From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id 8319224C068; Tue, 4 Mar 2025 16:04:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741104270; cv=none; b=S9zVGtX8KdoXggCWe4dsKRfzPeaefd0utdaD+o2ASOySpXnjjz7esMTXqNi19WoCP+UBTagtR3Qyh7E9Uumhce0d5fBVxpi1Po+2qkNfSQfQ0PQZxZcfqe2wto7tWJ+6/VREejJiToilJ6/9f5CWv/EoaLN1ABZZ9i8L4Vpygco= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741104270; c=relaxed/simple; bh=ud1f9gtjRhGurv6nqr2dtZPRMXm/Btg/3VvzbrXikGM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jpcxpVDOpn/3t3Q1RoeKfOq7W9kuPvScKrRCHVKhvdE+A8GU5Cz5BhWWBYGoKfiMMNEtNtSPB2TER0aGOO3gRfbosM6ou6dadzRQa7Hvyl777rDxuobmIWIvrSoyL/HFUQAl7nfeTMKSq4jTyL+S4BqSmVi4g8J9+kK/lXfZteg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=RGcz5KqL; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="RGcz5KqL" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=eFi854rHWXf77vFMrT7dM4VCDWhDDka/F/tms7maNYw=; b=RGcz5KqLj1zSKWF2P0i8OeZu68 Moep0YmW16SdXfmfOCDbMMLWEsvcPgZrXzKKSGz8LIShiyJdOzoNvUExtUJtlnp0P20mRu7dofcd4 SUSDuwJ/k2hHgFVLKX4GRX7rlBOra+wSCl1XXE/Z0nP4c5wyqQxXN8153Rx3yHyl2U9vFYJrySXzA wevTZL+ujwICRbcMydVZUGtD7XxJt+W2fDRzE5ImWzkEp9KAqUFgX06vbs+3WhtQoIr1aQ/VeX1Ky gUYOuJvZK3fVK/Q7TLdCe50zbsDeRreSYBTMrueCuVPVOGZyo6NCSPGHSvfDUAbwZ12zqH6j3gIo+ QZd+8hUw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tpUkt-00000005LJm-0lBm; Tue, 04 Mar 2025 16:04:27 +0000 Date: Tue, 4 Mar 2025 08:04:27 -0800 From: Christoph Hellwig To: Heinz Mauelshagen Cc: Christoph Hellwig , Mikulas Patocka , Jens Axboe , Jooyung Han , Alasdair Kergon , Mike Snitzer , zkabelac@redhat.com, dm-devel@lists.linux.dev, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] the dm-loop target Message-ID: References: <7d6ae2c9-df8e-50d0-7ad6-b787cb3cfab4@redhat.com> <8adb8df2-0c75-592d-bc3e-5609bb8de8d8@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Tue, Mar 04, 2025 at 03:50:36PM +0100, Heinz Mauelshagen wrote: > Seems to have a loop target to add respective mapped device semantics, the > way to go is to design it using VFS API to get it upstream. > > Won't help the Android use case requested by Google thus they'll have to > stick to their multi-segment linear mapped approach to achieve their > performance goals unless they want to support dm-loop OOT to make their > life easier on immutable file backings. What are "the performance goals" and what is in the way of achieving them? This thread has massively blown up but no one has even tried to explain what the thing tries to address.