From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM04-BN8-obe.outbound.protection.outlook.com (mail-bn8nam04on2052.outbound.protection.outlook.com [40.107.100.52]) (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 805E81A9F82; Sat, 23 Aug 2025 13:47:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.100.52 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755956869; cv=fail; b=XgPMIBXyEG+QORaugM/CepFjD+Lpz3IdW7uilyd5KUo2A+Si73nisWirEHdgum+PV4Cen+8dONP2DQ/rAcXs02D9KP7DqHLBWztrUtFo0wqReG8wkYdnYHyNWSvmTFuAKANA2CA8rHF/hTRlWc+RMt6+Y6MYWjexTajGaGVKCw4= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755956869; c=relaxed/simple; bh=3E43DWUqTV6PRCeDS4M0pPC0Ws7nqifGui159qQX+B8=; h=Content-Type:Date:Message-Id:Cc:Subject:From:To:References: In-Reply-To:MIME-Version; b=GhGCo/M+aExZixWdTtKI/vhpF8wHImse2E5U3IhzevSl/7jYennDS5BY2hUd4ZzV2YKmlCwWp3NZuuyuIvJn5O1OxZ3gHsQlF/lxe6eMpXa7AqNmGM2oGpDTkJYluPfEZmfufvo5m9XzTRvKTdDXe/zzvrFtqcG4yCuOsnkmFcs= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=VLopo18q; arc=fail smtp.client-ip=40.107.100.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="VLopo18q" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=LdsY+EYZqFdzinPq2hbfB19XKFSkiYq+z3bc68jc6Vj7Z0yBz2suWfvUQx73DSfPmY4MJfJt20FdQQK628sYp4JVJnyaL6VdxcPbSoy/SyFjuSIQZ/BTUXfKIoExCvgq/qiMjNDdrQMtmDa5EKN8prOtwZNqAZnhhP5gf5XUTq5b0MJdAzSnECC4riYtNSiDCAayAxRTSd17lvZkuQeJVYYTxGJvcxI9aN2O8SA4/Pq8FZB+GmcIcrYU9PIgW0evfogr8l1n1vBrvRGWByG/fQEzrHv3pFB8TpIMbHQ6vplyrjmQ+MNn6Lx5L7IXG+qufW3A0dl1WJArg+3Dyt/Z/A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=3E43DWUqTV6PRCeDS4M0pPC0Ws7nqifGui159qQX+B8=; b=NOB6P7dL0ChljRjxGYdbUeQMXHMMH8+9MOHQX3sHWjWac28aGzoiY9HQmqcq7PyVjwqwhz9eIkVjRe3jXUQ5te1ZlqhEkYq+cpWMgtBGEWRp7AQ6YzWIMN3UCh2Fap5sYPCAUKZNxwyEBAb8sq6h5bAVYtSWywTYBC4R7ckh4Wp4pi1vaF0en77LxBbbY9vGEJjj6DZhv6RA5zMfAFzU0MtbYC6pu8G5oaq+tyCs16hiJfJFR31kSL+WliHAjCFEGtyrRshvHX4Q+RGRosljF2xWshBFmjOaxgLVcu909HmaPpK9ZcavuDfuB7YKxPAom8ieeEXgrs3tNLz8muQUpQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=3E43DWUqTV6PRCeDS4M0pPC0Ws7nqifGui159qQX+B8=; b=VLopo18qYXXP4iYxlx5IYnKyq7A1dbNtgoY8