From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) (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 A9EAC23875A; Wed, 12 Mar 2025 09:14:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.177.32 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741770842; cv=fail; b=Ab0mfqD1dG8rJP6oZjIvJR3dvC2cRRBn0H4Gdwjg0Q6aj27A/BAUGa0r9iG0jsTnwfjFCUQRYRykgVrcQEfz0jmm8x4bPWCNR5meEVG4erA2y9jEf4wizK+Q4G+J8msR24F4q8/bPfzvhfaUuIICceOGx+r3+cGAHl1BGqXPnoo= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741770842; c=relaxed/simple; bh=FCdD9cpoZEseeo2k0d+zNdC76yIKllHP2kdwKxC+zWo=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=nZCav6oQ4ENRffJIR2VJp9wq7XRqnkuBW9/j63tHfo+pxBnGQznR91pi82SSWhlyZJPJdQurBTIR03EnjBYYmAjE+42mxA+Q4iA+jLWmvrX3I/x9EbQf5V4abfpqAK5afvG0f1y2LZPxrTxFP3OiB3NHZ2SskLHZs2E4deSU6f0= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=DYdHptXb; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b=gbKKP6i2; arc=fail smtp.client-ip=205.220.177.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="DYdHptXb"; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b="gbKKP6i2" Received: from pps.filterd (m0246632.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 52C1fpPm022177; Wed, 12 Mar 2025 09:13:52 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s= corp-2023-11-20; bh=3Azrm9oKudfgHqS/HT6K1JWUDm49B2XmUygrFUxf5Ng=; b= DYdHptXbuR/Cd7ZNmfT7FoaOjCfEf8PqChxLH4Kh30bRKoE89sLotI/wCfKYTr3b 6NYPOWxl95drWSU0QEgpFxH2XpLbWyd0uE4CBIsx0Gm0cKH0JC/Qo7d2lICC8cqH iveW+hiYopaFclNe3XfY2g9CPe7um/KJp+YiroFZVxt9PPwjRI6akRIRmQ1t4ZmD lh7CXGb/EarvY1KtoIVPnz9zTYOEFYsaZ0Epu5UyGvwiNdP3t9e7owBNULcifT9I tf1/v66l563NrOe3c/tprwOsiboo5jjRMYI/uDd06MDPo8C0cz+isRr1+0E4/O2U 4MSxMvTKK/nL/0gmpA0DGA== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 45au4h185a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 12 Mar 2025 09:13:52 +0000 (GMT) Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 52C7HrjE003886; Wed, 12 Mar 2025 09:13:51 GMT Received: from nam10-mw2-obe.outbound.protection.outlook.com (mail-mw2nam10lp2047.outbound.protection.outlook.com [104.47.55.47]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 45atn0gjq5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 12 Mar 2025 09:13:51 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=iyQZZxVbl4undmulNpvEIaB/SkW11WFgdK+xuB7ZgR0mmEsM8I/fscaU7qCx+rAszuZZeZh5qu2sDBei/9J9Xf6xscykuT3gLHIFwHLcbqiv/Srr5I/QZC+4Ip/I3+a8iUPofMcyrmBdvG9E522YrqMhM7mQHcadSub+WlOJPQ3f+sVv9wz3ZXixJidsdgkkyF6QYp1TOBRJR0vIjxQicgSSObCtNZJQEKB4dv2rcVhXDx5Ummu1xRGrXoaBwfcRXt226/OknhI4MWTrBx+e6SuSk/5Immjywp9zr/rt8ha3sQj+NHd5WHZacUFQ0KxBXQVmoCcHo6vT+ARNmS48aQ== 