From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BD71A606A31E for ; Tue, 27 Oct 2026 02:35:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=Lhv5RFbX Received: by kanga.kvack.org (Postfix) id B14FB6B05B7; Mon, 26 Oct 2026 22:34:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AC6356B05B8; Mon, 26 Oct 2026 22:34:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 98E236B05B9; Mon, 26 Oct 2026 22:34:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 67F536B05B7 for ; Mon, 26 Oct 2026 22:34:59 -0400 (EDT) Received: from smtpin20.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id B19404091B for ; Tue, 27 Oct 2026 02:34:58 +0000 (UTC) X-FDA: 85366838676.20.7E7F79A Received: from SN4PR2101CU001.outbound.protection.outlook.com (mail-southcentralusazon11012001.outbound.protection.outlook.com [40.93.195.1]) by imf31.hostedemail.com (Postfix) with ESMTP id 8459720003 for ; Tue, 27 Oct 2026 02:34:56 +0000 (UTC) Authentication-Results: imf31.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=Lhv5RFbX; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf31.hostedemail.com: domain of ziy@nvidia.com designates 40.93.195.1 as permitted sender) smtp.mailfrom=ziy@nvidia.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793068496; 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=1cun7plN/2wHw0gxNzsc+UasoKl4vDi5uCYI5E5Jyes=; b=NfuR0OiPmhBp1cE4ElJeS/Nxla5BpkdRCYBoIl+Knx0p7aovS3mUcdhj1joUIzlifDQog8 dqRMHUBGJcCYY4OvqO1iXDtZPQMOqgGEH+8U7x6WAOTPpOCV06GF0lG6aQ1bQA/F13UtM8 gaO4BJ9V+jT4rJ1VC3pMLct+P0rdGOw= ARC-Authentication-Results: i=2; imf31.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=Lhv5RFbX; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf31.hostedemail.com: domain of ziy@nvidia.com designates 40.93.195.1 as permitted sender) smtp.mailfrom=ziy@nvidia.com ARC-Seal: i=2; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=pass; t=1793068496; b=fpDjVm8c7vVsmKTcVNuOVIcKTzmUHRDlrokrBGVTi6A8RxZ5mQiaG9i8LsQ0hNlTKNREJ2 v2LukTt4UjKbIHsjkyDzPME7qtOqV8K1zYAqLRMrDinDyIEAuTGrXKPY7/Lhm7VDKfZNCF 8T9JcWsGqyfsWY59wr2VDJmgnYBu64A= ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=wMQiR59mM5AyRyQ96QdTjZ3pMrYFr0hHQ0d4wEzLmlwSRQ4Z9jklGov02ICEycC+B/cL3bnPBCJkPyDIa4jmdw62xsza/58+8GRGDms/SXxKRCJ5KLopLRXVXiy3j/Vrv0kE+rah6EOhd4AVJtjjZMCYsqbx9aaGQvFaQqGqCvsqcmlKbyhhji/Agwy2c4lc0+S+12tk56xyAN9j54AcX9y53Za+plSfBnRAYGIbaoiU6AgVpzJmAYMGSUumCdRBgfAUzXQct7p1WFpCYBhaEkHPidNw0Z7CRY44ZB/fK5K7rF42NK4HK8ykz9Y+G7WvLbbThuT4jKKuON8jiWhDlw== 