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=-2.8 required=3.0 tests=BAYES_00,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 E9797C433E6 for ; Sat, 13 Mar 2021 16:25:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA06A64F26 for ; Sat, 13 Mar 2021 16:25:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233570AbhCMQYx (ORCPT ); Sat, 13 Mar 2021 11:24:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233478AbhCMQYi (ORCPT ); Sat, 13 Mar 2021 11:24:38 -0500 Received: from mail-yb1-xb34.google.com (mail-yb1-xb34.google.com [IPv6:2607:f8b0:4864:20::b34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61BCBC061574; Sat, 13 Mar 2021 08:24:38 -0800 (PST) Received: by mail-yb1-xb34.google.com with SMTP id u3so28716383ybk.6; Sat, 13 Mar 2021 08:24:38 -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:content-transfer-encoding; bh=aXi6zxmykvKGGuEUIknBGQuu/CrpF+OFk8aqg1g8+Js=; b=Hv71HUzmf0Lv3L07Y9vPI88fr2tkUa/1JbFZGy51jjbh9n4cRQ+P6rLbvPAhZMLbg5 ixsUkRYdDUhei4YCiRy0287CIkP8b3Jg9TpHICyCGV2xDgcQFoYiRrPDp0LcPbNyPobt e2mB8WjIyZJjUgnIK3eEg9rREEgBthIupmC5k7TJkMd1BdMNglR5MTBljFc4WnZL0Tv/ 2A5yFWAf2SP7q2tspr8wPFHgGP1dhWKjLEJrKe1jxyEujMO/6QhrAuiX6efY9Q0tZhFG jbv3PaYMyafnqAK7BZW4C9hHl2HDt27Z0jCW48yq0cRe9cKlFDPeNt9KBY4Z6kTHjtIk 4+5Q== 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=aXi6zxmykvKGGuEUIknBGQuu/CrpF+OFk8aqg1g8+Js=; b=RWpJp9ontZOvRMncYQydzhgd/kmxrCW8sA2Ss7LRhtcfOdDRN05N0BMdgwxBp9lcqV 9RisfygBqY7VUHuBXgutd6LSgESo5NHywEPfFqyIquxFfPd60o++gNEwYxYFPqUgzt2J /UBPjHmaNb1A5kaNZIqtdN9YU5HjXDwaWNIpUkzVH9RUW8JzOB2p9ByW3gi6kjp9LKzQ gkPddsfWFIbCzF42F35daAAkB1Oxww0Jkh7Oi7QtNzGDLvMXoBptAcY0TuqUD9XMv06s Pj9of01etDCrGKMA4YkZgIMK308rmtskcCeS8WK0OO8A1KJvBQYuWzCGyi00TOUl80Jq 2nWw== X-Gm-Message-State: AOAM533KP5HXB3hBoclYsfK8ZYpxe/wiTlfCU/uEShCW3vneppsIz5/b oyTaM5gkLl9XCr50q3SQAOIr+c+Bg32n0WP3kms= X-Google-Smtp-Source: ABdhPJwtKc3ckDh1wM2gREfAQUcazj9bOTqT8gJ/CC1jACL5d+N8mbIM5sD/vFtR/QEb1ipgGC33qgcC6cjdF7XgPjg= X-Received: by 2002:a25:424f:: with SMTP id p76mr27228411yba.109.1615652676401; Sat, 13 Mar 2021 08:24:36 -0800 (PST) MIME-Version: 1.0 References: <20210226002030.653855-1-ruansy.fnst@fujitsu.com> <20210310130227.GN3479805@casper.infradead.org> <20210310142159.kudk7q2ogp4yqn36@fiona> <20210310142643.GQ3479805@casper.infradead.org> In-Reply-To: From: Neal Gompa Date: Sat, 13 Mar 2021 11:24:00 -0500 Message-ID: Subject: Re: [PATCH v2 00/10] fsdax,xfs: Add reflink&dedupe support for fsdax To: Adam Borowski Cc: Matthew Wilcox , Goldwyn Rodrigues , Shiyang Ruan , Linux Kernel Mailing List , linux-xfs , linux-nvdimm , linux-fsdevel , "Darrick J. Wong" , Jan Kara , Al Viro , Btrfs BTRFS , ocfs2-devel@oss.oracle.com, david , Christoph Hellwig Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Sat, Mar 13, 2021 at 8:09 AM Adam Borowski wrote: > > On Wed, Mar 10, 2021 at 02:26:43PM +0000, Matthew Wilcox wrote: > > On Wed, Mar 10, 2021 at 08:21:59AM -0600, Goldwyn Rodrigues wrote: > > > DAX on btrfs has been attempted[1]. Of course, we could not > > > > But why? A completeness fetish? I don't understand why you decided > > to do this work. > > * xfs can shapshot only single files, btrfs entire subvolumes > * btrfs-send|receive > * enumeration of changed parts of a file > XFS cannot do snapshots since it lacks metadata COW. XFS reflinking is primarily for space efficiency. --=20 =E7=9C=9F=E5=AE=9F=E3=81=AF=E3=81=84=E3=81=A4=E3=82=82=E4=B8=80=E3=81=A4=EF= =BC=81/ Always, there's only one truth!