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=3Azrm9oKudfgHqS/HT6K1JWUDm49B2XmUygrFUxf5Ng=; b=kNobFZmh5KK0lyyuo036dnV0EFU8PApyU/V1yWbRyIAoSzppkhUn1MTu/XUA0OD5zlwmHW5oVsErc7iAWyFYp9UNmFvs/nXFoLd6UXIKDoUTZMlkFDoJZHc8TQVYyMWWaZPJY6u1Q62J4PGZtOWaDwz6PsHp4EwMI47yRFooouBGIO2gr5ijPheAE/FROsv0etv5YAblKKT2qvy1Edq/Swb6Bg2CUTQwLiiPtTTn3wQK6ro8j8VFLWgzMEUVvhwyQ/FpRNTaqjIu8/1RmcNTnDGc7shQvl03sM9ZUc3njAjTusIw5eGtuUvxJYXxzVVIyLpO67uVuq5PPW+Knwyxcg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=3Azrm9oKudfgHqS/HT6K1JWUDm49B2XmUygrFUxf5Ng=; b=gbKKP6i2AhlrcYNMTcLRIWVx7MPAbRsOkTEt84uORogRDobHGYBe/FI/h9giNY5b/XP4kU4Ae4l557g2qn3VS8lNg88EsiUsyfIksFPtD+MtDurlHykjSTn3QYsoOm06wyStn41sRfE+/Cw6omg8KtrlRn9Dv4srtnEMQIdw2ww= Received: from DM6PR10MB4313.namprd10.prod.outlook.com (2603:10b6:5:212::20) by BY5PR10MB4370.namprd10.prod.outlook.com (2603:10b6:a03:20b::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8511.27; Wed, 12 Mar 2025 09:13:48 +0000 Received: from DM6PR10MB4313.namprd10.prod.outlook.com ([fe80::4f45:f4ab:121:e088]) by DM6PR10MB4313.namprd10.prod.outlook.com ([fe80::4f45:f4ab:121:e088%6]) with mapi id 15.20.8511.026; Wed, 12 Mar 2025 09:13:48 +0000 Message-ID: <81247acc-f0fe-4d10-a0cd-bbd5b792267f@oracle.com> Date: Wed, 12 Mar 2025 09:13:45 +0000 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 04/10] xfs: Reflink CoW-based atomic write support To: Christoph Hellwig Cc: brauner@kernel.org, djwong@kernel.org, cem@kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ojaswin@linux.ibm.com, ritesh.list@gmail.com, martin.petersen@oracle.com References: <20250310183946.932054-1-john.g.garry@oracle.com> <20250310183946.932054-5-john.g.garry@oracle.com> Content-Language: en-US From: John Garry Organization: Oracle Corporation In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: LO4P123CA0348.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:18d::11) To DM6PR10MB4313.namprd10.prod.outlook.com (2603:10b6:5:212::20) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM6PR10MB4313:EE_|BY5PR10MB4370:EE_ X-MS-Office365-Filtering-Correlation-Id: f72577dc-379c-4979-a01d-08dd61463296 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|376014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?OTZmRVRZY0NmeS8wSlFJaU0zM1hVaTdrUmdXSEhxUktRbUVoU21LNVdKU01y?= =?utf-8?B?dXgxZDVyRGZVWTFZZUFRKzl1aVFwdjg2KytuTVVucTE0cE1hMUdNVEVxZTFt?= =?utf-8?B?bDRQRWxlWTU0dlZ4MUdGazk5cXBuMTB3d2o2L3ZzRzVsWWlTS3cvbURnUi9M?= =?utf-8?B?MDE1TEdTOWYzV1hFZCtwVGpUY1BOb1BIdXlWVkFrZzhHZ0M3enBldmVDbXlV?= =?utf-8?B?MTBTcTNZNEdjZ1VENFF4QkJKaGxLclFxVmJUREhsTkF3TjRsdzN6QVdXMTVn?