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=1cun7plN/2wHw0gxNzsc+UasoKl4vDi5uCYI5E5Jyes=; b=EN5qThuO4gE/cwtUjxFT/nUJUw2h+ovlc8+YW7PSGC82glgYorzxl1f+JxAl7hITG/QHKMrraO5f4mMW7BhmQyJn7ai/HeheVoHtzJl5fH6138EAsDIYroNF+K90JktFUo4tR5RRjqkm6GmAVEWjSqImHWnLt4ColouWWvXJj7CafTurtMRAT4Zv5e0jrmYfiWyO9gujar3r22wd4yMHw9Z8oNy84CbJhgWp+veXlBLOYioT/p/XoAbRlQH2r/pV/UQU+0Q7m+ITSod/M6x/ZEcOjOBZzCQI0jf9SHJ3JDr9BMaNxaLfkOeRaFWNLJ8x1P2n/jSy1mWgAueTJ8T5nw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=1cun7plN/2wHw0gxNzsc+UasoKl4vDi5uCYI5E5Jyes=; b=Lhv5RFbXq/tYKLyxQ2mkcazwlPC+9KoJRconXyROGsjyODWhiGmXTtbCPf13MrSNqdlnf9tsZcsP+QnpfaEfuwvrUvKsbzG0pe9S2FXCxHZtCEi1ondtZRMgsgNIoSotZ9KOM4PL+0p70byM5yINVuOYu4CRLVITMlAXlt+J3DAZFpabok5JUqu34/k2Lhg7FwEglUstNh/1tuptKsOyaCWKc9Gvanpih6WNZqJAmR0NOq0IStEm72FweUmsj2oToCg/fIMbaTeJ5vvGleHvj4HHQCVDSUQXEbp+BBFuW4HEWgabdNgSt1IMKQf2w0C9qrhQp6fPwJXnaQ9bGuNNzQ== Received: from IA0PR12MB8374.namprd12.prod.outlook.com (2603:10b6:208:40e::7) by LV3PR12MB9439.namprd12.prod.outlook.com (2603:10b6:408:20e::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.546.21; Tue, 27 Oct 2026 02:34:51 +0000 Received: from IA0PR12MB8374.namprd12.prod.outlook.com ([fe80::d85f:4c87:ae84:3f16]) by IA0PR12MB8374.namprd12.prod.outlook.com ([fe80::d85f:4c87:ae84:3f16%6]) with mapi id 15.21.0546.021; Tue, 27 Oct 2026 02:34:51 +0000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Mon, 26 Oct 2026 22:34:50 -0400 Message-Id: Subject: Re: [PATCH 11/16] mm/shmem: rescan after nonuniform folio splitting Cc: "Andrew Morton" , "Gregory Price" , "Joshua Hahn" , "Rakie Kim" , "Ying Huang" , "Johannes Weiner" , "Vladimir Davydov" , "Michal Hocko" , "Hugh Dickins" , "Baolin Wang" , "Lukas Czerner" , "Carlos Maiolino" , "Christian Brauner" , "Jan Kara" , "Daniel Verkamp" , "Jeff Xu" , "Muchun Song" , "Oscar Salvador" , "David Stevens" , "Matthew Wilcox (Oracle)" , "William Kucharski" , "Chris Li" , "Kairui Song" , "Nhat Pham" , "Miaohe Lin" , "Naoya Horiguchi" , , , To: "Kiryl Shutsemau" , "David Hildenbrand (Arm)" From: "Zi Yan" X-Mailer: aerc 0.22.0 References: <20261026-fixes_shmem-v1-0-703206d5fa0c@kernel.org> <20261026-fixes_shmem-v1-11-703206d5fa0c@kernel.org> In-Reply-To: X-ClientProxiedBy: BL1PR13CA0176.namprd13.prod.outlook.com (2603:10b6:208:2bd::31) To IA0PR12MB8374.namprd12.prod.outlook.com (2603:10b6:208:40e::7) X-Archived-By: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: IA0PR12MB8374:EE_|LV3PR12MB9439:EE_ X-MS-Office365-Filtering-Correlation-Id: