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 C3B55E77173 for ; Fri, 6 Dec 2024 11:54:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4CED36B0257; Fri, 6 Dec 2024 06:54:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 47FB56B0258; Fri, 6 Dec 2024 06:54:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2D14D6B0259; Fri, 6 Dec 2024 06:54:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 0C0C16B0257 for ; Fri, 6 Dec 2024 06:54:18 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 78C52161B17 for ; Fri, 6 Dec 2024 11:54:17 +0000 (UTC) X-FDA: 82864375734.15.58377EF Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by imf19.hostedemail.com (Postfix) with ESMTP id 1856D1A0012 for ; Fri, 6 Dec 2024 11:53:55 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=Js+FCyJj; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=KpNCTdUi; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf19.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1733486038; a=rsa-sha256; cv=pass; b=8DzCdQGcL+UyP10tdgM14Cn3fAM2bJAxWWW/o4kahiJiKlWDwBdz+9yX1anc3EnpnFK+b3 V6Nd9pvhwMZ0AcgqZlZcEifsMqN8+iYCjIcjsl8wNI1yjSdbhuAGWuBhSM5zaXza0mdpDU 8rthqBvjT72Zdt5dp27nXrBnyOYinN8= ARC-Authentication-Results: i=2; imf19.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=Js+FCyJj; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=KpNCTdUi; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf19.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1733486038; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=bOSedgFw8G7QkjKBJsek9lJIel+CX4PG5n6tcbvvlnU=; b=iFxrvs8N3WXK1bXLS8YKmkLOTSpJNM6SwXcLmx518jtLz/sJT1zmzAlTH7Q9ib4HXTQnDZ 7Iy7RXgkSG5cWwztl3ysWz21YuLsCNovOaM4qZFFWacOJ3c3vg+HwPmcos7BiyrZ7D+Mov BRV8bxCUQVZ3N3SgVLCD0RcX5nu703I= Received: from pps.filterd (m0246630.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4B66s1E2024108; Fri, 6 Dec 2024 11:53:55 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=corp-2023-11-20; bh=bOSedgFw8G7QkjKBJs ek9lJIel+CX4PG5n6tcbvvlnU=; b=Js+FCyJjTHzl6X4Bbbq0jtSpkA7HuP90TZ vyclDhnDAf5TyD3iHsySd7PHIbj2o4ogx88aG0pQzTFvRMGBAiZ7oDvx/G+aVf+I hgGytomesFv5DgG4ir6KyURc+ZjvoX0LjC9HODjicxKK+elYn9EpPo7DJOD+01uU 0m5icNOypkn+xjZQGOniKK8l6TLnCzHu/BWCkgwTYRVAJTqPy6HY9lNbnvQbYnL8 rfcQprYsSUHAHgNIR4+5D9rQydMzohb63+/COhIi6qnL0iWUxvXRTp9a6JwYuPnB cahHPUPeb8LGOH3r57lNpFlqNbpnim3dp/VZEMo53oTSMYnXdN+g== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 437s4cd69q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 06 Dec 2024 11:53:54 +0000 (GMT) Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 