zh/cvD3u6Ry7w4e6bXANmyg6vlHmFkOIkvtBXdQB0f06r8Rvp4uxRhKpz3Is/d9m6maya1GtSA0SKttzVcXdULhz7lVQybhZjiN7PpJAq4Ugc7BYLOxwpUMa9m1pcQ2iUAZmKFxpjLtVFrO56KoQrP6xFuYp7JnhIm+z/I0wyr5tXaQbfayweJh3v17xk4KLQ+j8c1BlKcnEQZ2OKD04ro8ywpX+YvM9+tmvg0KTnI8VyGDinhHsMCvA2Ymf7Ke7dr/gmHXRNm4uii4/mi9oRPzcYpFKGkr+Yu0gP2bA0qLQ0GPrgw== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from CH2PR12MB3990.namprd12.prod.outlook.com (2603:10b6:610:28::18) by SA3PR12MB7998.namprd12.prod.outlook.com (2603:10b6:806:320::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9052.14; Sat, 23 Aug 2025 13:47:41 +0000 Received: from CH2PR12MB3990.namprd12.prod.outlook.com ([fe80::6e37:569f:82ee:3f99]) by CH2PR12MB3990.namprd12.prod.outlook.com ([fe80::6e37:569f:82ee:3f99%3]) with mapi id 15.20.9052.014; Sat, 23 Aug 2025 13:47:40 +0000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Sat, 23 Aug 2025 22:47:37 +0900 Message-Id: Cc: , Subject: Re: [PATCH v2 3/5] rust: scatterlist: Add type-state abstraction for sg_table From: "Alexandre Courbot" To: "Danilo Krummrich" , , , , , , , , , , , , , , , X-Mailer: aerc 0.20.1-0-g2ecb8770224a-dirty References: <20250820165431.170195-1-dakr@kernel.org> <20250820165431.170195-4-dakr@kernel.org> In-Reply-To: <20250820165431.170195-4-dakr@kernel.org> X-ClientProxiedBy: TYAPR01CA0132.jpnprd01.prod.outlook.com (2603:1096:404:2d::24) To CH2PR12MB3990.namprd12.prod.outlook.com (2603:10b6:610:28::18) Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH2PR12MB3990:EE_|SA3PR12MB7998:EE_ X-MS-Office365-Filtering-Correlation-Id: 57b745ef-6b93-45fd-2bd4-08dde24ba0eb X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|10070799003|7416014|376014|921020; X-Microsoft-Antispam-Message-Info: =?utf-8?B?NitZbi9FNHBqTm00Y2VsZWhRRkJWejVINFMzZlNxajFOZHUvNTV4RHdyYlZT?= =?utf-8?B?cFVoUU1LRytxaGZRSTUxZFh6MzF4SUhPQUtHS0tlU3BGM0FEcjgvT0c0ek0z?= =?utf-8?B?bHZZVmt2czZCN2lMcVNLTWFxVHp0bW81V0pTeStiVmJIdkxPU0dYVkc3aWNE?= =?utf-8?B?aTV4eGFLTE53RGlHVDZUT3B1T3dKVk9PVDc3VlZ4Mnp6RkpZR2NVUkVueng4?= =?utf-8?B?ZDREblNWeXB4S2VmVXBBUUdrYzJ3U1Y1TUJCSTRkSFNIM21YVktFd1BMaU5Y?