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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 3A6F5C433C1 for ; Wed, 24 Mar 2021 16:37:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18C5461A12 for ; Wed, 24 Mar 2021 16:37:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234343AbhCXQhS (ORCPT ); Wed, 24 Mar 2021 12:37:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236012AbhCXQhO (ORCPT ); Wed, 24 Mar 2021 12:37:14 -0400 Received: from mail-ed1-x533.google.com (mail-ed1-x533.google.com [IPv6:2a00:1450:4864:20::533]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06329C0613DE for ; Wed, 24 Mar 2021 09:37:13 -0700 (PDT) Received: by mail-ed1-x533.google.com with SMTP id bx7so28358338edb.12 for ; Wed, 24 Mar 2021 09:37:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=F78F4/Kq+ndIvAG3q41JlNnbimm1afFKY1uPrkgKEKE=; b=CsDx6xAl1VtYRX8X8nlGVP72pS+Njf2eRG9UeLEcNYw/0GG+u51E8oRfnZj6k3/sNg aRLLF/mmJCW58czyShqa6WkR7qJxQwuiCLVxyrBpZ+TAPagZGTpDfa7+zl7Dur1DKlk4 B1AAACFL6xsj3ekCmh1gjol0o/QSp3xiwcbei6jwyZhVy3/cDah43fcg8J30O9ZE/PgR mQCXAHzOBzR2wsLGgkCG9GE3xk75u+tWfyPHSZJGznQsHqijxofg2L4Q1jPv+MKqUCHE RQjr95+R6I9EMKEYtmdWrRAb9fTP8P6XndMLkaPTVlg8oBOUifEZ/RsV84+JGEN92W79 y2cA== 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=F78F4/Kq+ndIvAG3q41JlNnbimm1afFKY1uPrkgKEKE=; b=BTxuvG4JTKqPyfQ4qganDoefMbRACP+o7FWAiISTUxfEP2BH0CMAK1DSQCkL419lSe KrPMOb2e+7/Z3K4g3MP/z7bTvnPNXswnfgBovaOxWr3hhUj6zM6hPwOPiGDrG9zE+PyO jcb1ayR36Te/sGNwiaBjdqL1fvJNOEH2vPDDQt7T+dhyWSCtiGZYsD7oRs1FDGym9Yrg NXu1WDXl69of9h5jT7bsw4JG5qSlG43fNKFEmXUcYD+S9hCc4tsBnRlUzbcvjU6dRCx+ rlEv3zspcM+0p1HhBsh7JtMeFblhP6qC2a8XC1dkMJK6rVauxPXZRqKTb86xXNU2zCBG UVGQ== X-Gm-Message-State: AOAM5331UtiCED9bPusZj1MQRf9GFRmYfa3bmEPxjmi/v3ZuHfOu8F8E 6hYf0K9j224AHRR96wAZuzmgOs94VzluBpWSyR8+Gw== X-Google-Smtp-Source: ABdhPJy0i6T+2AM1FhaOe2x1NOEA+VihVGm8Q0AyYdTDg9DUntxFo3NhisOlYTqdDwwzXOKs7/wWOwG2TBuN7zwJqD8= X-Received: by 2002:a05:6402:4301:: with SMTP id m1mr4548882edc.210.1616603832460; Wed, 24 Mar 2021 09:37:12 -0700 (PDT) MIME-Version: 1.0 References: <20210208105530.3072869-1-ruansy.fnst@cn.fujitsu.com> <20210208105530.3072869-2-ruansy.fnst@cn.fujitsu.com> <20210324074751.GA1630@lst.de> In-Reply-To: <20210324074751.GA1630@lst.de> From: Dan Williams Date: Wed, 24 Mar 2021 09:37:01 -0700 Message-ID: Subject: Re: [PATCH v3 01/11] pagemap: Introduce ->memory_failure() To: Christoph Hellwig Cc: "ruansy.fnst@fujitsu.com" , Linux Kernel Mailing List , linux-xfs , linux-nvdimm , Linux MM , linux-fsdevel , device-mapper development , "Darrick J. Wong" , david , Alasdair Kergon , Mike Snitzer , Goldwyn Rodrigues , "qi.fuli@fujitsu.com" , "y-goto@fujitsu.com" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Mar 24, 2021 at 12:48 AM Christoph Hellwig wrote: > > On Tue, Mar 23, 2021 at 07:19:28PM -0700, Dan Williams wrote: > > So I think the path forward is: > > > > - teach memory_failure() to allow for ranged failures > > > > - let interested drivers register for memory failure events via a > > blocking_notifier_head > > Eww. As I said I think the right way is that the file system (or > other consumer) can register a set of callbacks for opening the device. How does that solve the problem of the driver being notified of all pfn failure events? Today pmem only finds out about the ones that are notified via native x86 machine check error handling via a notifier (yes "firmware-first" error handling fails to do the right thing for the pmem driver), or the ones that are eventually reported via address range scrub, but only for the nvdimms that implement range scrubbing. memory_failure() seems a reasonable catch all point to route pfn failure events, in an arch independent way, to interested drivers. I'm fine swapping out dax_device blocking_notiier chains for your proposal, but that does not address all the proposed reworks in my list which are: - delete "drivers/acpi/nfit/mce.c" - teach memory_failure() to be able to communicate range failure - enable memory_failure() to defer to a filesystem that can say "critical metadata is impacted, no point in trying to do file-by-file isolation, bring the whole fs down". > I have a series I need to finish and send out to do that for block > devices. We probably also need the concept of a holder for the dax > device to make it work nicely, as otherwise we're going to have a bit > of a mess. Ok, I'll take a look at adding a holder. > > > This obviously does not solve Dave's desire to get this type of error > > reporting on block_devices, but I think there's nothing stopping a > > parallel notifier chain from being created for block-devices, but > > that's orthogonal to requirements and capabilities provided by > > dax-devices. > > FYI, my series could easily accomodate that if we ever get a block > driver that actually could report such errors. Sure, whatever we land for a dax_device could easily be adopted for a block device.