From patchwork Wed Jan 24 11:38:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Garry X-Patchwork-Id: 13528984 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (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 D3602481A8; Wed, 24 Jan 2024 11:39:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.165.32 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706096381; cv=fail; b=QqWOkD5KXS4eP7+GslE7/1gr/D8D8Gavs2oZlJbOkc4jZX+5tby8TvdELSyVtg7K3rJkLy+qQ1ENwDJsU4wg5PaWs8yPIdkp2OpIFb1PvYuGzoUT7Da6xhV3cgQvgUdJ8kP2ICmzivMihinW+wg7MXoGIL/s043qebuXNgyUl8Q= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706096381; c=relaxed/simple; bh=PMHDyZNfV2DC1qGD/isnS4zuBg5+k+pQEE0G8qmELok=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: Content-Type:MIME-Version; b=XOnNJz/MT6nHFOgp9v84ZMWNq1E+cYAMqAE57uHP9TNEHbuiNPytKSTAX3t8MtJrDWzaoQf+KfIiCLpo6vSln02D1jB/5VYQ67lzIE4DYB1r4zEeZMKNl61E1ifgRU+a9hpv+cIe20PR1sBnWDlnVFoRRokdV0xAjlzWYUn4rVs= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=none 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=bn+yrOO5; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b=Fv5TJYGL; arc=fail smtp.client-ip=205.220.165.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="bn+yrOO5"; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b="Fv5TJYGL" Received: from pps.filterd (m0246629.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 40OAxSLc019677; Wed, 24 Jan 2024 11:39:16 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : content-transfer-encoding : content-type : mime-version; s=corp-2023-11-20; bh=Y3ME8YWCmtMyUFFF+UFtbiXw6J8VGJXY+lK9KpwRI2g=; b=bn+yrOO5GtUoQo/iuyGJafKFXm8dqvtsEuLAUBI1pbslBZ7l33IZrHXgo4AMvC/eyXnH Hvs1ituE2wJtitbQNRdpl8m8eIfjhoIQjlCVeMCJVPxhkmsjmKA/59SJjfK9gL4lnKv7 ygwY7M2H8CZko2YFKup0V4A4pn6aT+2F+rV1i+P1NUoySHqr0WPIN0Dy40/GcmlwPPXn B3iw90CaK/HqORyW0TdOaXV9WwDfROmOlEun99SrZlbo/p3hcj01KOxzpKUBZ2OpH+4v ZpUDwFW3ByNHFPog+WD5nAOQ1GR/vBN1PmtAuFy/5I/Auo/y/uE71AOrh31+JqsV1n0A Xw== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3vr7ansx8b-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 24 Jan 2024 11:39:16 +0000 Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 40OBSk75006248; Wed, 24 Jan 2024 11:39:15 GMT Received: from nam12-dm6-obe.outbound.protection.outlook.com (mail-dm6nam12lp2169.outbound.protection.outlook.com [104.47.59.169]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 3vs32set4q-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 24 Jan 2024 11:39:15 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=kRbsPSP+8gLOp365nof8cX0ZgLhkC9yDiE364I2pS7XtJK6FzyKL7MXib9n67CeHGMjGjvfH1SuI5Mq4baF+yLMW6uqLLYUwb40dGBtGowMTIccuy/+935QgjGHzoHynMZupypbl0jpqW+28zgOUPnSSIhxUGU0cxo6kV2s8vwwioaRqYrEgwnshAN9PlqIRC8I57OzeDyjMLwUT3bzHWs2ZeMtlJ9aDAs/XKtbhJl3ndTFIsCsCkLUxtYPiHR+ABE5tNpNYV4K9JHPBvgfCM2MyXLZu1NeoyueR4TXMV0J6tvbxTEK55wp8rlULtJmt6INdLH0eExafUVpF6hzgjw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; 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=Y3ME8YWCmtMyUFFF+UFtbiXw6J8VGJXY+lK9KpwRI2g=; b=VYHB5y5E236SjY03srFwu8OImKi8unpG4ZLkcnX+g8JSdpz0vEJb4000P244BYs1Wx3l+vKEH3r8KPI0atS2XOEjU3xsp1NMg6BAenIZ0Bu04UdNBwPMzoc+DikgSRL99l307ZNS5lNlxqzIaMxYX+QVG3Wpa62462jFRVRcMGIY9covr6ZRUmhL2PdO63Uop031Si0tHUI09fR0ovMIHVw5Lqwn3MQrCS4CU8MPLztNt8bqA2FH/PDHUBi6IwTxezQod0CLTwJ/diwSMtFfyujE/P4Z8cg6boAY1WKe98cob333TUABy3g8liJ0jBm+p2cBNvTlAAiTKESoYgTMuw== 