4B6A19gL036915; Fri, 6 Dec 2024 11:53:54 GMT Received: from nam02-sn1-obe.outbound.protection.outlook.com (mail-sn1nam02lp2043.outbound.protection.outlook.com [104.47.57.43]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 437s5cr7ex-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 06 Dec 2024 11:53:53 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=sxKWFBZEwpeAWWS5aAr+CfP9HSuekRdDQX1hPJi8YGOtNfoCXOCudPkGXCnXefuvH/75RzNpY2BzXzW2NcCYdYOW1tWjyDcSOLfRNxe80+ecJnbNJ/9F0XmEpyE43A7nThS3wu+5O5Dv0PCqk4H3roJ1/FJ2HFuc6CZWW5U3Yp5DQ/HFAhSqUmnguJ94HJ4bNJuTQf+DTpNbwy7nj3kPLm1PTv32/T1ngwIp/Y8RHGNMumO9iDZY1DGfMkZArTa4OfPHU61RoqjjtymUMO4jF3V7ASct2MmfviqKLRXyu0KNQaX5TriaTreIxjNx1imBqTF3joOowFKWdj4xkdi9ew== 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=bOSedgFw8G7QkjKBJsek9lJIel+CX4PG5n6tcbvvlnU=; b=nF/Zit2sDqH0FC4hmcIO+HXGJJG+Jgimc9MrG87nwvB568/qhOBMedYzbqsFqrzZzLFNKmU2BuB+hwdPEMWs1jajTT4H9hh8LiFvrXv/f2LyVc2wuVC/x++nreyZvdMwtlfY4KlM147iqUAmWXO/lVvYx0suJjNz6V7kub2SiVcguD5vm9GyNwb412gIVsZl2KlpiFaTZRmPkbBP1NvZRDhed5sn/bDIGuM0mnZdDpBkLlaUOGWcXPkvVtvasFZzxENpMNPDoh8guAPv5FXWeVsH7XdJDae/+hjUeHA4DHUIN6tsj2zu5ZT0oCkIuyA/SzgX2W7i/IGxD9MB+xg4PQ== 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=bOSedgFw8G7QkjKBJsek9lJIel+CX4PG5n6tcbvvlnU=; b=KpNCTdUioacAkgQsWBxFd1vzSGtH9g5IofqUqE+2k76MH5BzRfT4ZbGNvyQ52YgoUFl5LD1g2ThL5f00TG+eykyBxJfRam2cka/0wrtgmJHXnqhtodOcBZNOdvdb0jP39pRGSkCm3QMOo6n585/s7W5e28PQsz+2e2oJtsOsUkk= Received: from BYAPR10MB3366.namprd10.prod.outlook.com (2603:10b6:a03:14f::25) by IA1PR10MB7358.namprd10.prod.outlook.com (2603:10b6:208:3fa::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8230.11; Fri, 6 Dec 2024 11:53:51 +0000 Received: from BYAPR10MB3366.namprd10.prod.outlook.com ([fe80::baf2:dff1:d471:1c9]) by BYAPR10MB3366.namprd10.prod.outlook.com ([fe80::baf2:dff1:d471:1c9%7]) with mapi id 15.20.8230.010; Fri, 6 Dec 2024 11:53:51 +0000 Date: Fri, 6 Dec 2024 11:53:47 +0000 From: Lorenzo Stoakes To: Kefeng Wang Cc: Jinjiang Tu , miklos@szeredi.hu, amir73il@gmail.com, akpm@linux-foundation.org, vbabka@suse.cz, jannh@google.com, linux-mm@kvack.org, linux-unionfs@vger.kernel.org, sunnanyong@huawei.com, yi.zhang@huawei.com, Matthew Wilcox Subject: Re: [PATCH -next] ovl: respect underlying filesystem's get_unmapped_area() Message-ID: References: <20241205143038.3260233-1-tujinjiang@huawei.com> <69b72e3d-b101-4641-9ce5-51346c93a98d@lucifer.local> <041dcc1a-0630-27b9-661b-8c64a3775426@huawei.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: LO4P123CA0132.