a08dab7d-6b84-4a74-62ac-08df33d2e097 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|23010399003|376014|7416014|366016|261026121527099003|11063799006|4143699003|56012099006|261009223027099003|261021135927099003|261021121427099003|261022105027099003|10067099003|22082099003|18002099003|6133799003|261026140227099003; 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:IA0PR12MB8374.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(23010399003)(376014)(7416014)(366016)(261026121527099003)(11063799006)(4143699003)(56012099006)(261009223027099003)(261021135927099003)(261021121427099003)(261022105027099003)(10067099003)(22082099003)(18002099003)(6133799003)(261026140227099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?VFZWcGpXbGZva0xaeFUwZTZLUnVnMVJzVmhxNUs2aUY1VFU2cWN2cUs3OE9D?= =?utf-8?B?d2UweFBSNk14QU1XaC84SFZGTWlnL0N0RGhrQWJtTHc1SmFnSzNqUVVzSXFQ?= =?utf-8?B?dEpCZCtZL201R2V0ZzY4aU5sSzM0WC9kSno2WW5FK0g5UlJSZFNvd3BhdUh6?= =?utf-8?B?QVJxaUdlcDhycHM5T0U2Vmg5VnlIYjhMNTVQRUxtTXdrdzNyM2RzOHJxb00v?= =?utf-8?B?U3FVS3BrdU5OczRZd3ZUQWpBU1BkdWJOL2l2dngzVllRS2kwV3VOY29DWHlG?= =?utf-8?B?WTVwMUtXQ1Z1bDVheCtKaG1LNzdreGphMk50MGpuYnl6VUZ4cG1RNlRyTXZ5?= =?utf-8?B?NUxnMHFBWDVzYjlyVnhTZ1dGSGJkSnlNNnlMaUduV3BtUEtDUU9HTlhIVDdC?= =?utf-8?B?dW03d29MQWFKb0Y4cmdoSEpGT0JnTDZCUWV2YnhXbGlDZzRUSmxyMlRtRFRQ?= =?utf-8?B?OTlrNi8zTEVzbkRQZzZOVWtCc281NnV6TS9lM2JwWm1ab0l5amNBdmtwdHNM?= =?utf-8?B?MmlCRnhLVGNkYW45eHhiVzlGY2NrSlZ2elJDemVZU3ozcFNiRll1MG5wQm91?= =?utf-8?B?bDFFL2dKZzNNZ0NBQ0tjSVRMa2o0RTlSNmUxR2xteHpqZTdzbWVhaTg4NzRX?= =?utf-8?B?ajB6Mi90bkxkVzRoUWpqZlBzaWY3MnBJWkZJS0FRS0I0WTE5QjJUR1lDK2hB?= =?utf-8?B?SzBuakxYTDFHaTYvRjBDbUVMa0pBeUxCd2RPaEk0dWxRV2RHS2ZmWUNQWHNm?= =?utf-8?B?VjVQTjNWd0dsc0JwMnFsOURVZm5kVzVxWkR1YzkvdWN1YVArcldLVmpkdkpF?= =?utf-8?B?dGxRMnBPNlJSRUkvdEd2bVN2b3VtY0tkdWlIQmwwUHM3Q3VkL3hCeFJMem4x?= =?utf-8?B?Qnc0dXpSeE14a1h6VXpXbVBvNXppRUh1OG1NQjJXdmU1bzFnVGZ2aUFiOUxl?= =?utf-8?B?S1VNeXQxZW5GaUtBUTh5RVZnMUxwZU53NkZhejZKdXNkQmZmN2dDN2NFQits?= =?utf-8?B?anhxbGg0UmNUalZWYnhuTmFjdTJmRHd1Yk5lWktaQlRsY0wvdE4xZFo3Q0Q4?= =?utf-8?B?VEdqUUh5VHNWc1AzUDlMY1ZNZFhZQnpBbUw4TW1UQUY2TmV3M3lNMkhOajhG?= =?utf-8?B?QllVUm1QVXk0ODZXTXQ5a3daSG9wdEkrMHRhRWxla0lJZTlXMjhncHJkLzdv?= =?utf-8?B?dTZOckszbzNnK3RzNVRZb083c2g4RTA1dThhWjRvM3ArdDRaWHd4bm1Ham9a?= =?utf-8?B?dDVlUkozLzlVaU8wU2NHS1IrZEw0WXozTGt5b0puMzFreEd3OW1hNExRaURO?= =?utf-8?B?STlIbVYwS01TdE5BRjcra2NRVDYvQVFCem4vcFlOTk1va0dJQUtQSEI1cnF6?= =?utf-8?B?SG9VNU4veHBHQjQya2pQTUN1bXdEQW1OMDB3SHoycjZZcGo5S2FoVTA1OHdm?