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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2D367C25B76 for ; Wed, 5 Jun 2024 08:14:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5dN0PkdKFOlVgXYg+yfnjvKHUUq2vSP7/QUgMWYomfk=; b=Pss7AYzpj2s6GUjmYWn5VDnXFz evEz/kvkL/qocrLS3MsfNKqPipnUsoEL5fKltNiCfYDZyvWVNDiWYrPmqdnwr5vQfJaah+qb1iVNj 4EX8rNTzLKTDeGgdm+/f/H64BX6k7CzhzSyuZGJdmE0TMMRJHSQej+2gJX9bF+BrX2XzdF8xK3uYf W84TiuEeIv0YTqZMeaDxIGrfnh6Y4eZY8RGJdEeerW132hRL9rCU409UDFi2lqcPF0bPEO4tbHV1K fQENjjNINjagvhgsKa+TBZfgVvWHJwEfJuh2CjOqYaoZfPbQH+CMcsEui7nW0xyyb6L9wxDIaaH76 tryuiLHQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sElmj-000000057vb-2FQ2; Wed, 05 Jun 2024 08:14:17 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sElmg-000000057uU-3wNL for linux-nvme@lists.infradead.org; Wed, 05 Jun 2024 08:14:16 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 14B8567373; Wed, 5 Jun 2024 10:14:08 +0200 (CEST) Date: Wed, 5 Jun 2024 10:14:07 +0200 From: Christoph Hellwig To: Damien Le Moal Cc: Hannes Reinecke , Christoph Hellwig , Nitesh Shetty , Jens Axboe , Jonathan Corbet , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Keith Busch , Sagi Grimberg , Chaitanya Kulkarni , Alexander Viro , Christian Brauner , Jan Kara , martin.petersen@oracle.com, bvanassche@acm.org, david@fromorbit.com, damien.lemoal@opensource.wdc.com, anuj20.g@samsung.com, joshi.k@samsung.com, nitheshshetty@gmail.com, gost.dev@samsung.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, dm-devel@lists.linux.dev, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v20 00/12] Implement copy offload support Message-ID: <20240605081407.GA18688@lst.de> References: <20240604043242.GC28886@lst.de> <393edf87-30c9-48b8-b703-4b8e514ac4d9@suse.de> <5441b256-494a-4344-89fd-ee8c5a073f8b@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5441b256-494a-4344-89fd-ee8c5a073f8b@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240605_011415_141558_DA954842 X-CRM114-Status: GOOD ( 12.25 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Jun 04, 2024 at 04:39:25PM +0900, Damien Le Moal wrote: > > But I wasn't aware that this approach is limited to copying within a > > single block devices; that would be quite pointless indeed. > > Not pointless for any FS doing CoW+Rebalancing of block groups (e.g. btrfs) and > of course GC for FSes on zoned devices. But for this use case, an API allowing > multiple sources and one destination would be better. Yes.