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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B8A5EC352A4 for ; Mon, 10 Feb 2020 22:13:44 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7816020715 for ; Mon, 10 Feb 2020 22:13:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Gz7xVIYj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7816020715 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:40428 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j1HJH-0004yv-KU for qemu-devel@archiver.kernel.org; Mon, 10 Feb 2020 17:13:43 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52662) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j1HIQ-0004Sd-Vh for qemu-devel@nongnu.org; Mon, 10 Feb 2020 17:12:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j1HIP-0001e2-Rr for qemu-devel@nongnu.org; Mon, 10 Feb 2020 17:12:50 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:30836 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j1HIP-0001ZD-No for qemu-devel@nongnu.org; Mon, 10 Feb 2020 17:12:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581372767; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QOz4jUc9DBSbAVfQbhgVjaaSplcNNtLmmQV105ndPrw=; b=Gz7xVIYjxdejEdBuKwpbixG/MqB/61puKI8+ABp8pJrwFrETUT1goCVco9jQVhH+/qGjxv aJzA1bY2t9N0NcdqqhLbESLu5fe4nJN+XNMDb0qc16D/8lKH9f2S45Q//YGt7tUishU6WC DrrYd9h9gSRcUiqvaf34sYMW2ED8eOY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-93-ix0loyFpNxm6I5fLidTLxg-1; Mon, 10 Feb 2020 17:12:39 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 25C6CDB60; Mon, 10 Feb 2020 22:12:38 +0000 (UTC) Received: from localhost (unknown [10.36.118.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2B55B19C70; Mon, 10 Feb 2020 22:12:35 +0000 (UTC) Date: Mon, 10 Feb 2020 22:12:34 +0000 From: "Richard W.M. Jones" To: Eric Blake Subject: Re: Cross-project NBD extension proposal: NBD_INFO_INIT_STATE Message-ID: <20200210221234.GH3888@redhat.com> References: MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: ix0loyFpNxm6I5fLidTLxg-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vladimir Sementsov-Ogievskiy , Alberto Garcia , "qemu-block@nongnu.org" , QEMU , Max Reitz , "nbd@other.debian.org" , "libguestfs@redhat.com" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Feb 10, 2020 at 03:37:20PM -0600, Eric Blake wrote: > For now, only 2 of those 16 bits are defined: NBD_INIT_SPARSE (the > image has at least one hole) and NBD_INIT_ZERO (the image reads > completely as zero); the two bits are orthogonal and can be set > independently, although it is easy enough to see completely sparse > files with both bits set. I think I'm confused about the exact meaning of NBD_INIT_SPARSE. Do you really mean the whole image is sparse; or (as you seem to have said above) that there exists a hole somewhere in the image but we're not saying where it is and there can be non-sparse parts of the image? Rich. --=20 Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjon= es Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v