= =?utf-8?B?aDhKU21jV1R6djZubDZqRE5IWG9LbDgvUnhHbEowYkc0MFJ6S2g4U0d2bkJ4?= =?utf-8?B?UGdnT280Qk9hMVlQWnFwM1ZVeDJtZ0dpUWQzdnRQTHFvM3owcFE4ZFBmSjRn?= =?utf-8?B?RTFXT2loV2NmYlFCWjFoNHcwSDFCcFphMUNkb3JSQ2ZoVzZ0azdYUVAyU1dL?= =?utf-8?B?OTNYVm1oUUNyZnN3Sm9VdUQ3dFNDbFFURWdKT0JEbFJQb1ZWMEh5QWVpc1ZD?= =?utf-8?B?ZE1Ud05NVlJOc1FtcG1Gd3hieGVRb0MwVk91R0laVHRyQjlkMm5MUzJyeTdM?= =?utf-8?B?RWhWYzFIYVd6alY5dEdkcTRrVjZxMzVUYVZQQ1RGeVo2VkJRbGVEUjN6NW9v?= =?utf-8?B?VTNKWCtGZExSRHJXL0ZjQXV1eGR4U2UyZ2NDSGN5TVcyUDcxNmdmVmd0Z0M0?= =?utf-8?B?QVZPZExGdWhBK1ptNXVWd1FoRGtqeERpeUxrZnhaVmFHUjcwQ0M4MmI0SXY3?= =?utf-8?B?aDVQcDRvMVo1dkxDK3VLem1HY1NDQVMrN1lLRVpObjRnVGx3V0ZQUE9tMzZj?= =?utf-8?B?a3pKQk9STEFHZFMwT0todURMREFadDFIam9FMnlYb2JIVm91REhZdis0N0xO?= =?utf-8?B?bm53WFoxVFlBaVA4RWNJdzRKSlhpMEc3V1d1Z1BxMTNMZGN4Nk5zZko4STFG?= =?utf-8?B?WkJkM2orbStGYkRuT21SeVo2Zk5KQ0Y1OEdMM0FXSzhZVWt3K01JRlV6R0pq?= =?utf-8?B?S05tUUFHeTNjODNkTlpBWVRwUTJKMmpDNTdMWm1FUkFTNW45eVhUSnFwby9q?= =?utf-8?B?MUJMSFQ1dDNpM1BRTVh4NXd2UGxvenVuTVp4Y002Y2pUcyttQ1dCREN5cnRN?= =?utf-8?B?RXgvZ2RGY3hhVWd2NUNLQWVGdDdENnQ4Mlp5WHdyTDRray9vbmx1Zz09?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: a08dab7d-6b84-4a74-62ac-08df33d2e097 X-MS-Exchange-CrossTenant-AuthSource: IA0PR12MB8374.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Oct 2026 02:34:51.5355 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: eiKFNjln6T/gMfAnK/KucSkLSZBkgXtABKE8jp3KIKhV6mQNrfcZRrxhO97vK42y X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV3PR12MB9439 X-Rspamd-Queue-Id: 8459720003 X-Stat-Signature: 8bssam1obfmgeerpiosuuf5ucbg95848 X-Rspamd-Server: rspam04 X-Spam-Status: No, score=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Rspam-User: X-HE-Tag: 1793068496-309180 X-HE-Meta: U2FsdGVkX1/jywa0np5j+aNNmcCWQYfJeXpFgHNwHa/k3SEYxGP5gitGZZRRIPz5Rq4/BWaOQCFxVEvSKAtNQyYZ1B2qsfd1pwFSkCEVI1HzsnMaqPKrv/Dy1j4ykbBkIPLN3gmezRrg5/lEMK6s6PBKdQMZ6FJyBGC/qIPfCOP8qqfa2M6CQ3PdEzBHkYjMbKiYNh9h2PpOsXh62THDFO7IrKFrm4FKbf3rR/XOlV+F0Y+FdwhjYxjT68k/76rRs4JkNnPTP4gc8EjG6CCs48od1P+96IdQMOnvFtzF2qSgvAeSrtppKnsVZIJMPODkoA23X4Tl49ji0YfY+RNd3qvEe/DNSLWkbTqVuzswnqb1i4yq4xJZZ7SpwbWtWGIQKtNAfM8jGOQSte/sadIl8ySWSv6LXgIQR79MGHpLdBf7G/5+NwXKrw9HfUYKjFY1pluRO3VXnSYUF/Jc8pHouqxCIMMOFfaRvFyGij0bmGwF80Q5GqfxqP/s1Ijwj3Y5L2/ERJa6jVrGy93IocDv2N8XOBC72ElInwNG2iNuv5QLCzSfzPSrcGv0sfcMWmUcj1klbeoZ5so1BpGkeO2Pt8zKDVtjdXC3hDB21u5hCU3ePwb8NoihMVxNeb3J+ThAYzrUDJNgpdA7dbsuwWBK5qsbh2eme5Sa87EnOCO4bifF+GeUrByBeDldXTsV7k3TiyYbCWwMrvtt9gSyZ0T0lNrHZYKpLrv9zS8Ya4yzZKlFvYrM+yFw7RqZW7q6D0CKRwHdt7XEYULk6xSeBlEPytswn6ag3HBQ1mm33G0lJUflJsaWZVdF3z5ycpia3Z2lpKqVMmDmVQUy6mHgeGDriVomZ5yUyj2rZAvj/pjq/dFawA51B9BABdKYgHh8NtgbYpuhu/93spMC2vzZOVN9lU3INETJWXf+txzMlNcVepPqn0wUEWp3rsb6kraTba3tPIAEH3h3004kcwvLS5N