= =?utf-8?B?NS83Zkh4RVA2cmRnaEoyVm5LNXB0bmtTMkRTSGcrT05ESG1IRGVURG5NU2JV?= =?utf-8?B?a0JHU0N3MU5xMG8zU0ppdWpaNzRHTk14UnEzMkJ2RTlZWHZibzROdnM1RDVy?= =?utf-8?B?L2YvY2N0dFJISHRCR0o0M1h1ZExBM2lzQmlwc0VYaWdkZlpSdTZSOGorb0JY?= =?utf-8?B?Z1lraWF5Q280a1V2UE1xLzR3Zm5mcU1HQWtHemNBN0FmSmlWdFpSRWpLL3Qy?= =?utf-8?B?cGNxQnNaTHIzZzBINUN6VGc5b0UzTEZSTGU0TmRSMkhaOXpRZFB6eDFpN3By?= =?utf-8?B?eUtjRFV5MEdkU3paR0trVjEwWTJEUWVyRmg2SnFubmNYY0NKSU9HbHVYOHNI?= =?utf-8?B?ajZZMUZmcUN3R0tqUG1ycEw0bUs5bFJzcDhoSGF2ZEw2ME5zcFhIcllJNWQ3?= =?utf-8?B?MWVrS2txdDMyUnJXbTR3alpnbi93alR4T1ZhbmZZUEtEVm1mY2c2SEJqN0NM?= =?utf-8?B?d1V2STlSb2VQZm9CM3IwcDNyTWplNUt6a1VNSk13MXhCVGxXaTgwWGVDMlpS?= =?utf-8?B?SjNvZlEyNytidFJkWTRyemwzUzdINDBtS21UV3B2R2dWa0w0VUZqM3hRZXdR?= =?utf-8?B?K2Q4SjBQUi9mdEFiWTBaK29tUFB0WEl1U3VKRkpLU01aUUlETWFGSmtlZlFq?= =?utf-8?B?eHd2NjNnSjNTYUI1alFWNXA4b2RhS01aSWhlWWRadzVWcmZTS3BIY2FJWHV0?= =?utf-8?B?MzU0M05nVFp4VHFvTHlML051S1UxeC9GVWozL0RGZ050dFlmS0pteFVodU9Y?= =?utf-8?B?eEN0V2RISUtxeW9VM0FXclNuaUp4Tk5XbWdaQ3RZS3hWZ0tXeTZzQWliNWdR?= =?utf-8?B?bSt3eGJkTGRiZVlFL0pWSzBuYVVTMllKSnJsdTBaNHdzYy80NUNhcDlBWkZx?= =?utf-8?B?V2hJSndXN0lDVG45Mm51bjI3NUxvNEN6eHdKZmJEb0pibzNqNnpNaW55aW9B?= =?utf-8?B?Uld6bkswZ1hCaFh2WUxFeWRJWVVWRUdTQlExSjBsdUNkNUROQkZtQmMyZGRX?= =?utf-8?B?a3oyKzh5Y1NrZ3R5Z2JoN0tXcHlxQmRZdi9BZWtwYnlHeEVjMDhkL2ltZlRp?= =?utf-8?B?MFJkVHhxdmdUaGRZQ1B3cWRNRE5WeVhlWjZoTGo1UHNZY29vVkxzT1Bqb1cr?= =?utf-8?B?eWtHaXZJeVhjQjBCcmEzdGxva1B3SVlaQkJEd3ZQQzZNZ0xJU1NOS0hIM05B?= =?utf-8?B?WW40NHRpay85eVhZV1NqM1dzbUdVUFBlYlRPVVNnM204ZlM0Q3ZUWXhCRFJu?= =?utf-8?B?LytmUGw0ZFh5cmUrYks4amJIempSbW82WTByR2RmbWl2SDZjYVB5akhsRE1x?= =?utf-8?B?cGFscWZTM1Jsc0dFZW5QZ3VtWktFSFovU21hdk1NeUV0ejdhU2pjaWJxRWpC?= =?utf-8?B?YnFFSk91Y2FRL3hObml1azhYWHErcjdlQXJFRjNRbWJQR2hKSVk4VG1sUktx?= =?utf-8?B?VytsWFdoY09lUzN0NTA0UUhTZERFR2h1YUhrWUNpRXc2RzRCcEMwbmozUk1o?= =?utf-8?B?cWxLNkZjd2g1Q2huRU9oSXVFVTE1TytYV29oYi9VSDVhbkRmbnM4REljU01R?= =?utf-8?Q?LhjsXxbH4vulo?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM6PR10MB4313.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(366016)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?K0dZZWVodHBXbElHT1UxYnpISW1vS0FjUzdSOFRDQkZsSVBMV0g0TytFd1VL?= =?utf-8?B?a1RrNFQ1aE03bjdhTlpCdUYyaWUzUEc4aXdQdENsWENiSk8zaVhabUYraTdC?= =?utf-8?B?bTN1djVSZ2cyanY0SjAwMEY2SVhNUGFLRnQyUHhyMURIcFMwYk85SEMyUmpj?= =?utf-8?B?V3hQNjdHZjlpWW05TEN5d0JZb3hydThlYWRFcmsrUzJvNERQYjhiK3hzU095?= =?utf-8?B?ZGtNSldLNkxzb3JDZm1vMHFWa2dlNWwrZThlMFZpQitXMWRhMGx2c0w2UFJm?= =?utf-8?B?L0wzdWd4YW5DZUJ5c21BYkp4ZHkycElBUzlPK094WkVyTUwvVXU1L1ByOGJ1?