From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.openvz.org (unknown [69.168.225.77]) by lore.virtuozzo.com (Postfix) with ESMTPS id E9B288017D for ; Fri, 9 Oct 2026 06:30:18 +0000 (UTC) Received: from mail.openvz.org (localhost [127.0.0.1]) by mail.openvz.org (8.14.4/8.14.4) with ESMTP id 6996SmGi003822; Fri, 9 Oct 2026 09:28:49 +0300 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.openvz.org 6996SmGi003822 Authentication-Results: mail.openvz.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=virtuozzo.com header.i=@virtuozzo.com header.b="yCISuzHu" Received: from mail-pj1-f69.google.com (mail-pj1-f69.google.com [209.85.216.69]) by mail.openvz.org (8.14.4/8.14.4) with ESMTP id 6996SjTg003818 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=FAIL) for ; Fri, 9 Oct 2026 09:28:46 +0300 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.openvz.org 6996SjTg003818 Received: by mail-pj1-f69.google.com with SMTP id 98e67ed59e1d1-3aaee1fc104so2705986a91.1 for ; Thu, 08 Oct 2026 23:28:46 -0700 (PDT) X-Gm-Message-State: AFq9FYK/tl6WfREVKC0m0XK/u6ahTRSBCxukzh/etCLED+sqfIcbHt6S eEM3U6xGLG3xaRQBEnsYDTaYwiBCNsziE0oKn6xgXnbeh0OD8LLNaG7SF/eQW6YAQkD6H7UEY1P Pg88jV6a5jUvzhSIMroDVnmG6hOPE2NByl9Je4U0fmzLvcDZEgCL56w== X-Gm-Gg: AYBFou0Gu2LPKERULmIUrAfUwqwv5FQCR1mdNrXw0Aht2WQ9pMzBVgfiXHBGQYCXjws aEZCW1uRKco0hsGotz0n+672BUvE/43ln1dOoWdrHlba0u7V9VhFm7tfeTc1rAwsAT+l29h13QZ uzynUDRUfUvNghzrEE1Nn8hSB38iAvhxA8+X82xOClYjjx/Hj4WFYxGoZtw8DQN53mXzDiY+4oo AVpgOA5t7g3sGKG97N3VFkdiINqw7zkwFJZCxX5hzm4prNeMg3X0YGBQ0NuqtpNjgMZqR/LDvr2 L/DpJc+39kxko1HaWLbGoKXxfU24YwjsGo9dj5t+Brdf4P+zhk7kKNrr7mcN2yBo4Z6mVcYkYHV iqDCHYCZ10XsBknJn9aGgYQy4frgntyfZNYWnRfqrgj7sKexY/5LBh0MPuPNrOq0hbeENrRUklU 8wmbULvblcZyVhe5iT80tH2aRZkaq9r7a/EP0= X-Received: by 2002:a17:90b:35cc:b0:3a5:147a:3b63 with SMTP id 98e67ed59e1d1-3ab3a33db36mr1053400a91.8.1791527324879; Thu, 08 Oct 2026 23:28:44 -0700 (PDT) X-Received: by 2002:a17:90b:35cc:b0:3a5:147a:3b63 with SMTP id 98e67ed59e1d1-3ab3a33db36mr1053393a91.8.1791527324204; Thu, 08 Oct 2026 23:28:44 -0700 (PDT) ARC-Seal: i=2; a=rsa-sha256; t=1791527324; cv=pass; d=google.com; s=arc-20260327; b=IT/3KA0h9UoKIs+moprcDkkANwG5EmjwQ9A74/+yjNmdFyTL57AdwdOuQD0PSF2Bki +JhhaTN+pALtnW9VcsvumDxeJScrsiyjm8lK3xqdwwAIeQrGt45PFVZOFYTd2GM/YAO/ kr3drDqGrxLmVuw0y5JFnWAXQ8TNUalZRd9IEg0Zoz/EtyDBfF0dAjYmmX3v88lNZOuw mngxqvTPsgIF1jFuuRjAj84sThIDd/rStVc28TMBS1neXElnSoQ96WhPaiQdj2jHeAAJ L9Uq9+3aSBy5723osLyCIjdpmLtv4MqzA6C2M83mU7DlDFVH/TqDLYWcK4cxP26k24D6 EB9g== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20260327; h=mime-version:content-transfer-encoding:in-reply-to:content-language :references:cc:to:from:subject:user-agent:date:message-id :dkim-signature; bh=EmiP+9YWUb96KYYygR+njz0Zx1vPIOyB4YYm/mrS/IM=; fh=tMEsLKuDQ09qqpmC2pLav8OyMwzw4kazC9GBASug5RM=; b=Go8NyUeMgWetxOPAMITAfJdyL79fcYlOSZnrFYjM3ogXj6fgIr68p8Lk5rLxGdNg9l 0wWeotuvtpmbrD8QrhO65G8wfkInQz07IrZ0g7RYg67M0AuuNxrWAeow0HptjZ1vcNmr +0VFXLiPwxD21Mn5kqm4o+0skODI6ZbyxsoLP5iwD4BqHr9XRVjibCn/WiownZUxu0Vq oYwolNoHAuF++oJBW0vBW91Ll0eLHWDbFAq/vfIWOtjDkkDsmNClT111Z1DDMXwj14RA XH963ly7LaVSkNyapFeuCgIxOk2t/Qh8TOrCkDcYiwXJiXNux5Oz3WOMKUSg9DGvEdAT DXIw==; dara=google.com ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@virtuozzo.com header.s=selector2 header.b=yCISuzHu; arc=pass (i=1 spf=pass spfdomain=virtuozzo.com dkim=pass dkdomain=virtuozzo.com dmarc=pass fromdomain=virtuozzo.com); spf=pass (google.com: domain of alexander.ivanov@virtuozzo.com designates 2a01:111:f403:c200::1 as permitted sender) smtp.mailfrom=alexander.ivanov@virtuozzo.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=virtuozzo.com Received: from DB3PR0202CU003.outbound.protection.outlook.com (mail-northeuropeazlp170100001.outbound.protection.outlook.com. [2a01:111:f403:c200::1]) by mx.google.com with ESMTPS id 41be03b00d2f7-cd3da0a6edfsi1868832a12.345.2026.10.08.23.28.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Oct 2026 23:28:44 -0700 (PDT) Received-SPF: pass (google.com: domain of alexander.ivanov@virtuozzo.com designates 2a01:111:f403:c200::1 as permitted sender) client-ip=2a01:111:f403:c200::1; Authentication-Results: mx.google.com; dkim=pass header.i=@virtuozzo.com header.s=selector2 header.b=yCISuzHu; arc=pass (i=1 spf=pass spfdomain=virtuozzo.com dkim=pass dkdomain=virtuozzo.com dmarc=pass fromdomain=virtuozzo.com); spf=pass (google.com: domain of alexander.ivanov@virtuozzo.com designates 2a01:111:f403:c200::1 as permitted sender) smtp.mailfrom=alexander.ivanov@virtuozzo.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=virtuozzo.com ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=yZEhJKWGn/RJeTu5nlf0h1QRvmq6hJmpryn+KTKlEqtyDxwP7YG7lAXPGWMJnk38DzV2WWT9AObLTrjbiNv/ZCahIYCA1bu5j+rEEdVwoLlihFgt7MXvDn65M7WPydKxMo/5tyknPRxFEVydnfli2cL4c5BW3Ipr8++EpWcwXJDT0KIw2Te+tpcVKRhzF6mmvnKEGyQWqKcOOg7s0vlCg5DHQ5SC1/RSWtQkFE1+pq1Dc10qu2GFlNiIQ1IKglmDiS8jG7LX/mbFyHUUo7qWnq/G1Vu9CyZEWyzqgKp4/ZL0OYo/yQZ8mlsUm9scq9iyGOJ/pHm5PkJG8f6rUTxXIw== 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=EmiP+9YWUb96KYYygR+njz0Zx1vPIOyB4YYm/mrS/IM=; b=skV7EUyU8NnhmeCS4dXaWTpm3WwxH4ocdi+qckrrToWS2K9b/HGIZJ6q6M6uVxaaQ6z4K2OZsoZ5Vp7QhO24VSNVzgiaBOo0JONN8sB1GR94dyetREjt46xqUxMrc5PNZAB0NaVkKX77CloJXCSGg4mALaO8u+FoxO0ctoA0pF6jclSgSR8RCIv4JAKFMVJyGxJrfyMO50Py11ngpvDZel009FfXBkjx2UnE41PAECGm8Z2MEc78+DqV20R9oi2EgPTjrcDI0SZ//smLa/0nhiuvwhejQg7n9tgg6TnpKvFMe+po/65qlueK9kuyZZfPH1ixbKC0esigkq0vYjJ+Ig== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=virtuozzo.com; dmarc=pass action=none header.from=virtuozzo.com; dkim=pass header.d=virtuozzo.