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:193::11) To BYAPR10MB3366.namprd10.prod.outlook.com (2603:10b6:a03:14f::25) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BYAPR10MB3366:EE_|IA1PR10MB7358:EE_ X-MS-Office365-Filtering-Correlation-Id: 6b1fe651-71fd-4a3f-8f9a-08dd15eca657 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|7416014|376014|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?QLJ7nasKeHteIJfunN9ymoY5Fd8hXMzfC96+lG+og6MaNHkQasVmA3AdVP1Y?= =?us-ascii?Q?T660UnuqT9uddenr361mpa5j579G0l0sKPP/9UKE2lI+gDWO5Qa9Vf2851MP?= =?us-ascii?Q?yY5QquV/vFA2E5auJo2Rc/MMhwBUuA3ABgKRUYFSrOW4mw3H4t0ql+Fw1gDK?= =?us-ascii?Q?q8JRypQcK6M6Kcbnnez909TeU8SYrwapHb4Juyn1r2DY6ZgfvyJtysHHEW+I?= =?us-ascii?Q?Sv/THb1oTNJ69E+fahEsCL85ZHqDGF50gjvxPtzbtBXvodmPDd3H/tuKY8/e?= =?us-ascii?Q?jxq0ZS+YhXgWs62XRKI1186qtZKxBVJj4zhYobOuFzyiuw0DDtLw9gfYufLp?= =?us-ascii?Q?2XJLxv7T6PTQruIKpGddVVE7/56SV4JTGwPbygf0gyUetz0dpGh23Phgxtw/?= =?us-ascii?Q?n3T7i/XDlp48/x6BlZoMrd+icMG2fAArYYFM+Q/XiQ3T02iUxWJl/zllN53f?= =?us-ascii?Q?/TX2BTh891bmcR9Q8xoYZx7qPqP5CBEE0JXWP8w40JRouy8SgZLn9mHkiZrD?= =?us-ascii?Q?bLxtpDzJ+O0W8I8mNivurA8ztmiZqZyE36Fs9mMzE2iwKFxia8B5dKNlvcT7?= =?us-ascii?Q?Xjo8XholzSUJPnscRlKR3JI3fdUJFn22Gtt714zHjLFq26uvP9bbe5EPXbPd?= =?us-ascii?Q?YK15cxLKRTW3mfvh/Ww5/x5rSZEi/TBbYBtwthPvW7g++zATUeidwKykzdA3?= =?us-ascii?Q?DSxRmLB8r7LOspN4r18Mu6NDpsnC1jH0iinGR2AqOj1B+0fEBCNEeYHDfotc?= =?us-ascii?Q?GypaTrIEw0UBvneE3NF6Pcz4nRI1VffO1onk7Y10uag23apu/T2R3qlUlmh7?= =?us-ascii?Q?3KfJXVJbgA73+LPzo7fXbqtQwwNkw8OEdt1oA6PdbQt64vvUr9JGynEr3Qst?= =?us-ascii?Q?1Dd2JAsojfaMW3p/UN5llEdUKpPwShry78oYb0iCGQ3FzhDgkbOF2F/5Z+3/?= =?us-ascii?Q?574HFWCVebsQX7mYdwoW5NdWxbQZ3ELWalL8yeFVE5DQ4ZRZLMNvJc11Zs45?= =?us-ascii?Q?Kx6UhU+efEB55OJaQBy54dRblbQ2ZZEtlwWIEY1AqD/+xiNVkdyGmxPzwNqI?= =?us-ascii?Q?yaT8wzZisBFqFGxPZqLhPQcJEcasDdfSGlmITYOzvbjCVvZw3WLwQlSVFFQL?= =?us-ascii?Q?OQcwkWaIF2wGMp5UNx8i6e3cNOXJlB0f5hn54gE36vV/rsmp79PB6zr6gwL9?= =?us-ascii?Q?e/B5GHwW42w/OQefJCGW7250Sz7tDjgtIK+cE///MrvZ8aCm54+qKYCw84B4?= =?us-ascii?Q?h2wSs05JLpTef2n1GNPJWSpRZn5C3BVFDAeGrFFeB4T15uex5hL0SzAU3J5J?= =?us-ascii?Q?E9g2T98c/mnMSfO3LwOq3r9ekdvta1ggKqGyf8f+96TSlg=3D=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BYAPR10MB3366.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(7416014)(376014)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?oZiFBpGD+hyCNW5UDYVccdPJd8PQ0vWM+PPYVfNoNFqt64za1zk/64ex/yYa?= =?us-ascii?Q?E5RKnsQ8hdGonBvHd1THMhXllRR6F2wmPobmWvRRM5mnaHH6jPYwaryBrAMW?= =?us-ascii?Q?dTAsV/CLjGaK81Y26dAA5DJgK2hrLxtP8/IZ8hv0Qqvz2wjw4BMbtHaBweCH?= =?us-ascii?Q?qErG9hAHjf6msGQ1kF59VG+It0WB0tSB/Uu4EyQF54AsCKkMGL4QxmZtURy2?