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 9B8C6C433EF for ; Sat, 29 Jan 2022 02:14:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1E42E6B00D0; Fri, 28 Jan 2022 21:14:23 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 16E256B00D1; Fri, 28 Jan 2022 21:14:23 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F02786B00D2; Fri, 28 Jan 2022 21:14:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0114.hostedemail.com [216.40.44.114]) by kanga.kvack.org (Postfix) with ESMTP id DE3696B00D0 for ; Fri, 28 Jan 2022 21:14:22 -0500 (EST) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id A0019181AEF1F for ; Sat, 29 Jan 2022 02:14:22 +0000 (UTC) X-FDA: 79081705164.11.7DE4217 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf29.hostedemail.com (Postfix) with ESMTP id 3F872120006 for ; Sat, 29 Jan 2022 02:14:22 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 936AE61904; Sat, 29 Jan 2022 02:14:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AFBDCC340E7; Sat, 29 Jan 2022 02:14:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1643422461; bh=zSDHBCH3P+O3RfADVkHf3HrCwZThcIKMpyMGSUaHFTE=; h=Date:From:To:Subject:In-Reply-To:From; b=YFq1zRnBSOi8iwOaTSyjn5rD2tAyTEYdtTwEnzTspJ19oi4olrLgiiDocO5nWsrhH v0JaI4R4QK5Flt6XoGX5fHNAmAKvZ+ZZAdAw5JHO3CJOafKPJE6QmLaVDsYiK7rGFX 4mZzhXO+eeZw+MlYQzAw0XQSAXJw9wflOFjR4MqU= Date: Fri, 28 Jan 2022 18:14:20 -0800 From: Andrew Morton To: akpm@linux-foundation.org, dan.j.williams@intel.com, jane.chu@oracle.com, joao.m.martins@oracle.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, naoya.horiguchi@nec.com, songmuchun@bytedance.com, torvalds@linux-foundation.org Subject: [patch 3/7] memory-failure: fetch compound_head after pgmap_pfn_valid() Message-ID: <20220129021420.PgBIZm-q9%akpm@linux-foundation.org> In-Reply-To: <20220128181341.2103de95948608a65958ae40@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Stat-Signature: n1nko88jjzzqukefteqc9edebmbzn7e7 X-Rspam-User: nil Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=YFq1zRnB; spf=pass (imf29.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 3F872120006 X-HE-Tag: 1643422462-472212 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: From: Joao Martins Subject: memory-failure: fetch compound_head after pgmap_pfn_valid() memory_failure_dev_pagemap() at the moment assumes base pages (e.g. dax_lock_page()). For devmap with compound pages fetch the compound_head in case a tail page memory failure is being handled. Currently this is a nop, but in the advent of compound pages in dev_pagemap it allows memory_failure_dev_pagemap() to keep working. Without this fix memory-failure handling (i.e. MCEs on pmem) with device-dax configured namespaces will regress (and crash). Link: https://lkml.kernel.org/r/20211202204422.26777-2-joao.m.martins@oracle.com Reported-by: Jane Chu Signed-off-by: Joao Martins Reviewed-by: Naoya Horiguchi Reviewed-by: Dan Williams Reviewed-by: Muchun Song Signed-off-by: Andrew Morton --- mm/memory-failure.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/mm/memory-failure.c~memory-failure-fetch-compound_head-after-pgmap_pfn_valid +++ a/mm/memory-failure.c @@ -1596,6 +1596,12 @@ static int memory_failure_dev_pagemap(un } /* + * Pages instantiated by device-dax (not filesystem-dax) + * may be compound pages. + */ + page = compound_head(page); + + /* * Prevent the inode from being freed while we are interrogating * the address_space, typically this would be handled by * lock_page(), but dax pages do not use the page lock. This _