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=virtuozzo.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=EmiP+9YWUb96KYYygR+njz0Zx1vPIOyB4YYm/mrS/IM=; b=yCISuzHurlSNLRXicXUN0x/l36NbRjTIFt6CiVNxw9Zu6ruQTkPpoHAbc1J1mLeuq0CDvkktPYDmb5UuFzQAKOam26Jfy+H9Y5agUuXpUv/pQP2pGioPxr+ivL8G9Izs9LSBmMwL9zCWor+vYCXI5RHWF/pBjHLiXzRV/bO+m89hD7Em5ekgrc5SXE4RtG7Tqz2u8GYRilVORQEOw1qCqBdZrFDEyPQas5sFTq8p/oGtSMp9rliJOfdMCLgDgUJ6AcH4T6ROBx7/1q5sNIOHbc9Jbs8P9kIdSswJPSig0chVfGncD1zKgU5uIlqwycfy7JNULsl9DxKgPDkFBSGUXA== Authentication-Results: mx.microsoft.com 1; dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=virtuozzo.com; Received: from VI0PR08MB10743.eurprd08.prod.outlook.com (2603:10a6:800:205::19) by AS8PR08MB9978.eurprd08.prod.outlook.com (2603:10a6:20b:631::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.522.5; Fri, 9 Oct 2026 06:28:38 +0000 Received: from VI0PR08MB10743.eurprd08.prod.outlook.com ([fe80::7a7c:d078:f125:f16a]) by VI0PR08MB10743.eurprd08.prod.outlook.com ([fe80::7a7c:d078:f125:f16a%6]) with mapi id 15.21.0522.002; Fri, 9 Oct 2026 06:28:38 +0000 Message-ID: <488eeba3-6952-4741-bb54-8a46695d8894@virtuozzo.com> Date: Fri, 9 Oct 2026 08:28:37 +0200 User-Agent: Mozilla Thunderbird From: Alexander Ivanov To: den@openvz.org References: <20261008140333.614909-1-alexander.ivanov@virtuozzo.com> <20261008140333.614909-3-alexander.ivanov@virtuozzo.com> Content-Language: en-US In-Reply-To: <20261008140333.614909-3-alexander.ivanov@virtuozzo.com> X-ClientProxiedBy: FR0P281CA0193.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:ab::19) To VI0PR08MB10743.eurprd08.prod.outlook.com (2603:10a6:800:205::19) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: VI0PR08MB10743:EE_|AS8PR08MB9978:EE_ X-MS-Office365-Filtering-Correlation-Id: ed2aff82-64b3-493a-a380-08df25ce8db3 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; ARA:13230040|366016|23010399003|1800799024|376014|56012099006|4143699003|10067099003|22082099003|18002099003|6133799003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:VI0PR08MB10743.eurprd08.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230040)(366016)(23010399003)(1800799024)(376014)(56012099006)(4143699003)(10067099003)(22082099003)(18002099003)(6133799003); DIR:OUT; SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?K3BmMHlPVzNHVVNWUmJxSHVmZnAwbTN4QTg3dlhyUlJPWmJLR1dRK3lmNlRJ?= =?utf-8?B?OFNXVVZ1aGF6RDBVVnlVeXhWV3Rka3hJSUZzWTA1V3pHQWJKR2NIVnZnZklo?= =?utf-8?B?YXpnVFF6SlJBajNGZEpiemw2S3NITWZmUmpveE9ib2JWSDhydVBpN0d5dVBV?