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=Y3ME8YWCmtMyUFFF+UFtbiXw6J8VGJXY+lK9KpwRI2g=; b=Fv5TJYGL+FN7k5u+j+Sy6e5UyGMgrT/mMO+oIWCvaN206uEmKclK2zp9zaHgroOrF6EYfeX+VejV4Cv5ru8OOyIOhwn3oN1k2IM5sknlaOnIQA2a8qvIMc9qXCQHD9x9jc92dbeX0YhdrAmfJeFRF6gbF0ry7ekgveodOOX5nc4= Received: from DM6PR10MB4313.namprd10.prod.outlook.com (2603:10b6:5:212::20) by SA3PR10MB7041.namprd10.prod.outlook.com (2603:10b6:806:320::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7228.22; Wed, 24 Jan 2024 11:39:12 +0000 Received: from DM6PR10MB4313.namprd10.prod.outlook.com ([fe80::f11:7303:66e7:286c]) by DM6PR10MB4313.namprd10.prod.outlook.com ([fe80::f11:7303:66e7:286c%5]) with mapi id 15.20.7228.022; Wed, 24 Jan 2024 11:39:12 +0000 From: John Garry To: axboe@kernel.dk, kbusch@kernel.org, hch@lst.de, sagi@grimberg.me, jejb@linux.ibm.com, martin.petersen@oracle.com, djwong@kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org, dchinner@redhat.com, jack@suse.cz Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, tytso@mit.edu, jbongio@google.com, linux-scsi@vger.kernel.org, ming.lei@redhat.com, ojaswin@linux.ibm.com, bvanassche@acm.org, Prasad Singamsetty , John Garry Subject: [PATCH v3 04/15] fs: Add RWF_ATOMIC and IOCB_ATOMIC flags for atomic write support Date: Wed, 24 Jan 2024 11:38:30 +0000 Message-Id: <20240124113841.31824-5-john.g.garry@oracle.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20240124113841.31824-1-john.g.garry@oracle.com> References: <20240124113841.31824-1-john.g.garry@oracle.com> X-ClientProxiedBy: BLAPR03CA0149.namprd03.prod.outlook.com (2603:10b6:208:32e::34) To DM6PR10MB4313.namprd10.prod.outlook.com (2603:10b6:5:212::20) Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM6PR10MB4313:EE_|SA3PR10MB7041:EE_ X-MS-Office365-Filtering-Correlation-Id: 113ee82d-97a8-47fe-95d3-08dc1cd1163f X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; 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:DM6PR10MB4313.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(346002)(376002)(136003)(39860400002)(366004)(396003)(230922051799003)(1800799012)(64100799003)(186009)(451199024)(4326008)(8676002)(8936002)(66946007)(66556008)(316002)(54906003)(66476007)(921011)(2906002)(103116003)(36756003)(5660300002)(41300700001)(86362001)(7416002)(38100700002)(6506007)(6512007)(6666004)(83380400001)(26005)(478600001)(6486002)(2616005)(107886003)(1076003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 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: 113ee82d-97a8-47fe-95d3-08dc1cd1163f X-MS-Exchange-CrossTenant-AuthSource: DM6PR10MB4313.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Jan 2024 11:39:12.8070 (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: QFZD4psspw8iEZQcmhZ9eEp8wBEizSzeJQFTsNedjIHOnRPOyX/KtACYv94NyhyGZfnnhFnM88rHIvR9k6jU9A== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA3PR10MB7041 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.1011,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2024-01-24_06,2024-01-24_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 mlxlogscore=999 spamscore=0 