From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A479CD73606 for ; Sat, 30 Nov 2024 17:08:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F3E526B007B; Sat, 30 Nov 2024 12:08:43 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id F146F6B0082; Sat, 30 Nov 2024 12:08:43 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D406B6B0083; Sat, 30 Nov 2024 12:08:43 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id B69156B007B for ; Sat, 30 Nov 2024 12:08:43 -0500 (EST) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 5A64F40ACC for ; Sat, 30 Nov 2024 17:08:43 +0000 (UTC) X-FDA: 82843395516.16.BA5F7A5 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf19.hostedemail.com (Postfix) with ESMTP id 0249C1A0012 for ; Sat, 30 Nov 2024 17:08:28 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=h54W1a66; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=aQkjwsQZ; spf=pass (imf19.hostedemail.com: domain of chuck.lever@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=chuck.lever@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1732986513; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=jKGec9c3QUQHQ+SlyUMKAbWE7wCLQdchzjge/tYO07s=; b=6g+wsKeZJI+DiT0xagqyleIdQ+q0eAaSOEUHPoKx0PrEBf8tV09hEIIWzx2qeeEdYAkl3d iwWnaM4kmJMJu4JSzL2vr6wb38Iz1Q02QilI47imRUdl0DfQ+0Vtm7LKlXlfMAmp3Dg/ct Q8pEURN3TrNjeXKXzZIdb2OnygPl0ZM= ARC-Authentication-Results: i=2; imf19.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=h54W1a66; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=aQkjwsQZ; spf=pass (imf19.hostedemail.com: domain of chuck.lever@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=chuck.lever@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1732986513; a=rsa-sha256; cv=pass; b=wSsIIhJBUW0F5xTZdR7dDDabuP7sb8/iz90ZdbDlDk2pOoexnEcynfPjxLizUQWIQqzvZs ep5GIzo48ETehfiAkOyM8YG5mns+sPQhg9E4X4h7+LQilIrnGvl7QpgPjyWTsecZnde7+C Esbf3+jfgWM4Vb5Ds2r2EcBRZ3aD8f8= Received: from pps.filterd (m0246629.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4AUDwgIl015541; Sat, 30 Nov 2024 17:03:10 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=jKGec9c3QUQHQ+SlyUMKAbWE7wCLQdchzjge/tYO07s=; b= h54W1a66jzIpw1WolDZJJkrOyQPj1avmaaM0clnKJJe4wwWyYLvHnnijRMmLlzDS i4Q26C19EJSVo+XfG/qxyfZP5itJQw2oOAthjXAtZr7F9JALlyr5IQ3XDqIqumUs /hG5cDBbg7cR1w2cszbeHgW5p9zj5qVsDLzaJZ0/yYjrDsznQtyYZiu6l34U50cH AnPZrQogvZ7r/5kCpb0zgpzS+xc+IV3eOqV/URzTHAyUsYdyiFU5RoTaV380cSd2 g2ptjFL0zyUORb5GJTzQAlnZIdRYri6ODZReN19+QuGiQSn/YHOQ0+RzfV/79htg bjbgD3ixEwXMuu6LMNfBDQ== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 437tk8rkdu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 30 Nov 2024 17:03:09 +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 4AUCLMQB032899; Sat, 30 Nov 2024 