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,FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 F38A0C43334 for ; Tue, 4 Sep 2018 10:46:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD4A42077C for ; Tue, 4 Sep 2018 10:46:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UQO3n7T7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AD4A42077C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727449AbeIDPKj (ORCPT ); Tue, 4 Sep 2018 11:10:39 -0400 Received: from mail-oi0-f53.google.com ([209.85.218.53]:32968 "EHLO mail-oi0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726339AbeIDPKj (ORCPT ); Tue, 4 Sep 2018 11:10:39 -0400 Received: by mail-oi0-f53.google.com with SMTP id 8-v6so5844566oip.0; Tue, 04 Sep 2018 03:46:05 -0700 (PDT) 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:content-transfer-encoding; bh=f6NbJvvMPr7hm3DLYs+rN0f7QhdTzq4mmEPYt7M55EU=; b=UQO3n7T7fAnpdbRRGjaKoGO43oUwBeZ4KTidAeTXgFc6MOsba6YjqpCxHlOsMj0kot p4WqVQZdnk5CWvdRV0PF1s2cQv4o77iG5WL9ajAgIoZ5JQ5vG+kh7ZIieshmzzAYDiLS uQfaUgmEWXqlZfBsUkGB5xGw2P3R612yLf/dd0YUb2h7xET7vKELTFgvg7TSRLg5TIlT DhaxdtboxDGBwdIFLQSDodLXBxSNAski43bdZzKAIbUUippU7ezQuivixAXZBKrPOSbd szeAWpobROB19Qmeq4QoEjPnc3hkp32U+3q5JJW/9nprRTD3XEfab3Besvea1xp4VaaK eRAg== 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:content-transfer-encoding; bh=f6NbJvvMPr7hm3DLYs+rN0f7QhdTzq4mmEPYt7M55EU=; b=lnhBQdsgOx9yna4dWNixEJtUbYk8gvvS1Mtgn1NEPMYP4232xDSyo/Wvyn8UHppV+p +K9//vUf3HfDbzetBXIxSjw0/y5nh4gHA53mo6L/TphggChEO5sbjvDtA1jl00YWkZ6o WwBCQuoVm1R2XgoZ3mVV0NwTbLqbdElL4B5POSCgQIE5W2hqerxToZkbSMP32EnDkinV C2lYXxEAz5eLHKB/R/15Yu4ddoCzMZ5iD6dtmcsCQEYZSOcG1mkH87vgB/FhLlZ7Xlut vsoIUSFKXO3GkVtEPvEozwk+wVNTiS1IgAfuULjK/Yd2aMaNEM9ibWSMQ0TA5YUnDv3G K4Gw== X-Gm-Message-State: APzg51C7p1g+WCxVtLekmdNndnLdC9a9eadg6WmFmXEEGrhQEiN5IRhM ZStsgnMbBxq6u65Gfn1u2s2OPgQIrnoZkXyGDM4= X-Google-Smtp-Source: ANB0VdaM11L6neQJDGwRISlxtl22rGVTyeZiJqdPhdlbedoi8Mv9IrpWjph4nBLPo/Lt/QWzItOUzxhIkq2xSlrHUSw= X-Received: by 2002:aca:bec2:: with SMTP id o185-v6mr22025769oif.22.1536057965469; Tue, 04 Sep 2018 03:46:05 -0700 (PDT) MIME-Version: 1.0 References: <20180904075347.GH11854@BitWizard.nl> <20180904092938.GJ11854@BitWizard.nl> In-Reply-To: <20180904092938.GJ11854@BitWizard.nl> From: =?UTF-8?B?54Sm5pmT5Yas?= Date: Tue, 4 Sep 2018 18:45:54 +0800 Message-ID: Subject: Re: POSIX violation by writeback error To: R.E.Wolff@bitwizard.nl Cc: jlayton@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 4, 2018 at 5:29 PM Rogier Wolff wrote: > > On Tue, Sep 04, 2018 at 04:58:59PM +0800, =E7=84=A6=E6=99=93=E5=86=AC wro= te: > > > As for suggestion, maybe the error flag of inode/mapping, or the entire= inode > > should not be evicted if there was an error. That hopefully won't take = much > > memory. On extreme conditions, where too much error inode requires stay= ing > > in memory, maybe we should panic rather then spread the error. > > Again you are hoping it will fit in memory. In an extreme case it > won't fit in memory. Tyring to come up with heuristics about when to > remember and when to forget such things from the past is very > difficult. The key point is to report errors, not to hide it from user space to prevent further errors/damage, and that is also what POSIX wants. And, storing inode/mapping/error_flag in memory is quite different from storing the data itself. They are tiny and only increase per inode rather than per error page. > > Think of my comments as: "it's harder than you think", not as "can't > be done". > > Roger. > > -- > ** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2600998 *= * > ** Delftechpark 26 2628 XH Delft, The Netherlands. KVK: 27239233 *= * > *-- BitWizard writes Linux device drivers for any device you may have! --= * > The plan was simple, like my brother-in-law Phil. But unlike > Phil, this plan just might work.