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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 82A57C33C9B for ; Tue, 7 Jan 2020 02:10:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 62C7920715 for ; Tue, 7 Jan 2020 02:10:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727501AbgAGCJ7 (ORCPT ); Mon, 6 Jan 2020 21:09:59 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:41500 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727250AbgAGCJ6 (ORCPT ); Mon, 6 Jan 2020 21:09:58 -0500 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id C36D1DC97F6905CA2BEE; Tue, 7 Jan 2020 10:09:55 +0800 (CST) Received: from [127.0.0.1] (10.173.220.96) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.439.0; Tue, 7 Jan 2020 10:09:45 +0800 Subject: Re: [PATCH 2/2] xfs: fix stale data exposure problem when punch hole, collapse range or zero range across a delalloc extent To: "Darrick J. Wong" CC: , , , , , , , , , References: <20191226134721.43797-1-yukuai3@huawei.com> <20191226134721.43797-3-yukuai3@huawei.com> <20200106215755.GB472651@magnolia> From: "yukuai (C)" Message-ID: Date: Tue, 7 Jan 2020 10:09:44 +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: <20200106215755.GB472651@magnolia> 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 2020/1/7 5:57, Darrick J. Wong wrote: > So your solution is to split the delalloc reservation to constrain the > allocation to the range that's being operated on? Yes, I'm trying to split delalloc reservation. > > If so, I think a better solution (at least from the perspective of > reducing fragmentation) would be to map the extent unwritten and force a > post-writeback conversion[1] but I got shot down for performance reasons > the last time I suggested that. I'm wondering if spliting delalloc reservation have the same performance issue. Thanks! Yu Kuai