17:03:09 GMT Received: from nam11-dm6-obe.outbound.protection.outlook.com (mail-dm6nam11lp2170.outbound.protection.outlook.com [104.47.57.170]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 437s55608r-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 30 Nov 2024 17:03:09 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=vZ3jUvXOo9x9jGjxpohRE8SWqXA6XiaplFYzG0GqHQoDQEvWANwyhPDGwGsQ5VrM8my1cpvPPHZf4vXXsM3eXU7lywKMpk7jeZlkYpSyCOqoL/GE1K3Z+V7bV+4anyLEMljNy/OM94/QPgep25IynClBbug8rgeL97/5l02W3XSUBCCkQS18TQyG8xPEHDzc0PlrwzsXs1Hbb+0Sv9mKs6RAhpk3krKET8EVLBBW1ce86yyE0DdEQzzvysK/Omjtn0lv7qV13OJ23EO92mgdytaZ6sgOD9Jq2ETfyYTB5pmqMeyRmyu0GNFqBfz88dXNcky0YxgJcuJmyojx86gK2g== 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=jKGec9c3QUQHQ+SlyUMKAbWE7wCLQdchzjge/tYO07s=; b=LIEvf2fjLhkKMaspbemI9Q8eGL0ncOH1b/VMYBuD0LzBXJa96LYHCJZ/J1M9mKDlV0BkY8wfUPzupq+Bg7WD3RtwZkdg6LNCUJt4oDfBn2WF5JxoVzQLwgyuiTIW5DkC9w5GRFuL+TFNAv5xE+Ujf5CVuRGPqqVTrlbtS4V5ZuB/OSSf+sj9p2uKST/yGJp6CdvlNTJsX1npUSK9IBxw5s345siWTkhfFEt5NqY1yJf5s26tzfx6UlDeaeCSwigXKgxPkIMKGIpDRqraxeua72zxBBcn213eFNnnTZ1d6JZ1q65C5D5P7ryvEazZs8NGGi/mFQ9Kf+0Tc3iIbflARQ== 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=jKGec9c3QUQHQ+SlyUMKAbWE7wCLQdchzjge/tYO07s=; b=aQkjwsQZL/mKBWLdE9TvQe7rJURARVmx470n50gEKiqCmPBSIrEIB49GFOijzyWeNQqLZwjTExae4lG8++Xcrj5EwzBr4TfrIKq2z7yoaXU2yr+ZIQtxA5aL22q0QYDTIB8LlOZ58LZGDhtgQ6aU6XME/c+84Uu3N1ReCBYAml0= Received: from BN0PR10MB5128.namprd10.prod.outlook.com (2603:10b6:408:117::24) by PH0PR10MB7007.namprd10.prod.outlook.com (2603:10b6:510:282::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8207.16; Sat, 30 Nov 2024 17:03:06 +0000 Received: from BN0PR10MB5128.namprd10.prod.outlook.com ([fe80::743a:3154:40da:cf90]) by BN0PR10MB5128.namprd10.prod.outlook.com ([fe80::743a:3154:40da:cf90%4]) with mapi id 15.20.8182.019; Sat, 30 Nov 2024 17:03:05 +0000 Date: Sat, 30 Nov 2024 12:03:02 -0500 From: Chuck Lever To: yangerkun Cc: cel@kernel.org, Hugh Dickens , Christian Brauner , Al Viro , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, yukuai3@huawei.com Subject: Re: [RFC PATCH v2 2/5] libfs: Check dentry before locking in simple_offset_empty() Message-ID: References: <20241126155444.2556-1-cel@kernel.org> <20241126155444.2556-3-cel@kernel.org> <6917283e-d688-a133-9193-ca5d6255dafb@huaweicloud.com> <234243c3-7368-4824-6c1a-ff9eee4e10ba@huaweicloud.com> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <234243c3-7368-4824-6c1a-ff9eee4e10ba@huaweicloud.com> X-ClientProxiedBy: CH5P223CA0004.NAMP223.PROD.OUTLOOK.COM (2603:10b6:610:1f3::24) To BN0PR10MB5128.namprd10.prod.outlook.com (2603:10b6:408:117::24) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BN0PR10MB5128:EE_|PH0PR10MB7007:EE_ X-MS-Office365-Filtering-Correlation-Id: e25537fd-7b33-49e2-50ce-08dd1160db85 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?bGNmV1R3cnVveTFQMUVJMkVaNUVGZkk1T2RPTzU5VW92RCs4SDQ2Y3U2WEFT?