= =?utf-8?B?b3F2ajU4QVU1TGluaXE2Y211TmY1bVp4Z2tMYVJEMXFLbTBYTlUwZTFJN2F5?= =?utf-8?B?N1dYUnRjdEdhYXNFZndPanBWNkNVRlpTRk9lR1Z2cEV0QS8vOGQzN05idzh4?= =?utf-8?B?TFpzdFh0ekVtRlVlN2Ftc3FHeklPVjJ1VjBHSVB2bWVKQjhYYWVVeGF3Rity?= =?utf-8?B?ZHBkV1podjkxRVJDVFJPY0E3UmlYdEZPd2REOXBQR0pXK2ZEdDQzZE9XSGdT?= =?utf-8?B?TlJYSkgyelBVcG5DZnpXTi94ZlhnODZmaEVYbVp3VUhxVkN4ekFlR25oSStn?= =?utf-8?B?dC84S1JURmY5WkdVY0ViOXBaYVk3dHVwbHlnYkF2QUtybEtHMkhxUFhxUFBL?= =?utf-8?B?OGNDUHh2K0pnbzRrUTYrUkREa0loQXBnOG9aclhUM0szUnBIWVFoeW95ZHhQ?= =?utf-8?B?cVlXbENKSU1vVk5jdzM2aXIyVVNNaldpaGRKdFlHTEdjV2UwNHZxdUdiK0wy?= =?utf-8?B?aGxCanF1YllmWm95VE5sUDhlaDNqR2hyRlBXYytyY3N4WkovZnRMeXNGR1dW?= =?utf-8?B?Wkdtdk1NVXRYSDdEVWZuNWJKcUR6Nk1IMXNlNHhmd0NQV1FVUWFzWUgzRHlx?= =?utf-8?B?Y0I0bS9vTWt1cDMvV3FFckwrdnNZKzNEOWRDREtHd3hKSi81UWx3Z0pzeG16?= =?utf-8?B?M001bndTNEY5QmJ2ZWo4VW5QQVlxMXh5SnVralJNejBHaXZPRHErUDl5VTdq?= =?utf-8?B?NDFlNHRJLzNqWkpEaVNjcnMvQ0lOOE1xTTk0cUg1UFZIUi96RFdvVmk1SnNL?= =?utf-8?B?Z3NZUGxqdjcrSSs1RVArelF5Z1dKaDdIa1BzWUF3WkVFUlF1RU1oQ0NCZzlV?= =?utf-8?B?Slh3clNaNmpWVzRRbDVLb2FML1ZHQmIwODU0bXh1cEl5STRSNXRBeHQ1RGhQ?= =?utf-8?B?RkpFWk1RdCtra1JjRWNsdWFUaXdNSk1NYmh5cTZuYy9aUnM5TThDNER5MXFq?= =?utf-8?B?V3ByaGI4eFptWTJST2pLbm9pL1hwblNNM1o0QmsrY3R6blE0M0wvaVNDRWV4?= =?utf-8?B?MVRHTWtwbXFKbThzclJ5OVJoOXBsRjNReFFXK0EyVVBnQmswZVl1Ri9WeFFT?= =?utf-8?B?NFBzUGVxUXBRSHlLQ20zZlVydlNPd2E2V09iMFM5dlUxMGRDWnZkenJSVGYz?= =?utf-8?B?Zm04ZVVtSWtTZjVaKzhEQVEvZ1k1ejJnQjNpU3g0L3I2SEJRS1p2ckt1bU82?= =?utf-8?B?eHVkc3RLNW0rWTJpSUV1MWI3VjJETnJFMk9XRVhwdGZBZ3BlaDAySzBpYmdq?= =?utf-8?B?WXhlc1dQQ3NPZjN1STZlT1J6cFFTQUVMTVQxTXVVMUlpeFJyZ04xYmxwemNh?= =?utf-8?B?dE5kd0Z0aStJczBjbVF5OHR0YkxjaUhWVExpK203dTcxb2JBYi9qL3c1Y2dG?= =?utf-8?B?L3B2Wmp3d0I0RWZJNEdUdXFVc2pPVDlJSFNvdytLbDZlQU53VzFDM1Fod0xr?= =?utf-8?B?emxWVEdJYTFYQUdsZmV0NFdOSkNwMkxqV3l0N205NThDZjNSbm1LVWowSHAx?= =?utf-8?B?K3F3Y1BhdXZQZHJMRW9henU4K0JodGtrazB1dWNFN3BHYTNTRkdaN3JYb0Ji?= =?utf-8?B?aXlLUkhVUjhhL3NVQWxYa3NXUS9wZzBHZUcyU0svTGs0UjJDTnExTGlyd1Fw?= =?utf-8?B?R0U0Y1liTFJpS0UvczNIdHBuTkoycVZBNk9XQW1rR3RxelAzdm5IcjhTSFQ1?= =?utf-8?B?RjdSTFphWVJ3PT0=?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH2PR12MB3990.