= =?utf-8?B?eUNJUGxQRTVCVHBSaWZwSXpKZmpGbzJxYUZCOXkxWnRrVWNwdXNIQTY0dTRm?= =?utf-8?B?WTgrODh3Z1NRNFhrMzY2SGJ2RXl5bUNTdGlQdGlhL0RJQkJ0YVhSOHJDRHh5?= =?utf-8?B?T2JIaVNZVkNEN0VJMmpaSTQwS1lYS1lkREdqRzVUK3djbjBVUHQxTnNQZVho?= =?utf-8?B?eVlUM2JlMHdraVI5UlA4aEFkMFg1UDl5MEtZckhLbDIzR3JNc1RCZU9yQkpD?= =?utf-8?B?bCtleUZwZmI3QjBHYnd5eS9iTUN0Rkw0Mnk5Zk9HbjVxRzBuRk8rOXpoSGll?= =?utf-8?B?WEpMZXR6MzFXdWtaamQvNjMvWm40ZFZUWm5oZjZmNlU4bDJLV0poSnF0M25z?= =?utf-8?B?N0Y1aXJoajhPOFI3cGdnaGRvTEZzQnNJMGZWZGE0ZHQwZ0Y5aGtHNERMcnFk?= =?utf-8?B?TFlQQWlvVHhZcndnN2g5OGVaZXBlaVlpa0NSUElLenB6VXp1VmNsTEhLL05V?= =?utf-8?B?TWxJb2VkNmhnOXpUNFBIZ040ZjlUZ0xyT0VGbmxVN0txQng5eW43TjArOWdX?= =?utf-8?B?TUZGcC9DUlpyWFFwbEs0TWgzc1hvNjE3R3RlNnJuR1ZQWjFIaXM4dEV0Tlhr?= =?utf-8?B?b0EzNW9seEM1aVFsVEFQWmlMRWdVMXNOYTlBK2V0ZGdLQkd0M0RJeG9PcFZB?= =?utf-8?B?THdNTWJicTlwcWtmdnFkSUQxazhLNDEzdDZnMEQ4RU1CcmJxM2ZrSDJZQkY4?= =?utf-8?B?OExBOVlyMDZib1diYlhWS01MNkJaSnQ3RGJYeldxbnJhSEF4Nk4rZVJvdFpR?= =?utf-8?B?cnVYVG9wZkd4WE5QaW9PUk5wdnczN29sUms5MVVlQkxQa0E3Zjl4dm5YRDZP?= =?utf-8?B?eTBxNlZpM3YwNlNJZERyZGR0d29aTFNpaTBJekthbkRDNDlnbFVrMjhoL2l2?= =?utf-8?B?ZlR1MFJjREF0K1JzQ1BWbjNpSDZsemVvbEcyaTFZT2N4dkthVHJTaUlPYUJX?= =?utf-8?B?TDZhNkowSHYwSldtWkkyVFg1d1BrRlVzNTNBaXJrUVZrLy8xbVBhakVFTzcv?= =?utf-8?B?TkhmTXV6emRrZFBaZi9GeXZNanZjN2hCdkROY2txUkc5REtJd2EvQjdyeHJZ?= =?utf-8?B?d25uTDRYOTR0SWdWK2N1SHVCdEtHdVJVUXdZOG8yQ25FdmpuUTI4VDd6Um05?= =?utf-8?B?YUcrb0pwbFp2RHNZRUZMQjBJUFVYbEZ2TjlNOUl3aWRXSHVFNkJBa2JyTTRW?= =?utf-8?B?QUlDY3pRQW1heGpYSXNNdWY4aEpFc3BoRWViN3lIMm5qaXR2bjNIYlFwdXR0?= =?utf-8?B?eU01ZEhoelozallBbFpXUzV4aVRSTFEyTXg3S3g1MElKT1F2dDErSXo3dGZF?= =?utf-8?B?bDRCRXZtbHdIeFVNdjlEaEhqaFltL0U3bGtHYzVJVHo5MXpjZEhnc01nWVY4?= =?utf-8?B?T0RPL05tV1JZWEpWdTVYMkkvQUZud2JjZ2NWNVFhQjlMRUJnNm5uZFhFenZs?= =?utf-8?B?RVJ6Z0M5WUROWDdlUGdXK1l4bGgyYzdZV3pwK2dkSU1HNGQ3MmZpYnlCRzhm?= =?utf-8?B?UUJuWkdhOUtybE5LUjVQU3dYOWNsUVFQQUU5YVNrSk9JdEQweW5iU3ZxUmww?= =?utf-8?B?aysxa2tVZTJ2cit0MGlZNGNGRFZJNFYvTWlzNDE4VEtlMDNSTFpxRGhtTSti?= =?utf-8?B?L1lJa1YvV0t3YjkwbTlJZHJUTVhHMFR1Zm5tTmRyS1VmL3pia3F4M2JURndj?= =?utf-8?B?NnZ1SWNZd0ZGR2M3c2ZGRldKeEJGWHRLZFMrWUQyS1dMam5QcElqS3ZwMGln?= =?utf-8?B?Q25UZlVyeEpRam9kSTV0dkM4bFpFQWIyZWJLMG5OZElkcWxuYVhieXpPSWk2?= =?utf-8?B?MjJsaXdnMkVaL2dyYVZrVTJXWmt6a0dNM21QeVJScGNJQ1VPOEJsRC96M09C?= =?utf-8?B?UXdxRDJoTlZJeUFjTThzMHFiME5EVVlKYUp1MXByMXlEYXVYajJvS0twMFE4?= =?utf-8?B?aldwVEZ6MkpOYkxhTG11VlF1YmVvaU1VNkhZYzBsbWFTNTI1dlFYRjJJZTFD?= =?utf-8?B?NlMrbXY0Vm9TcDlnWUsxNGoxVWphMUF5K0hlRVZSSm1MQS9qbzBnajFCblJo?= =?utf-8?B?d2lTUlMyb1FrY1FyOG4vb2lGc3gzd1hhcnVLdEV1QlJTdVcyYVJXcjV3NkJS?= =?utf-8?B?aVhPeUxWbzRpbEJtdW0ybmFyeVhBbElkRm12cTQ5NXpUZzA2aDZHSzFyTEVW?