= =?utf-8?B?VlNoalNZN21nTmlwU0dQNThHdEhWL1VSY0xSeDFpZFZpaCt3a0FTdlIxZ0Ir?= =?utf-8?B?eERJMXAzSm5XSUZveUgxN3paVkZ1MjRvZ1gyVjQvU1dEVUJxT3NDTzdsUHBK?= =?utf-8?B?Q3lSTHlOSEc4eW82M2tmU1RkY3NRU1FTRnM5NzNpMEtSSnh6L2dtUTRhZUJy?= =?utf-8?B?VVROcldvNSs5U3dzSzdoaVo3SjdYRlUxa3RCYlJtR0hZSThZaGFhVEJ1Sy9o?= =?utf-8?B?M0pQZ3drazlicmFnckFSbU5SQzYwNEd2TTZTdHFvU3czbWJtY25ONnVXQzli?= =?utf-8?B?aTFob3pPVGVDWDdQaUZJTnNaUUtCcUNtdHNWNTdQWngxZUt5aDZGa00wV3JW?= =?utf-8?B?MmpPYXFlbHlVVThDbjYxZlVncFIxdnpMTm95TUZsN0JudGttWmJrV2hMa3hi?= =?utf-8?B?dnVrSEk4U0ZQQTI5MlpFS3ZacXJWY3ZHMVdvUFBZeTREa1FEaUZRbm8xSm5i?= =?utf-8?B?V3FLZlRWZVJ5RWFwYlpLek9BdzA0ZGpEZWlyWnFKbTF1S3hweHlBMFdUSXJI?= =?utf-8?B?T21EQnBsMkNtSFRvSjFLek9qakpXTmhMRkg5cHV5azgrUGJzSkpqTkZFeVhm?= =?utf-8?B?YWxJaEhoRUR1U0J1cVpXSzhqdVFzTHpwRXFSTHFwWlRwS3F1eTBMYlFUQmV3?= =?utf-8?B?TnBreFdmRW1oVEk1VW5mTW5NdzB6enE4YVpxZU9mVndiUEdPL0xteVdWZUoz?= =?utf-8?B?M3g2M1NxdkV0L3BBem16T1lYbEhaN1l5NHBJU0UwSWc2L0VvTm4rRHN0Yzlu?= =?utf-8?B?TFR3RjhVbk1HWEpjNlh6WFB5ejU2OHRIVW1HZ05KRjVOVUxKa0tEalF5UGcy?= =?utf-8?B?YlJRUUlOTDFETFlacitNMWVJb0NVSEN3Q241VHZnQmptREord1lNczc3czdT?= =?utf-8?B?WFA1RlhEdmlvOSt3eFlJVXlPTzZTS3ZiczRmNlFUVFRPMzFFNDBsOU9tZWF1?= =?utf-8?B?dVFyWExJL1AxNC9hb3Jxd3dKTjRQdzFxcmM0dHJLTzNNNVFpSE1ldVVLRUEy?= =?utf-8?B?VXlNL0paVERnZ2NLYk8rRjQyZDNveUN6MVF6VmR1WU1sMjFPd2dJd3NpbU13?= =?utf-8?B?UmdySHowMER3dVJCN29Ka1l0MkNnczlDa0FxZjVpWnlxVVZQNmVBWXpSUjVB?= =?utf-8?B?bDF4bjdXM1ZWellJQlAvOHBLeEE3TmJSSVNtTGNLdUlsbjdacHN4UzRabUlI?= =?utf-8?B?VVZjWkJMcUlaajJiakZsM1hmMzd1eXpNKzc4dCt5RFpzelhPbGlIdjN4aXZ2?= =?utf-8?B?NmFtTHdIN1lXZ00xYXNWZVdtR2w1ZXV4SVZ4cjN0VnRuS0ZIWm9BYmFYeUw3?= =?utf-8?B?LzY1U1ZHZFA4OGdPTjQzWTdlUmd5UzNxNWMydlJBVVpXYTc5V0U4NGM2TXJI?= =?utf-8?B?NUY0eFAvQnV5TCt4Nmo3a1NsSS80ZCtqTzJobWhsZFp0ME5jMXRuOWRlQm9D?= =?utf-8?B?aGUzZ0NUeWFleXk5aksrTlhrU09KdGkrbFQxRm1aTEdScTQxd2tQbUZqSXVM?= =?utf-8?B?N1h6a3ZGajVVaW9XRjdHTFNsa1FpZ3pBUWhZR05SZHA1SFF3c0E2VDZacC95?= =?utf-8?B?VEJLV1FrOWw2anJad01UZlpnSTF3NDM4eklNc1Azc3dLa0RwaTJFTy9JUy9t?= =?utf-8?B?aEJaTFY0MEI5eEIwTXQvUjM5eW1PaTQxZmxIa0hSeUJwYnNJZ3I0ckY5cS9k?= =?utf-8?B?czBONW16N1E0NUpINlVwcHdzSmJZOGVzK1dXQldFMFhZR3I1eGYxTnhEb3kv?= =?utf-8?B?TThXc2xPT0VpOS9aZDdDNjRieVRXSDVsYWFtcFoyOVFETlF1dVE1Qjh3T1cv?= =?utf-8?B?V2c9PQ==?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: f72577dc-379c-4979-a01d-08dd61463296 X-MS-Exchange-CrossTenant-AuthSource: DM6PR10MB4313.