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(366016)(10070799003)(7416014)(376014)(921020);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?WmNDZHRaakJzNzhPNWxvMStERndYOG1mSkQ2Q28rRjhWa2l5RUZjNWVsNUJF?= =?utf-8?B?MWYrUnBtN3pxWk1QYzJLVmFJMk5palkrVndxMjdiZG9BNUdOT29xNUpic3lS?= =?utf-8?B?NVhwVG1XcWl5K0VFc1QrL0x4djhJZEpYVVRRMTRIZHROZXJvbjQ1T0VrS3hQ?= =?utf-8?B?ci9abXdBMDdYaDdGRVBNOEtXUC9BVUhZeW1WYWtKV2oxZ0E5OG9jRE5Lak9R?= =?utf-8?B?VDdUVXZwc2lCRktNWG1vakx0Nm90MlVJQU0yZW9tUndseENYbkJxVkhhUWo2?= =?utf-8?B?bzhjYjBFbWFqNVdxVzV0eUZtL21PVTc4dnphTWtRdmR1alJRNksyaDAzWHdv?= =?utf-8?B?NjNkV0hwZHQ2Y2ZHOVhGT2pWcVdxRjROVWRIYVM0eEpweVRNN1BhVU4zRit2?= =?utf-8?B?VzYzRHM4cU9DQkV0b0RvbjNScWgwd3pZQ2dHenVxaHZKT0ZHY2RBYlNlZndV?= =?utf-8?B?ZnFadXJqV3cxNXRzeXBvbmE4N0xmWnBHbVdENk5hNDdWVlQxK2dBdzBSRDBy?= =?utf-8?B?Y01CTkhTRjVyRm93cnoxTTlaMTNDeXVOdTBvOWhsZVdJVW42RWQ2b1NVc1Q1?= =?utf-8?B?UnNFTVZCcExMZG8rYUVmZHQ2VnRZcFEzSVVwQ0VkRm9VZXJBaEVqZ3pTcGkx?= =?utf-8?B?a3dZVHFxK3V5SkIvTWNjNFFCRnRFMVdyLytYWFNWRW1BOWZobUdzNlcrbXFP?= =?utf-8?B?T092eGlBdk93ZGVnZkJxTTNxeU1wMEROSnBMemRDQzU3SEpRVGZSaUorb0k5?= =?utf-8?B?SEZZZFdWSjVxRmk3WVNCRGNybWlYakRZbkpQV3RaRlRxd2M5RDlxdEJ4THNv?= =?utf-8?B?SksyUU5NWVM3eGZhL2NsSFBsMWRCejFyeExFQUs3c0JlblQ4Nm1CQll2QTM3?= =?utf-8?B?eFNkQ0ZvQUsrREpEK3Z0d1BIbzFGbTZwNFBxQnNmMmk5ajcwWkVQWGR5OWp2?= =?utf-8?B?T3IrUlhrcStrT0NtTXg0dlkxcUhEREh4TWwvNWw1eGEyR2NqZGo3MnpJYkNa?= =?utf-8?B?MklhbWZpa25LNUg5bVVwRHordVU2MTVJcUhmZExlbnhHREhlVFIwWDE2ZnJ1?= =?utf-8?B?U2NvWDNGVVpkVUhYdXJPdVdDZHpoVUxNSWltVHFpeTJER3RZaXFya1ByM3VO?= =?utf-8?B?YlR0ZmFRVm9uTG84ZlFuRmpSUHhsYzE2K09OWGMvUnhoTXdlRW1tckhwOFJW?= =?utf-8?B?S1V0R2xRaFdRSEJVaGRZOG51ZHVpdmUxNG1XV2FLNkJmOVRKY3dESzM2bWVr?= =?utf-8?B?cEx6MnNHMFA4bHFPMG04dWR6ZzMyeUJCU1pzdXljc1EwczZZSUx2Y080ZzQx?= =?utf-8?B?RkY5ajBCVVdGd0FFdnN0a0s2ZTBLZEg5YytwSmxOWTk4VjQ1YjZUZ0dKeEYv?= =?utf-8?B?QWZhK1dTcWRoNUFaVGxMWFlweXZUbDIvVVJIUXFnR0M1Q2I2RHEwZ3NmNytY?= =?utf-8?B?bytUYU1tays4YkVlNy96ZnFsa2JYWnJpdWVINWJLdnVRNi8wRmNrTDArV1pU?= =?utf-8?B?OXk3YUZmMTh0VmxhSFVSZnoxSXV1c3YrcDJucG1Ld25hNTJRci8xQ2Vxczdy?= =?utf-8?B?dHRZNzczNjY1Nm1DQm54NTNpVUQwaDRnRWxGbS9ocmRjSFFtY2FYVFpYNW9O?