= =?utf-8?B?NjZKVExDeTBxejBXNUxsRUg1b2J2bjdWSStIOTJIUkVnKysvd0NsZXMyQ3JF?= =?utf-8?B?TUhwT3N4UTNDS3FGRlN3eWxvWElmOThhR1M1RzBFOWp2dDl1QXZzTkN3citB?= =?utf-8?B?c2thNXpGd1RXbnMzYnBCeXlOVEdOQS84YWI0dlBxYmpJNzJOVEdQNXRCY3Ru?= =?utf-8?B?MXZzVEp5MDljVm42V2hRYlNOQjErNjBGTUI4UFZPbnoxZTBQUHJpdFlSWTJv?= =?utf-8?B?aTBSNVYxNnlHa2w1VmtMbmZWeWxlc0oydlQvd0Z6dXF0VnN6a25ESFRrem01?= =?utf-8?B?OEpEUUxVVDM2S1lOVlU0c0VyY0Mya2FsWFVUV2dTZ1FUeG9nMm10YVZvc0la?= =?utf-8?B?RHB3S3ExZmRIRXNGTEZSK0Z4VjYycWF5enRkd0Zsa1c0ZDNRcllGeVVxaDVE?= =?utf-8?B?aXpDM3hOTWJjMmJHOG1PZXRiQUlpZ3JXMzNNdXp2K0YwMk5SaGgvSFVwQnR4?= =?utf-8?B?VDlJcmhCMFNhTDViTXpDeXJZYnY2OXRydy9BUUtLbmNRdXZBc05Lb3FsVVEx?= =?utf-8?B?KzVka2w1cVh1ZzlLRldoYXQ2eENmckxYUjhweXppdEpudHcvaUFNV2RISjY5?= =?utf-8?B?dEo4TFlzSHdOOUhDYllpNmtNU1hHamUzbnplSWxuQUJxRnFGNXcvaWxUbUtU?= =?utf-8?B?TVdoZHlXYVdkd1ZNUzMvVVcwWW1pQjFKUXc1MCtYSGx0Sy95ZzE1NmZSOTZt?= =?utf-8?B?RmdqS0FNUGNTY09vVDhUZ1owTzk2aklpVjN3anQ2SjZJQmM1OXlWRTNNTUJY?= =?utf-8?B?ZkRZWHJTUlR1VDZyM0JuaThuSHF0S0FNMmRHRTRMNzlIaTBPSXEwK2JvalhN?= =?utf-8?B?TTMzWUFMSXprVUpQWDh3eTJyRkhsb3N5YWRMYUR0cVZlNDNJa0pwaWpkYXVD?= =?utf-8?B?VG94ZDlxN3p5MzQyYTROVWU1YUt1eCtpclNvQ0d2YWlXeCswdSsrYnIwcWpE?= =?utf-8?B?M0JrdzRuZFM4Y2h0YTBLZEFrcXcvbTk0c29RQS91bCtVY0IxaXV0aW92OVhW?= =?utf-8?B?bkl1R3BGRTVjaFE2Y0ZUMmQyYndETXJHMmdnenViOEptSm1xNUQvNzg0MnMz?= =?utf-8?B?Q1V0VWhjM2d5SG5wWXhqK0ZaV1B1MjFZZElGMVUrU1BsMm9SMlU0RC9IYklw?= =?utf-8?B?YnNONXI0VStCTWlINkJrdXlTZDhQbno3Ly9qbUE0TGMrdmUycUtMdHpZamZH?= =?utf-8?B?NmlEMjN3UnBzbDQ0WDg2MDI5UXNGRFM4NXJ4Nk12b1UvYXNZY1NnUE5McHFm?= =?utf-8?B?T1ExYXd4NERpOE0zak1oZVZoZHJIOUZ0d2xuTjBESXNyUlBiaExvUkpUdjFq?= =?utf-8?B?bG1id1ZsZFA1UzNNWUZkd2xCZDBmczBPV1BzTmtsMEpYR3Zuc1lNdUZ3SGxX?= =?utf-8?B?QnNkN3N0cElyallJS2MzN3Fvb2t2VU9oeE9jOExuREZ0WkI0bFcyQWZKY285?= =?utf-8?B?SzlEYUdoaXFaamdPWDNwNU9RamxJbjl4TUMvQVdnOEY5K1N4dE5Qc3Bwcm56?= =?utf-8?B?OE1NeXJ0Qkh4dHp2NmxHQ3c3WlpPY2hpQk91c1dDYmNaeTYrYkg2OE9qc2hH?= =?utf-8?B?NHhlVUJIU3BQeXFnaWVnKzNrZmxia2doZ053ZytLSU9hbzVhZzQ4R0hEeVlG?= =?utf-8?B?b3VsZS9RSEIyclVJSSs5c2VvVm5SZFVJOXFwa1R0SWxvbHZENlhkQW95VU90?= =?utf-8?B?ZUYyQWprMUpBNitodUlHcmhiUitWT01WR0xZYXVMaU1LYUpLMlN6VDl5V3ZF?= =?utf-8?B?d3hvYW9icGEyYVdsRDJJUT09?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BN0PR10MB5128.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?SnRzQUFKZmxzNTg1dngxYkRFbkVUSm9sTVBBVDV0b3lkOGVLdzV4NjNsUHNF?= =?utf-8?B?MlZlUCtnazJEQ3NUNlJONk9kMEdPM0NLTHhDa25jU3NOWmtnZHlWYlZiWWY3?= =?utf-8?B?dndWZWg3K2srNGZ2UDVTTlU3aUp1Wi9RNmdYbFBvd2c5anJ3Q1plemtlQmdV?= =?utf-8?B?Y2VNemp1am5sMHlvdEhMaHgxUWJ5dFZHQU5CZWxwL1plbzhxbE1kOGlrazJt?