Received: by 2002:a25:8b91:0:0:0:0:0 with SMTP id j17csp1121333ybl; Sat, 18 Jan 2020 19:17:50 -0800 (PST) X-Google-Smtp-Source: APXvYqxJYBK14WzLEbuiJGd+jM1DFLaG1+8P3dYB2cuBBpcl9uj+77ZVGSNZ56BIBQNr9qM+1E+7 X-Received: by 2002:a9d:2dca:: with SMTP id g68mr10710897otb.150.1579403869989; Sat, 18 Jan 2020 19:17:49 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1579403869; cv=none; d=google.com; s=arc-20160816; b=kc2rSOqZ7ojZGS0iorH36mUjll4ftu6BUS34m5h/RHTlvdZ2cJDfDWulnI2xKvJlYw 1f8kXpDRDxq2q1epKsnFmUnW/RPRW7v2Jc3RPjxqdFQkbcTap6gqsgdBjcMXrWUCtFn2 /dCMv8FOFMhUKgrfm4reEWVyRcyymenlapkMXJ3TgHQRzbAASo1NWOsUVG/OjSwUuW4z nzEOmeuAW1YfFoaC0SyrRn8Dni5ACSnA7VkqLCfiaHlDcjZ0RVHcKoMqQXgf/N+IPaOl lol0LHw1tgY6YhUDIm9j/N/HbaZJx6A6lPjeuju5bwctTw1gcU3nXLzKea6Wwugrdk5N /gZg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:in-reply-to :mime-version:user-agent:date:message-id:from:references:cc:to :subject; bh=GlS1gdF0AXqx1cf2bq9tvnwRqC4sEY+5eaJ4yL6WfT4=; b=v1FNnx5k9uu9fqCcJF7yxbvB1JED9QmtLu4wHDcBGzvrezClhK9MRCgNcl6mMJIavv wyrfrJOoR9Sk3FIQqVVaJZpXQji1OIZEgkxQp81nhmRYU/rPwWXztTL3yWT+dFMRzF+w 5w15Q28q22JmmBn/SFEExAaCQjK38n99AQLx9HIUzw3idka7Fty4OFendv6GDue+ti6v Pkldu/XGZ+QQQJDV3HvmSEQUvZVVLVs1VJdTBc3R9nMZihFmTv/FRkilNF0BZrpjhuGt 8VF9PHzmEnvlgD7Zf+kG0Cyu8hidH61uPv4CcBrzYm9G8Yl2ptWEUoBIgXG92vOpArKj ZPgw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id f81si16536417oig.110.2020.01.18.19.17.37; Sat, 18 Jan 2020 19:17:49 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728721AbgASDPa (ORCPT + 99 others); Sat, 18 Jan 2020 22:15:30 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:9661 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726827AbgASDPa (ORCPT ); Sat, 18 Jan 2020 22:15:30 -0500 Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id B9E93D6B0EE9A4D5440E; Sun, 19 Jan 2020 11:15:27 +0800 (CST) Received: from [127.0.0.1] (10.173.220.96) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.439.0; Sun, 19 Jan 2020 11:15:19 +0800 Subject: Re: [RFC] iomap: fix race between readahead and direct write To: Gao Xiang CC: Matthew Wilcox , , , , , , , , References: <20200116063601.39201-1-yukuai3@huawei.com> <20200118230826.GA5583@bombadil.infradead.org> <20200119014213.GA16943@bombadil.infradead.org> <64d617cc-e7fe-6848-03bb-aab3498c9a07@huawei.com> <20200119030123.GA223124@architecture4> From: "yukuai (C)" Message-ID: Date: Sun, 19 Jan 2020 11:15:18 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20200119030123.GA223124@architecture4> Content-Type: text/plain; charset="gbk"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.173.220.96] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/1/19 11:01, Gao Xiang wrote: > IMO, if use_list == true, it will call read_pages -> .readpages > and go just like the current implementation. The problem is that in the current implementatin, iomap_next_page() add page to page cache and it is replaced with readahead_page() Thanks! Yu Kuai