= =?utf-8?B?N05tSnF0UzRpbExUOE1RbDNNeDFNR3BUNTBJQUMrMys0OUovVGRRdUJ1VWlo?= =?utf-8?B?TDlQNEdRZ2R6MzhVelZ5WDBUZXVLSjU5alpiRkxKQW1OOU4rRXZEaUJlYlI0?= =?utf-8?B?Tm1qSnJMM3pRazdPVjBWekxDYkcvT292blBMakJQQ25nZ1lzRmoxVSt2UCs1?= =?utf-8?B?clBuN29tUytycllYUW1tZkxxZTFBNVdvRm9CR3M2eUh5c2RRUUtyQmZCeVRy?= =?utf-8?B?UnN2VHNPYmFSVitLUkFZTEpHTlZzNjlUZ2hSdUFQMGtpVStuRHh0ajNva0RB?= =?utf-8?B?MU03RG8zT0ZudHdWQkpZWjY1Q3lMdDUzVGNuazZLc0FKSUNCK2dlMWdtdDRY?= =?utf-8?B?ajE5ei9MbWhjVnZQbnMzamx4Q1JPS2R2ZEpFdDV2OXM3d0pGc2VOZlE1Z2s4?= =?utf-8?B?cU1BQ2dMY3BHU21Ib3RnSkpFNXNZbWpac1UvZWozQmJHd3Z0OHIrZTFuczVy?= =?utf-8?B?U2FDeDJRSjRGU2gzcGJKZFJ4ZWNLbjVJRkowMVJPM0EwM3dzTkZGVURJanJi?= =?utf-8?Q?L0YP+P263mbFiqW3VwJV5VVKviOSXHRZWlpsTOk3Iy8T?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 57b745ef-6b93-45fd-2bd4-08dde24ba0eb X-MS-Exchange-CrossTenant-AuthSource: CH2PR12MB3990.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Aug 2025 13:47:40.7950 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: jOHbntfF0YsUqsIXt2l0epWeMV9hOzDIREZa/Mtk874nXAvaOJGtpzF/x0TkYVXWeRUgC+Layrj4clB4a/5gpA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA3PR12MB7998 Oops, forgot to mention a couple more things: On Thu Aug 21, 2025 at 1:52 AM JST, Danilo Krummrich wrote: > Add a safe Rust abstraction for the kernel's scatter-gather list > facilities (`struct scatterlist` and `struct sg_table`). > > This commit introduces `SGTable`, a wrapper that uses a type-state > pattern to provide compile-time guarantees about ownership and lifetime. Is this actually a typestate? From my understanding, the typestate pattern implies transitions from one state to the other (such as Unmapped -> Mapped), but in this version there are no such transitions (the previous ones had, though). We are just using a generic parameter, so mentioning typestate sounds a bit misleading to me. Another random thought, in the owned case, do we want to provide an accessor to the provider of the backing pages? Or do we expect the caller to take dispositions to keep such a reference if they need to access the backing buffer post-mapping?