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[23.128.96.18]) by mx.google.com with ESMTP id hr7si6793781ejc.596.2021.03.13.08.26.04; Sat, 13 Mar 2021 08:26:27 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=Hv71HUzm; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233936AbhCMQYx (ORCPT + 99 others); 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-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-kernel@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!