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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0405BC433F5 for ; Fri, 22 Apr 2022 21:27:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 665DD6B0073; Fri, 22 Apr 2022 17:27:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 615966B0074; Fri, 22 Apr 2022 17:27:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4DDA76B0075; Fri, 22 Apr 2022 17:27:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id 3B5D26B0073 for ; Fri, 22 Apr 2022 17:27:46 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 0AAFB4A8 for ; Fri, 22 Apr 2022 21:27:46 +0000 (UTC) X-FDA: 79385802132.04.7820245 Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) by imf10.hostedemail.com (Postfix) with ESMTP id 1DA1FC0032 for ; Fri, 22 Apr 2022 21:27:40 +0000 (UTC) Received: by mail-pl1-f172.google.com with SMTP id h12so9858023plf.12 for ; Fri, 22 Apr 2022 14:27:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=w9AKK/wGlnxig+lE3h4LHV/aZa9ukqQjCgIygmyWAnI=; b=68ZELSGoErna6Kx0I1rr70ZevaMAPMnUYlggojQeGdeNtet7Hum0m7txFWvhbVCPoh Lpfn1c1GUzjoDoqF3atTMDyB/W54WSq09ZqEMstjj/nD57yi3McP45zUESmlBRcMSayd RCzz4ipAytYtGQe71XITH8QJ3AOzILuXAM8yhmiGgJ7WF+oGlf5airqmyAOM2HGknwiH NL8jDL6gpoJPBQW7EeAY6wZ4C88AXehvjWq8bqkos1IivsjngJ9pqrOMVpnTljE1x58T I93xuOolWlJ6WC9weiHMQEfCyYC7FH5wSxSWXUOcug8i2eaQtc0PgYHeEI3sT7IioZIr TevA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=w9AKK/wGlnxig+lE3h4LHV/aZa9ukqQjCgIygmyWAnI=; b=lFT5RaS4Z1lVyQQI4srftc3vgWyRcbieqZ3MlnBzPtWx8aJCiiy7uOD4GiS80jkA55 xet1Zb7BnpMz8OgHJqRKEGEtMMYJ+wtjybaishvg1pN5SVQlWD2GwwTgNFfpvIP/hYME 8h23tuNszzyTWaQ15BB4GbaWX9mFACrVSJRJ1fmzJWt49MEbpOJVYrNviXraI3Om0vcj AemiShnOijjyyzW1gzbUXeBQa5C+MQVV/1QO7fG8wJwCdH2rnpD1UKWA3JeYugMwS6qx yZO+4E270cMHfGw/sgCNj6gCe78uyDUU7Yn8NS01nJ+QNz8XmJKpIWW1pFaHlBqaRpar gJxQ== X-Gm-Message-State: AOAM533oUT5KhY5ZYAsY/pcoisU2TEEtwAP8G4xruyqH8Pv8QLjDaVFW B4iPXaOri6kpNJNA0QsigeDsLQBW7tHxCsTDulvydg== X-Google-Smtp-Source: ABdhPJwBmyn23Epq/35EZiri4tm6JvqSiIIERB77yO45Op+oQcI+/5ahmZRwLntOQrNzhYN0N3NhjEndaBvuqb3gpmc= X-Received: by 2002:a17:902:7296:b0:14b:4bc6:e81 with SMTP id d22-20020a170902729600b0014b4bc60e81mr6342011pll.132.1650662863976; Fri, 22 Apr 2022 14:27:43 -0700 (PDT) MIME-Version: 1.0 References: <20220419045045.1664996-1-ruansy.fnst@fujitsu.com> <20220421012045.GR1544202@dread.disaster.area> <86cb0ada-208c-02de-dbc9-53c6014892c3@fujitsu.com> <20220421043502.GS1544202@dread.disaster.area> <20220421074653.GT1544202@dread.disaster.area> In-Reply-To: <20220421074653.GT1544202@dread.disaster.area> From: Dan Williams Date: Fri, 22 Apr 2022 14:27:32 -0700 Message-ID: Subject: Re: [PATCH v13 0/7] fsdax: introduce fs query to support reflink To: Dave Chinner Cc: Christoph Hellwig , Shiyang Ruan , Linux Kernel Mailing List , linux-xfs , Linux NVDIMM , Linux MM , linux-fsdevel , "Darrick J. Wong" , Jane Chu , Andrew Morton , Naoya Horiguchi Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=intel-com.20210112.gappssmtp.com header.s=20210112 header.b=68ZELSGo; dmarc=fail reason="No valid SPF, DKIM not aligned (relaxed)" header.from=intel.com (policy=none); spf=none (imf10.hostedemail.com: domain of dan.j.williams@intel.com has no SPF policy when checking 209.85.214.172) smtp.mailfrom=dan.j.williams@intel.com X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 1DA1FC0032 X-Rspam-User: X-Stat-Signature: t3wqjw83cbuuupnfk7npfygegqdocfqp X-HE-Tag: 1650662860-57308 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Apr 21, 2022 at 12:47 AM Dave Chinner wrote: > > On Wed, Apr 20, 2022 at 10:54:59PM -0700, Christoph Hellwig wrote: > > On Thu, Apr 21, 2022 at 02:35:02PM +1000, Dave Chinner wrote: > > > Sure, I'm not a maintainer and just the stand-in patch shepherd for > > > a single release. However, being unable to cleanly merge code we > > > need integrated into our local subsystem tree for integration > > > testing because a patch dependency with another subsystem won't gain > > > a stable commit ID until the next merge window is .... distinctly > > > suboptimal. > > > > Yes. Which is why we've taken a lot of mm patchs through other trees, > > sometimes specilly crafted for that. So I guess in this case we'll > > just need to take non-trivial dependencies into the XFS tree, and just > > deal with small merge conflicts for the trivial ones. > > OK. As Naoyo has pointed out, the first dependency/conflict Ruan has > listed looks trivial to resolve. > > The second dependency, OTOH, is on a new function added in the patch > pointed to. That said, at first glance it looks to be independent of > the first two patches in that series so I might just be able to pull > that one patch in and have that leave us with a working > fsdax+reflink tree. > > Regardless, I'll wait to see how much work the updated XFS/DAX > reflink enablement patchset still requires when Ruan posts it before > deciding what to do here. If it isn't going to be a merge > candidate, what to do with this patchset is moot because there's > little to test without reflink enabled... I do have a use case for this work absent the reflink work. Recall we had a conversation about how to communicate "dax-device has been ripped away from the fs" events and we ended up on the idea of reusing ->notify_failure(), but with the device's entire logical address range as the notification span. That will let me unwind and delete the PTE_DEVMAP infrastructure for taking extra device references to hold off device-removal. Instead ->notify_failure() arranges for all active DAX mappings to be invalidated and allow the removal to proceed especially since physical removal does not care about software pins.