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Mar 2025 09:13:48.3082 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 4KpaX1lvqoy1QT4r5EoZGkZ6L3Tnd3lTZPsaaSQJvMz1VrGoOGkEk1IxQEWqdxf2RB5QpUA+h7k3e7kHjI98bw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY5PR10MB4370 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1093,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-03-12_03,2025-03-11_02,2024-11-22_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=0 mlxlogscore=999 bulkscore=0 malwarescore=0 adultscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2502280000 definitions=main-2503120062 X-Proofpoint-ORIG-GUID: cL_SqcGN4XI-Ea-ZuZew0oSflgn_gPOX X-Proofpoint-GUID: cL_SqcGN4XI-Ea-ZuZew0oSflgn_gPOX On 12/03/2025 07:27, Christoph Hellwig wrote: > On Mon, Mar 10, 2025 at 06:39:40PM +0000, John Garry wrote: >> Base SW-based atomic writes on CoW. >> >> For SW-based atomic write support, always allocate a cow hole in >> xfs_reflink_allocate_cow() to write the new data. > > What is a "COW hole"? I really mean a cow mapping. I can reword that. > >> The semantics is that if @atomic_sw is set, we will be passed a CoW fork >> extent mapping for no error returned. > > This commit log feels extremely sparse for a brand new feature with > data integrity impact. Can you expand on it a little? Sure, will do > >> + bool atomic_sw = flags & XFS_REFLINK_ATOMIC_SW; > > atomic_sw is not a very descriptive variable name. ack > >> >> resaligned = xfs_aligned_fsb_count(imap->br_startoff, >> imap->br_blockcount, xfs_get_cowextsz_hint(ip)); >> @@ -466,7 +467,7 @@ xfs_reflink_fill_cow_hole( >> *lockmode = XFS_ILOCK_EXCL; >> >> error = xfs_find_trim_cow_extent(ip, imap, cmap, shared, &found); >> - if (error || !*shared) >> + if (error || (!*shared && !atomic_sw)) > > And it's pnly used once. Basically is is used to force COW, right? Yes, we force it. Indeed, I think that is term you used a long time ago in your RFC for atomic file updates. But that flag is being used to set XFS_BMAPI_EXTSZALIGN, so feels like a bit of a disconnect as why we would set XFS_BMAPI_EXTSZALIGN for "forced cow". I would need to spell that out. > Maybe use that fact as it describes the semantics at this level > instead of the very high level intent? ok, fine > >> @@ -10,6 +10,7 @@ >> * Flags for xfs_reflink_allocate_cow() >> */ >> #define XFS_REFLINK_CONVERT (1u << 0) /* convert unwritten extents now */ >> +#define XFS_REFLINK_ATOMIC_SW (1u << 1) /* alloc for SW-based atomic write */ > > Please expand what this actually means at the xfs_reflink_allocate_cow. > Of if it is just a force flag as I suspect speel that out. And > move the comment up to avoid the overly long line as well as giving > you space to actually spell the semantics out. OK, I can do that, especially since XFS_REFLINK_CONVERT is going to be renamed. Thanks, John