= =?us-ascii?Q?tmF+34gLEpJFjNKjnpW2k3X8wlnXV9IDZD3iFBZm865uuvB4/b+5RWLh1gPF?= =?us-ascii?Q?cA+IgYd1RZJcLfx153x3C8yFbZDhYVIl24Z2zioBa3+ARTH9GZh26yTZzL1j?= =?us-ascii?Q?Y2gdLmJ6lbCaiuGwwKYF9i/XGo20SYXQRaBaBj5Z5AqnoNBY7zMt9zhsKbCz?= =?us-ascii?Q?lr5kYsrzyQajMozfd5CIv9SJY+RcJe6djBf+O3vmcW20QfCW0FUhBzNbTw+1?= =?us-ascii?Q?56C3XYsla5Q0Vkj/8fAzBwFQE7HENM+Rb1wilHQjgKxXLoKpjnBrtFX2A5XV?= =?us-ascii?Q?w4We3J+HOW53K6BjHe8O+U8wOUmEDDU8dRoZqUFZp3qGT6MCQm3Hgmn9RNYd?= =?us-ascii?Q?xXAj2uk9NwpzZYFvsNaqF42TAt39KwrDg6N+129uWRml0H2Kxa2rQTemqDfY?= =?us-ascii?Q?oCx9OPrL7i9MgbS6SyaqQ/XmjTdINUPlLT9ASJ3gPxrVYjsLsIEvj+agpqY+?= =?us-ascii?Q?vtlUAvuWauJYyrLuC69K0en9jFiRZ5QWS2WLPGJj9hnIjybuQzeeS1t5Wsxt?= =?us-ascii?Q?qLknWzdv3DOaQy5hdu0hhQDdc1mfJk4MkjDoJijCcP5FZfi79/8F57fvxVnF?= =?us-ascii?Q?iebiCZCpRCMBDCwn00rWQeSdBiFmueizv7UbcyDXrUWmuGHntFK65G/ivfVo?= =?us-ascii?Q?YyIWzUa6qD0X6mjm8JUQ/Ssljs5XqG0mvSGRtSYVltIR1q3OokCBmIFH830n?= =?us-ascii?Q?iWELOLB60tLcb8n6ppDefTAxAsKbjAswE9dt00Dw49aHsxm02yMXTac9B9k9?= =?us-ascii?Q?KfJfajzGuJ7o6QZHkrqxfNd7Pe3yoqie3wXV3Yo9UguGXLG3ZIcxUWBORdVi?= =?us-ascii?Q?q8mb/H5ChB/Hspm2P4961MExRL/acXXRRN9W5hVhpn/m/dU4ChOoveQf0UfY?= =?us-ascii?Q?KXr4bG2zWiNoOeKhg4C4C8u27vrGQVlQ6QnLFeMp3fnb+eXOjCiSsYU0JQ1r?= =?us-ascii?Q?8MulVOOMqhPyAe8HHIzpF4WAMdzjHqQrFoqfDNAivdFOpnzl47jA2o8wcEgu?= =?us-ascii?Q?rfKlVKNyXlQbc2V7JaA5ot9X6mQsinkQGKwrvsTIacWVDDhiZSa83bKdIMIf?= =?us-ascii?Q?hUKgIOrFJ25fNbL6g0YonMT2MteV/1ALHuo1rIwvBMJxbkoN8t801gusdthO?= =?us-ascii?Q?v4xHSxp0zlJdh5wlB4AzmDywg179pW4pDKrgp7K/Ia1NCz5lPBpLfO8gbgaC?= =?us-ascii?Q?SJMNNCs1BAvnJZgVHIQ4BT+Db/XTggHnXKPwQAWDoUZjObm6XA6S3mNAYURJ?= =?us-ascii?Q?Xy48HPpoSQ9FTQLojkUgZUoR8iv6g9dvIVrqQh4SDw/OLKJLN4E+i06pdyLd?= =?us-ascii?Q?PTFlajrYn74gMZjwerXpu6Uv5yzLy7O/9wCelwr17fvMrUmTJeQa40TE1jy1?= =?us-ascii?Q?Vg=3D=3D?= 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: 6b1fe651-71fd-4a3f-8f9a-08dd15eca657 X-MS-Exchange-CrossTenant-AuthSource: BYAPR10MB3366.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Dec 2024 11:53:51.0106 (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: Jen0t/7sD53rRsqIKvtYJQlmNBXlT8UHZYD7Vg8xPjB6895n7/FfZbt5qT1Lotm8fYmaVI+mBqrpyV2wO+hssbXJatk6zkxv9FdfVsuxw4o= X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR10MB7358 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=2024-12-06_07,2024-12-05_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxscore=0 bulkscore=0 malwarescore=0 mlxlogscore=999 spamscore=0 adultscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2411120000 definitions=main-2412060088 X-Proofpoint-ORIG-GUID: ghnUS3G4IvLXr0JQDwuEFf1Z186FosTz X-Proofpoint-GUID: ghnUS3G4IvLXr0JQDwuEFf1Z186FosTz X-Stat-Signature: 4115171fuyirtqsk4rgwzjn5asnxxwku X-Rspam-User: X-Rspamd-Queue-Id: 1856D1A0012 X-Rspamd-Server: rspam08 X-HE-Tag: 1733486035-908439 X-HE-Meta: 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 B501KKMy 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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, Dec 06, 2024 at 06:45:11PM +0800, Kefeng Wang wrote: > So maybe use mm_get_unmapped_area() instead of __get_unmapped_area(), > something like below, > > +static unsigned long ovl_get_unmapped_area(struct file *file, > + unsigned long addr, unsigned long len, unsigned long pgoff, > + unsigned long flags) > +{ > + struct file *realfile; > + const struct cred *old_cred; > + > + realfile = ovl_real_file(file); > + if (IS_ERR(realfile)) > + return PTR_ERR(realfile); > + > + if (realfile->f_op->get_unmapped_area) { > + unsigned long ret; > + > + old_cred = ovl_override_creds(file_inode(file)->i_sb); > + ret = realfile->f_op->get_unmapped_area(realfile, addr, len, > + pgoff, flags); > + ovl_revert_creds(old_cred); Credentials stuff necessary now you're not having security_mmap_addr() called etc.? > + > + if (ret) > + return ret; Surely you'd unconditionally return in this case? I don't think there's any case where you'd want to fall through. > + } > + > + return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, > flags); > +} > > Correct me If I'm wrong. > > Thanks. > I mean this doesn't export anything we don't want exported so this is fine from that perspective :) And I guess in principle this is OK in that __get_unmapped_area() would be invoked on the overlay file, will do the required arch_mmap_check(), then will invoke your overlay handler. I did think of suggesting invoking the f_op directly, but it feels icky vs. just supporting large folios. But actually... hm I realise I overlooked the fact that underlying _files_ will always provide a large folio-aware handler. I'm guessing you can't use overlayfs somehow with a MAP_ANON | MAP_SHARED mapping or similar, thinking of: if (file) { ... } else if (flags & MAP_SHARED) { /* * mmap_region() will call shmem_zero_setup() to create a file, * so use shmem's get_unmapped_area in case it can be huge. */ get_area = shmem_get_unmapped_area; } But surely actually any case that works with overlayfs will have a file and so... yeah. Hm, I actually think this should work. Can you make sure to do some pretty thorough testing on this just to make sure you're not hitting on any weirdness?