= =?utf-8?Q?ojSAP0MVutW1X3oc=3D?= X-OriginatorOrg: virtuozzo.com X-MS-Exchange-CrossTenant-Network-Message-Id: ed2aff82-64b3-493a-a380-08df25ce8db3 X-MS-Exchange-CrossTenant-AuthSource: VI0PR08MB10743.eurprd08.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Oct 2026 06:28:38.2580 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 0bc7f26d-0264-416e-a6fc-8352af79c58f X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: M/2cM8S2x68Ii6zFeX/SHcGws8m6OrV0kvm7TbZ50v7e8HYZs7IXu9TlQxW2BMSMmdJPwA0v2hnsHMTAmTL5mm4zU1u3vHGyXnlDM84TK5Q= X-MS-Exchange-Transport-CrossTenantHeadersStamped: AS8PR08MB9978 X-OZ-Fwd: true Cc: devel@openvz.org Subject: Re: [Devel] [PATCH hci-8.1 v3 2/5] dm-ploop: set delta is_raw before applying its mappings X-BeenThere: devel@openvz.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: OpenVZ development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: devel-bounces@openvz.org Errors-To: devel-bounces@openvz.org > [Severity: Low] > Can this unconditional if (nr_be) guard skip the top-level header copy? > The commit message only justifies the guard for an empty raw delta. > > In ploop_apply_delta_mappings(), the on-disk header is copied into md0 > only here: > > if (is_top_level && md->id == 0 && !is_raw) { > /* bat_entries before PLOOP_MAP_OFFSET is hdr */ > memcpy(bat_entries, d_bat_entries, > sizeof(struct ploop_pvd_header)); > } > > A non-raw top delta with m_Size == 0 appears to reach this path. > ploop_add_deltas_stack() calls ploop_check_top_delta() and then > ploop_add_delta(). ploop_check_top_delta() does not reject m_Size == 0, > and ploop_read_delta_metadata() can then return nr_be == 0. > > Before the patch, ploop->bat_entries held md page 0 in this case, so the > loop body ran once and the memcpy was executed. With the guard, the whole > function is skipped. > > ploop_check_top_delta() only allocates md pages through > ploop_prealloc_md_pages(). Those pages are filled with BAT_ENTRY_NONE and > do not get the header. > > Would md0 then keep the BAT_ENTRY_NONE fill instead of the header? > ploop_resize() reads hdr->m_SizeInSectors_v2 from md0, and writeback or > grow writes it back. > > This looks limited to crafted or corrupt images, since a device with > nr_bat_entries == 0 cannot serve normal I/O. > > Would it be better to apply the guard only for the raw case, or to still > copy the header for a non-raw top delta? The later ploop_read_delta() and > ploop_reload_metadata() changes in the series keep the same if (nr_be) > guard, so it does not look like this is fixed later. Fixed in a new commit: "dm-ploop: reject top delta with empty BAT". _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel