3OPEiIzr/3j0Rf+8tpdfmXS4SElssTdbZs2VS3fmpkPFo3Qb1t2wc70JFNt AAAAA== To: Miguel Ojeda , Alex Gaynor , Wedson Almeida Filho , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Martin Rodriguez Reboredo , Mathys-Gasnier X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=ed25519-sha256; t=1707747202; l=1549; i=mathys35.gasnier@gmail.com; s=20240118; h=from:subject:message-id; bh=4WHIEGc6TIVbfvh7PeNOQmNjpDZmYDavVMoHaIlodHI=; b=q7QD3UdUQRQXztcJOdSgVPNrRpVwVF4EV+NxuHzQ0fNNhCQfFLrtc7vL1HeBf97d+i2Pm7BTo b6bOFj/3Ch8DHtpCfnUFM/cB2BPCMOXl2I+OUl/daVwpCYgt/NeZfrO X-Developer-Key: i=mathys35.gasnier@gmail.com; a=ed25519; pk=C5tqKAA3Ua7li5s3a+q2aDelT2j98/yjGg2nEVGArXE= X-Endpoint-Received: by B4 Relay for mathys35.gasnier@gmail.com/20240118 with auth_id=129 X-Original-From: Mathys-Gasnier Reply-To: From: Mathys-Gasnier Having a mutable reference guarantees that no other threads have access to the lock, so we can take advantage of that to grant callers access to the protected data without the the cost of acquiring and releasing the locks. Since the lifetime of the data is tied to the mutable reference, the borrow checker guarantees that the usage is safe. Reviewed-by: Martin Rodriguez Reboredo Signed-off-by: Mathys-Gasnier Reviewed-by: Wedson Almeida Filho --- Changes in v2: - Improved doc comment.=20 - Link to v1: https://lore.kernel.org/r/20240209-rust-locks-get-mut-v1-1-ce= 351fc3de47@gmail.com --- rust/kernel/sync/lock.rs | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs index f12a684bc957..d15af6625d01 100644 --- a/rust/kernel/sync/lock.rs +++ b/rust/kernel/sync/lock.rs @@ -121,6 +121,13 @@ pub fn lock(&self) -> Guard<'_, T, B> { // SAFETY: The lock was just acquired. unsafe { Guard::new(self, state) } } + + /// Gets the data contained in the lock + /// Having a mutable reference to the lock guarantees that no other th= reads have access to the lock. + /// Making it safe to get a mutable reference to the lock content. + pub fn get_mut(&mut self) -> &mut T { + self.data.get_mut() + } } =20 /// A lock guard. --- base-commit: 711cbfc717650532624ca9f56fbaf191bed56e67 change-id: 20240118-rust-locks-get-mut-c42072101d7a Best regards, --=20 Mathys-Gasnier