mlxscore=0 adultscore=0 bulkscore=0 phishscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311290000 definitions=main-2401240083 X-Proofpoint-GUID: EaT4RV5_cPT46i15wjFhBWg7xJngzrci X-Proofpoint-ORIG-GUID: EaT4RV5_cPT46i15wjFhBWg7xJngzrci From: Prasad Singamsetty Userspace may add flag RWF_ATOMIC to pwritev2() to indicate that the write is to be issued with torn write prevention, according to special alignment and length rules. Torn write prevention means that for a power or any other HW failure, all or none of the data will be committed to storage, but never a mix of old and new. For any syscall interface utilizing struct iocb, add IOCB_ATOMIC for iocb->ki_flags field to indicate the same. A call to statx will give the relevant atomic write info: - atomic_write_unit_min - atomic_write_unit_max Both values are a power-of-2. Applications can avail of atomic write feature by ensuring that the total length of a write is a power-of-2 in size and also sized between atomic_write_unit_min and atomic_write_unit_max, inclusive. Applications must ensure that the write is at a naturally-aligned offset in the file wrt the total write length. Add file mode flag FMODE_CAN_ATOMIC_WRITE, so files which do not have the flag set will have RWF_ATOMIC rejected and not just ignored. Signed-off-by: Prasad Singamsetty Signed-off-by: John Garry --- include/linux/fs.h | 9 +++++++++ include/uapi/linux/fs.h | 5 ++++- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index c316c0a92fff..95a7e2889d2c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -119,6 +119,10 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, #define FMODE_PWRITE ((__force fmode_t)0x10) /* File is opened for execution with sys_execve / sys_uselib */ #define FMODE_EXEC ((__force fmode_t)0x20) + +/* File supports atomic writes */ +#define FMODE_CAN_ATOMIC_WRITE ((__force fmode_t)0x40) + /* 32bit hashes as llseek() offset (for directories) */ #define FMODE_32BITHASH ((__force fmode_t)0x200) /* 64bit hashes as llseek() offset (for directories) */ @@ -328,6 +332,7 @@ enum rw_hint { #define IOCB_SYNC (__force int) RWF_SYNC #define IOCB_NOWAIT (__force int) RWF_NOWAIT #define IOCB_APPEND (__force int) RWF_APPEND +#define IOCB_ATOMIC (__force int) RWF_ATOMIC /* non-RWF related bits - start at 16 */ #define IOCB_EVENTFD (1 << 16) @@ -3344,6 +3349,10 @@ static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags) return -EOPNOTSUPP; kiocb_flags |= IOCB_NOIO; } + if (flags & RWF_ATOMIC) { + if (!(ki->ki_filp->f_mode & FMODE_CAN_ATOMIC_WRITE)) + return -EOPNOTSUPP; + } kiocb_flags |= (__force int) (flags & RWF_SUPPORTED); if (flags & RWF_SYNC) kiocb_flags |= IOCB_DSYNC; diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 48ad69f7722e..a0975ae81e64 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -301,9 +301,12 @@ typedef int __bitwise __kernel_rwf_t; /* per-IO O_APPEND */ #define RWF_APPEND ((__force __kernel_rwf_t)0x00000010) +/* Atomic Write */ +#define RWF_ATOMIC ((__force __kernel_rwf_t)0x00000040) + /* mask of flags supported by the kernel */ #define RWF_SUPPORTED (RWF_HIPRI | RWF_DSYNC | RWF_SYNC | RWF_NOWAIT |\ - RWF_APPEND) + RWF_APPEND | RWF_ATOMIC) /* Pagemap ioctl */ #define PAGEMAP_SCAN _IOWR('f', 16, struct pm_scan_arg)