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 X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B519C433E0 for ; Tue, 12 Jan 2021 02:56:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E79D122CF7 for ; Tue, 12 Jan 2021 02:56:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733151AbhALC4f (ORCPT ); Mon, 11 Jan 2021 21:56:35 -0500 Received: from mail.cn.fujitsu.com ([183.91.158.132]:57297 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728044AbhALC4d (ORCPT ); Mon, 11 Jan 2021 21:56:33 -0500 X-IronPort-AV: E=Sophos;i="5.79,340,1602518400"; d="scan'208";a="103383793" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 12 Jan 2021 10:55:38 +0800 Received: from G08CNEXMBPEKD05.g08.fujitsu.local (unknown [10.167.33.204]) by cn.fujitsu.com (Postfix) with ESMTP id C0A054CE602D; Tue, 12 Jan 2021 10:55:35 +0800 (CST) Received: from irides.mr (10.167.225.141) by G08CNEXMBPEKD05.g08.fujitsu.local (10.167.33.204) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 12 Jan 2021 10:55:36 +0800 Subject: Re: [PATCH 04/10] mm, fsdax: Refactor memory-failure handler for dax mapping To: Jan Kara CC: , , , , , , , , , , , , , References: <20201230165601.845024-1-ruansy.fnst@cn.fujitsu.com> <20201230165601.845024-5-ruansy.fnst@cn.fujitsu.com> <20210106154132.GC29271@quack2.suse.cz> From: Ruan Shiyang Message-ID: <75164044-bfdf-b2d6-dff0-d6a8d56d1f62@cn.fujitsu.com> Date: Tue, 12 Jan 2021 10:55:34 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20210106154132.GC29271@quack2.suse.cz> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.167.225.141] X-ClientProxiedBy: G08CNEXCHPEKD04.g08.fujitsu.local (10.167.33.200) To G08CNEXMBPEKD05.g08.fujitsu.local (10.167.33.204) X-yoursite-MailScanner-ID: C0A054CE602D.AADE7 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@cn.fujitsu.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/1/6 下午11:41, Jan Kara wrote: > On Thu 31-12-20 00:55:55, Shiyang Ruan wrote: >> The current memory_failure_dev_pagemap() can only handle single-mapped >> dax page for fsdax mode. The dax page could be mapped by multiple files >> and offsets if we let reflink feature & fsdax mode work together. So, >> we refactor current implementation to support handle memory failure on >> each file and offset. >> >> Signed-off-by: Shiyang Ruan > > Overall this looks OK to me, a few comments below. > >> --- >> fs/dax.c | 21 +++++++++++ >> include/linux/dax.h | 1 + >> include/linux/mm.h | 9 +++++ >> mm/memory-failure.c | 91 ++++++++++++++++++++++++++++++++++----------- >> 4 files changed, 100 insertions(+), 22 deletions(-) ... >> >> @@ -345,9 +348,12 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, >> } >> >> tk->addr = page_address_in_vma(p, vma); >> - if (is_zone_device_page(p)) >> - tk->size_shift = dev_pagemap_mapping_shift(p, vma); >> - else >> + if (is_zone_device_page(p)) { >> + if (is_device_fsdax_page(p)) >> + tk->addr = vma->vm_start + >> + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); > > It seems strange to use 'pgoff' for dax pages and not for any other page. > Why? I'd rather pass correct pgoff from all callers of add_to_kill() and > avoid this special casing... Because one fsdax page can be shared by multiple pgoffs. I have to pass each pgoff in each iteration to calculate the address in vma (for tk->addr). Other kinds of pages don't need this. They can get their unique address by calling "page_address_in_vma()". So, I added this fsdax case here. This patchset only implemented the fsdax case, other cases also need to be added here if to be implemented. -- Thanks, Ruan Shiyang. > >> + tk->size_shift = dev_pagemap_mapping_shift(p, vma, tk->addr); >> + } else >> tk->size_shift = page_shift(compound_head(p)); >> >> /* >> @@ -495,7 +501,7 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill, >> if (!page_mapped_in_vma(page, vma)) >> continue; >> if (vma->vm_mm == t->mm) >> - add_to_kill(t, page, vma, to_kill); >> + add_to_kill(t, page, NULL, 0, vma, to_kill); >> } >> } >> read_unlock(&tasklist_lock); >> @@ -505,24 +511,19 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill, >> /* >> * Collect processes when the error hit a file mapped page. >> */ >> -static void collect_procs_file(struct page *page, struct list_head *to_kill, >> - int force_early) >> +static void collect_procs_file(struct page *page, struct address_space *mapping, >> + pgoff_t pgoff, struct list_head *to_kill, int force_early) >> { >> struct vm_area_struct *vma; >> struct task_struct *tsk; >> - struct address_space *mapping = page->mapping; >> - pgoff_t pgoff; >> >> i_mmap_lock_read(mapping); >> read_lock(&tasklist_lock); >> - pgoff = page_to_pgoff(page); >> for_each_process(tsk) { >> struct task_struct *t = task_early_kill(tsk, force_early); >> - >> if (!t) >> continue; >> - vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, >> - pgoff) { >> + vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { >> /* >> * Send early kill signal to tasks where a vma covers >> * the page but the corrupted page is not necessarily >> @@ -531,7 +532,7 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, >> * to be informed of all such data corruptions. >> */ >> if (vma->vm_mm == t->mm) >> - add_to_kill(t, page, vma, to_kill); >> + add_to_kill(t, page, mapping, pgoff, vma, to_kill); >> } >> } >> read_unlock(&tasklist_lock); >> @@ -550,7 +551,8 @@ static void collect_procs(struct page *page, struct list_head *tokill, >> if (PageAnon(page)) >> collect_procs_anon(page, tokill, force_early); >> else >> - collect_procs_file(page, tokill, force_early); >> + collect_procs_file(page, page->mapping, page_to_pgoff(page), > > Why not use page_mapping() helper here? It would be safer for THPs if they > ever get here... > > Honza >