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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 81716C33CB3 for ; Fri, 17 Jan 2020 10:51:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 593A92053B for ; Fri, 17 Jan 2020 10:51:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UcD7lZoq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726688AbgAQKvK (ORCPT ); Fri, 17 Jan 2020 05:51:10 -0500 Received: from mail-io1-f67.google.com ([209.85.166.67]:44824 "EHLO mail-io1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726196AbgAQKvK (ORCPT ); Fri, 17 Jan 2020 05:51:10 -0500 Received: by mail-io1-f67.google.com with SMTP id b10so25460153iof.11; Fri, 17 Jan 2020 02:51:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=zPZgl/q3vIfnV2rf1MzWjb5AG5EqjQJkR1tLQ7+HViE=; b=UcD7lZoqdCKmmyidin5ILgMNLGITtnWVYg5U6qgBN3OKJX9tnuHAfbgsm8JJqgjRhx zocBJnxCLiRNbzmMpNQkCA9HZmsA65yWUcLaPWycg3x6g/HQQplFsvlb3N92Gj+D391I saehgHhAJBVNwhrQzHQsn6UL2Hro4bjML1DZsWY7Q5CDRgV9YbjLOI0ZkEaCngGQ0KPD CpDX4S3btG+Nbu6WAZTJEH5O409++Wycn/hxUG+a+ifCjIg/M6S7fd60qWGKcNwghhEc WZ5PUXt2oGFCQFKzcDvY8KhZvdmim0nBgYyEz/R2OKHh+mwN1TvhPaaBnMFXVs5ti/CH J0+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=zPZgl/q3vIfnV2rf1MzWjb5AG5EqjQJkR1tLQ7+HViE=; b=DjPO5M655c3REglHsgTKTRI/TXU6Poi7LoCcPa6oIDt8INzCZErnIcNeVWyr3EHzmY vcuacI5k1mdxe5EoUVuKOA5kFo3x2QwUSjT8B8Mc7pjJ4UVAohPZthueH6Z/H2rnTB+i KoUWvU4N2Jb0/s7YRHx/FXzg25uQkFnQ58PQOgOAvZxf6Oid6YLpAcsWrcpHump0t8Ij aApiZT5K67rTqR3lqdDxs9qJydP3KxdzkDbUEJVOj87nCxOFrGroPHM5UaTAvrNYCyim o6W989sYoLsup0NKYwsXFE6t3ygW+bZ+kVhpKv3kTvn/VFEJibk6hDfFqJZb5lwWOcwc feaQ== X-Gm-Message-State: APjAAAVjo6gATj3gpMVF754Izb0EVr8z284OxCI11tW2C1olJ0exlWgD 74Qyjdcmyhi3Uhc5zaUK5o94JZMXS4q5bPzKUno= X-Google-Smtp-Source: APXvYqysK2eTf49GiafHKvgR56da2irbgyCZ+FgusY/y8P/HNItR2DbQCVbsqL5oLa8EtQK2WbVUzonQKs1oPXlLUkU= X-Received: by 2002:a5e:9907:: with SMTP id t7mr30947541ioj.72.1579258269524; Fri, 17 Jan 2020 02:51:09 -0800 (PST) MIME-Version: 1.0 References: <20190829131034.10563-1-jack@suse.cz> In-Reply-To: <20190829131034.10563-1-jack@suse.cz> From: Amir Goldstein Date: Fri, 17 Jan 2020 12:50:58 +0200 Message-ID: Subject: Re: [PATCH 0/3 v2] xfs: Fix races between readahead and hole punching To: Jan Kara Cc: linux-xfs , Linux MM , "Darrick J. Wong" , Boaz Harrosh , linux-fsdevel , Matthew Wilcox , Jens Axboe Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, Aug 29, 2019 at 4:10 PM Jan Kara wrote: > > Hello, > > this is a patch series that addresses a possible race between readahead and > hole punching Amir has discovered [1]. The first patch makes madvise(2) to > handle readahead requests through fadvise infrastructure, the third patch > then adds necessary locking to XFS to protect against the race. Note that > other filesystems need similar protections but e.g. in case of ext4 it isn't > so simple without seriously regressing mixed rw workload performance so > I'm pushing just xfs fix at this moment which is simple. > Jan, Could you give a quick status update about the state of this issue for ext4 and other fs. I remember some solutions were discussed. Perhaps this could be a good topic for a cross track session in LSF/MM? Aren't the challenges posed by this race also relevant for RWF_UNCACHED? Thanks, Amir.