= =?utf-8?B?TGNJY2swSy9ReFFaZm53WSs2MDlaSzhBcW16K2ZwRi80WUdoVzdnd1VDRzNH?= =?utf-8?B?WUtnbWh0bkJzMkJCNUl6MWNaQmFidWxQZVRrYllzZ1czQmJIOHdETTh4SXIr?= =?utf-8?B?T3JWQkZIZTBYV2JmQXZXSHNTUlQ0WTNkRGFtQzZRcTRld1o4VzB3VXhyNDRt?= =?utf-8?B?YTJ2ZFNwdE1TZ1lYK09NY21ZazNHWGNkU0hVclBiNFREUTZGY1puQlFMc0p1?= =?utf-8?B?UnY4YnQ5aFlEYjJQMFRFUkNrb1pqOU41dTNKMXd2RjJZU01qeTU2c044YmZX?= =?utf-8?B?YlYxVDVRM0xoamIrdXc0SnJ3SUxQa0JRU3phUHVickNOMW1ReU9nczBpWVZm?= =?utf-8?B?V3hCZHVoYjV0c0dpY1MzZUl2Rkdna2JaVnNXcklTcFdPam9lbG9ZQnF4TVJR?= =?utf-8?B?MFZOS3czT0NsdzFFOGhjV3h5MDg0c1d3TVhZZktSeE11bHpkQ2N1UkhzRW9p?= =?utf-8?B?eHhVL24rSTVvV1RKRHIrVHFJVmdXNjJ3TXRKZWFycEJSdkZrdmh1S3dheFNy?= =?utf-8?B?OVFoY0l0ZnZhWnRwWTRDRGRGV29pRERQT1htRGFiaEVEc0dSY0lNcUs1ek04?= =?utf-8?B?STdabEtHalhNTlA1RWJSUjVwOG5BOGc0cm1zZnN0dDlVSTRobFZFQmM1bjh4?= =?utf-8?B?UGJ1WU5kejBqbWZFSURBUkE2RzBINlpESTBTTVZJSXlodElzZHhUaTg2b1FT?= =?utf-8?B?SEkwaHVmeTZycUZsdCs0NTFUWTdsVUd2MnpxWjU0K3pOYUpKYlBnb0ljdzZn?= =?utf-8?B?K2NVQzRqSjNqb1Buem8wd2JyT1Q5TVY2K0FSYm1nU0RNVEVRaFRFQW96Y1FP?= =?utf-8?B?TmpHVUJJK3JGTHYzc1dkSHd4WGcxOWtVeXBNWTBGYmxONjZIODA4ZmhWL1pt?= =?utf-8?B?UzJQem1vR1JQayszTjgwSklrcGRBRWJEZERGRGNINnY3Z1lPbmx6SXlyMjVZ?= =?utf-8?B?eERRQng0Zm9NQzdhbm1jcGkybUlwMzg4RklidUc5VjVoVU9rNDRqaDRVZmIv?= =?utf-8?B?c1NEVVRxTUk1UGdKZFViRDE2ekpDbkZlNmtWNEU1eVk5OFJZa1R3SDA5WlZ4?= =?utf-8?B?RzVFTzB5K0dUeEk3WDJMaEV2TVV6bzJ5cWppNDRxSENsVk5pdnp5VFdjcS9i?= =?utf-8?B?Zm0rMlZWeWxYd3VFSmRqdFhFT1hrcEJjazdpZjJwYnFId0JrK0RUbGNBUzgx?= =?utf-8?B?ZmJhZGhFS2xoYmM1V3JyenhRVUtYRHQ3SVFvUDRGY2kyQWV2enphSmRwcDQx?= =?utf-8?B?SmJDNHJiMmN0RzM4cCtZRldSVEhBTGQwN08ydC9mYmlLRk14Rjl5TXZnNmh5?= =?utf-8?B?S3I3SWhwRnJISVp4Y1dZdnpFWjZ3bUlHcnRxNjBobG5ZeEhVUjY3MUFjd25T?= =?utf-8?B?ai9vUFN1a2RLU1JCSi9yTG13a095Qkd6dk1GQTZIdmxGZCt0ZUxrQVVSRnpB?= =?utf-8?B?QVRZSTJaeFVUNjRoQnlzMGxvZm84QVJNeWtuaHp2aEE0bHo2aGtKdEJTSGpq?= =?utf-8?B?aUhVYld5czhLblNZZ0tMb3ZUZ3FSM2F0NTl3RXNGUnU3dUUvb09hYUJqTW9R?= =?utf-8?B?dmgrNElweUNxWjJ3dlkzdDVHaWZPOWN2YnZRVFI3aGs1ZXlFYlhhR0dtam8v?= =?utf-8?B?NWo4eDhta2plQnBBRURPSVY3Tld2Y0w4OW5TcW1xQUMrdWdCSVJidDN3STBB?= =?utf-8?B?OG9teGJUamh3MUVYM2ZvV284Sm16NW1XSHpwaWdVQjM2bFNscXdWaW0rRjRT?= =?utf-8?B?NlZUQUtpN0Y2cnFaRm80UmIwbDFLTkFPV21GcUpyMUVrNEpxNERPNHU1L0Fw?= =?utf-8?B?TnEyWjJWR0pEd0wrQU5VQ3lWZ2ZocTVPa2pkQzgrRDFXOVk2ZmxlWnFCeXpk?= =?utf-8?Q?TpQnlFkFuOGKpUuJZO/U7p0vt?