From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 18BEC3ADB94; Mon, 8 Jun 2026 08:25:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780907140; cv=none; b=gPSf2TSFitpMF9Q0XzIBvHhfFGq17sGLUnvpG6frn6QASA+Duj2sI47FDvctkN644jBixhYryUl3zrAkLbmIHmxC9akb652Nw2Q52ZktB/vgaqc8wcy3eMJeFUEc9PWSlrPg6niAEJF3wyvx+aMTBhOdxFrdDO2Ospo5rdrKe8U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780907140; c=relaxed/simple; bh=81tZ6uqr6vxiXYEcG14j37NbBeu1YXEHO1iGp3knNjQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=KpW0T/ZXlGrC+iwpfn/7e5l7u2XP8o2e5KjYYQ0w7QBKEzFXLVABy+pZnriM9vF+kmRMPPOA6cqitdWfjZFOpd6gZ3fAyMD6M+ApX4aI5SKdVhoGMnKRAxjJ5kBlFtHDqzCS1ntEsmwEEskSITfPWiLavdjohMYeqBVKNKdpomw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e2yWKUSj; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="e2yWKUSj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 782FA1F00899; Mon, 8 Jun 2026 08:25:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780907138; bh=UkXpD2yPDo3XPKG6ddQID2Op1OA1vFwtRr7+pDnM+FY=; h=From:Date:Subject:To:Cc; b=e2yWKUSjFyTfFH0G/TgVNH5bVnQSY0lHNiddneb0NKaWEaY6dwlXZzHm4mCk4AoSr rJbxPH+8SnALJdmln9S2ItLFkB5xF01OJZWaqsvhzHIJtb9FW4TXy8ZybwRig73NM+ SFVLfFS+vgqZEYsdCvhoZE6GNfjsjESuTYkop5WI0noTHIBTR6uoERHZHFdrl0NAau j/UdDg/DNuamHsVNyZ3bMfUSIDWdITssJlV2Nc+sHp9TkpSEX/QtWFZMckOMQEMP1q cPjKzs9w2emRqOI5O42jY/8jzm2mbhewMXhojgK5PyGwdON9bbx25Wfk6PxavpBFO+ wtw6YhsyI5m7A== From: Andreas Hindborg Date: Mon, 08 Jun 2026 10:24:34 +0200 Subject: [PATCH] rust: block: require `Sync` for `Operations::QueueData` Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260608-queue-data-sync-v1-1-0efff051aaf3@kernel.org> X-B4-Tracking: v=1; b=H4sIAEF8JmoC/yXMMQ6DMAxA0asgz7UUghQhroI6OMEFM4Q2JgiEu DtpO77h/xOUk7BCV52QeBOVJRbUjwrCRHFklKEYrLHOONPiJ3NmHGgl1CMGbI13jnxTWwpQqnf il+y/Y//8W7OfOazfDVzXDTeAM/tzAAAA X-Change-ID: 20260608-queue-data-sync-80b66ab312ac To: Boqun Feng , Miguel Ojeda , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Alice Ryhl , Trevor Gross , Danilo Krummrich , Jens Axboe , Daniel Almeida Cc: linux-block@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Andreas Hindborg X-Mailer: b4 0.16-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1827; i=a.hindborg@kernel.org; h=from:subject:message-id; bh=81tZ6uqr6vxiXYEcG14j37NbBeu1YXEHO1iGp3knNjQ=; b=owEBbQKS/ZANAwAKAfpQKQiqxb3QAcsmYgBqJnxEcvTUOxGfHAHKjSzJ5dLQqQJJ5urIlG2FA f1KxE4fUDKJAjMEAAEKAB0WIQRXitnI2WZ2JirAaob6UCkIqsW90AUCaiZ8RAAKCRD6UCkIqsW9 0FlPEACZZLNBWeKuWRs78Umrg5q2Wzmc/vTBJfDz6as9boc49kPDP83g7cJwTh96FZy1oY4hdaf 1R81MxGMUZs04JJEIyKUSdT1QOOM+C2okXgvQUakpij1R6Gvnfc1QuXpq2XuuzWoKqGvtrpwGrl 3Zpt3d96Pl1BreZ3fWROZKPXGaZFDwmPMqxN+gJ2eZX4+/AEoLpTHbUHzkWS+rsAOY07Dygbdww UgOe8Kd7zIznT68MvTGaKz8Spgd1CaLZPD0S00AN40MZjjJgH/W8VTeiIm4WvW92CmqyxzWcDa3 nWVUoJFjFE57rZ/T0Grqsw4YPqUJQvlw+kJM4P5eC4/ZbGzHOOlM0TtdE0zFBE/V4cpg64c3Y1i ytOWcnj9+fNoXdeAGkWWR6VUV2XhK8cG7RdrG8npo8QqznCr8QuPXeY/QBezZZkBnXYcFIiB7LN 8u8iW66QEADr0zeB1PJ67Nps6Vxb3yJXQ/0MeK1Q1gqnoeErojBKAFc1D5tOS5mFBxGqF5r7iE+ jJG/YMuO6E2whHhRNSZvm9CbA/fR4pRK9Pt0Vf/JAzyE4lw59NypQ+dNSbcKzjY8VzVkkru13n/ /25ysalabSp+nrtZ4QEORmXGOskPa1zTsZqq4T+/4wEapmnsWcSH1BOGZLdGgnEVhzodHUOc1qk /9LBnv/uzaAkm2w== X-Developer-Key: i=a.hindborg@kernel.org; a=openpgp; fpr=3108C10F46872E248D1FB221376EB100563EF7A7 The queue data installed in a `GenDisk` is stored in the request queue and handed back to the driver as a shared borrow through the `queue_rq` and `commit_rqs` callbacks. Both callbacks obtain that borrow via `ForeignOwnable::borrow` and may execute concurrently on several CPUs, since the block layer runs one hardware queue per CPU. That means a shared reference to the same queue data can be live on multiple threads at once, which is only sound when the referent is `Sync`. The initial `GenDisk` private data support omitted this bound, so a driver could install a non-`Sync` type as queue data and then access it concurrently from multiple CPUs without synchronization. Add a `Sync` bound to the `QueueData` associated type to rule that out. Fixes: 90d952fac8ac ("rust: block: add `GenDisk` private data support") Signed-off-by: Andreas Hindborg --- rust/kernel/block/mq/operations.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/rust/kernel/block/mq/operations.rs b/rust/kernel/block/mq/operations.rs index 8ad46129a52c..89029f468f44 100644 --- a/rust/kernel/block/mq/operations.rs +++ b/rust/kernel/block/mq/operations.rs @@ -30,7 +30,7 @@ pub trait Operations: Sized { /// Data associated with the `struct request_queue` that is allocated for /// the `GenDisk` associated with this `Operations` implementation. - type QueueData: ForeignOwnable; + type QueueData: ForeignOwnable + Sync; /// Called by the kernel to queue a request with the driver. If `is_last` is /// `false`, the driver is allowed to defer committing the request. --- base-commit: 7fd2df204f342fc17d1a0bfcd474b24232fb0f32 change-id: 20260608-queue-data-sync-80b66ab312ac Best regards, -- Andreas Hindborg