ZLENBt7x HWlWpyq9BZOsC6Gp+pAGKgbw/r5DB/nk1JVT67RF0uNXTHzwlGNiz0OZEBXp8ts+Zhk2VtJZhYmFoZTEFMBjQwq2m1FlPAqmuD69gYWJ7lLAhbNR+G4tKrkMScg4k9PnYPLPARIBnh8ad1OqYfa/pZDlyJUC2ZN9WFzK97q3H7t4TY7BzoV7rUagBHy7MxjFKvlPa0Aw1LW9mLeQ9lMR58OxBrP2ACrh2ffEammN7nI7PIxWh5kaTm0bW1cdDCFGZ54AVvd81CVcjF+c4FZ5/wJjIlWY8xrjyNOxV4kH1s3mfVNh4/OZrW9z1iDxkghuUTi+73x1/ykjdWhq3+aOc9GNbtai2P+mhGQgjxRv1Gpu3dmlNM17vbQ9QWTLwVVuEy7O8XDKNLu3AQ+68o2itqJRTyULAcWOGmNur+ZISocEhjx6jk6w1OPzlTT/ZE8f4nfc8imtLWOS3zSE+mUhdr+FwoJsxF16tVyxA Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Mon Oct 26, 2026 at 1:26 PM EDT, Kiryl Shutsemau wrote: > On Mon, Oct 26, 2026 at 10:40:44AM +0100, David Hildenbrand (Arm) wrote: >> The final scan in shmem_undo_range() restarts after a successful split >> only if the original folio is no longer large. A nonuniform split can >> leave that folio large, so the scan skips the newly created folios. >> Hole punching then leaves pages within the hole allocated even though >> they could be discarded. >>=20 >> For example, a fault below the hole can allocate a 2 MiB folio after >> boundary handling. Punching a 1 MiB hole at offset 64 KiB splits the >> folio successfully but leaves the original folio at order 4. The scan >> continues past all 512 pages, leaving 2 MiB allocated instead of 1 MiB. >> The hole reads as zero, but the pages and their block charges remain. >>=20 >> Restart when the original folio is still in the mapping after partial >> truncation, identified by checking folio->mapping. If the helper >> removed the whole folio, no rescan is needed. >>=20 >> Fixes: 7460b470a131f ("mm/truncate: use folio_split() in truncate operat= ion") >> Cc: stable@vger.kernel.org >> Signed-off-by: David Hildenbrand (Arm) > > Acked-by: Kiryl Shutsemau (Meta) > > Do we want split state after truncate_inode_partial_folio() to be > communicated more explicit? ->mapping check works, but it might not be > obvious why. Just an idea for a follow up. Zhang Yi's truncate fix has done that. truncate_inode_partial_folio() returns true only if the folio is split[1]. His patches are in mm-stable but not upstreamed yet. [1] https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git/tree/mm/tru= ncate.c?h=3Dmm-stable#n248 --=20 Best Regards, Yan, Zi