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: XOBrk4B9a+btQay+Yttg+nTTsEBcFiuLw4ULujcMhP459cNEGsHSzdUu6dwrBJEe8bV71HmWmc6h7ITubQBPMYSxb1uhB+apEVGwx0HXOvXirHerN48ew/QVrOsaUUY8t8brBrG/ftKUhG5SRAjxC1sZpMovPv0lEBeKOVXWga9RnMSVW6vS42RSa54CTfWPMubfST+P6LaBWIcsyIBAcq+E9cdUuK/GzGfbT6Kr1TVs7+MbTyYa01drOOsR10VatU33bNBA18zOZ+jEy4mCQzNkWzOEN5NmIlOkcfGJSX1zuqijsy21EQCwJqn45OTBttZNNeugRcB5Xp46lwiaj4ZPpEulJIGIJAB0GUZnTF5hV//axAHtOBRQ3OxLl0kBy2u0sYcTC5V4VOLZhYtvlCJva7wF27vUyk7ZsXcJQvrgUg/Ghuab2GXAgUy+zgipovP30X95IvvAWaebG7+XyaTuPUSyYJ8gNEjwUOfQYoDlThOk26AVdnKnNbRPwPXEXVh//cnFBw51f6nk9q4oDl+29m8NSIqexsVwFHamap8WSwuvF8daadnWfS+qeje724VUEdBae0qoLpgbSfGRYSRdRdZvTvcEdaNkAl3WvHs= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: e25537fd-7b33-49e2-50ce-08dd1160db85 X-MS-Exchange-CrossTenant-AuthSource: BN0PR10MB5128.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Nov 2024 17:03:05.6356 (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: mM6N79qT1QCz5R+thC6LmxAqefpvN+PwhYeU928xtESk3KEt9ICnPjjz5SpqS62jxenO4MHOqgjm8g5VcGFHyg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR10MB7007 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2024-11-30_13,2024-11-28_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxlogscore=627 spamscore=0 suspectscore=0 malwarescore=0 mlxscore=0 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2411120000 definitions=main-2411300142 X-Proofpoint-ORIG-GUID: kEDpPDW7lp3OtYyTexkyTBrZOWQHCKPE X-Proofpoint-GUID: kEDpPDW7lp3OtYyTexkyTBrZOWQHCKPE X-Rspamd-Server: rspam05 X-Stat-Signature: rz7okp35bb7ktjmi8oda5o5ro4jccsyp X-Rspamd-Queue-Id: 0249C1A0012 X-Rspam-User: X-HE-Tag: 1732986508-582060 X-HE-Meta: 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 dnECiePv 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Nov 29, 2024 at 04:17:56PM +0800, yangerkun wrote: > > > 在 2024/11/27 22:36, Chuck Lever 写道: > > On Wed, Nov 27, 2024 at 11:09:11AM +0800, yangerkun wrote: > > > Thank you very much for your efforts on this issue! > > > > > > 在 2024/11/26 23:54, cel@kernel.org 写道: > > > > From: Chuck Lever > > > > > > > > Defensive change: Don't try to lock a dentry unless it is positive. > > > > Trying to lock a negative entry will generate a refcount underflow. > > > > > > Which member trigger this underflow? > > > > dput() encounters a dentry refcount underflow because a negative > > dentry's refcount is already zero. > > OK, so you mean dentry->d_lockref here. > > But I cannot see why we can trigger this, if it is, it's actually a bug... > > Can you give a more detail why can trigger this? I think it is possible for the mtree lookup in simple_offset_empty() to return a pointer to a negative dentry, perhaps due to a race. There is nothing explicit that prevents a dentry from going negative while it is still stored in the mtree, although that condition would be quite brief. So, best to harden the "is dentry positive" check there so that it acts like other dentry locking code in fs/libfs.c. Perhaps labeling this patch as a "clean up" would be more clear. I will remove the "Fixes:" tag -- it does not fix a bug in the current code. -- Chuck Lever