From patchwork Fri Jan 31 17:44:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 11360347 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 30931924 for ; Fri, 31 Jan 2020 17:51:40 +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 06AA5206D5 for ; Fri, 31 Jan 2020 17:51:40 +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="Zvypeutc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 06AA5206D5 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:57304 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ixaSB-0005Ka-66 for patchwork-qemu-devel@patchwork.kernel.org; Fri, 31 Jan 2020 12:51:39 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41740) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ixaLu-0003Ws-3J for qemu-devel@nongnu.org; Fri, 31 Jan 2020 12:45:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ixaLt-0004yi-5i for qemu-devel@nongnu.org; Fri, 31 Jan 2020 12:45:10 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:27447 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ixaLt-0004yD-2C for qemu-devel@nongnu.org; Fri, 31 Jan 2020 12:45:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580492708; 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=EOGOsxpR0p2OgwGamNOhNFGeIiUOgsZlr2K/1g0z2zM=; b=Zvypeutc971fTZln/w2lNWhtUJ63KXIetcIT+I38L60JX8UjGWAi+H+lad5MN4rIuxMF2t ztFJ7MAeD8N+TRrI3gsVoDWwJCFvBaNTTzJRek9ht1iAZpIQxOeN++pAxrrgVSfj65V+bf X7uY+hgxDReLY7exu391jd2Z+HGWVwE= 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-339-F9DMh8VkMUimTRjx07R7XA-1; Fri, 31 Jan 2020 12:44:57 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 23576800D48; Fri, 31 Jan 2020 17:44:56 +0000 (UTC) Received: from blue.redhat.com (ovpn-116-181.phx2.redhat.com [10.3.116.181]) by smtp.corp.redhat.com (Postfix) with ESMTP id A56E87FB60; Fri, 31 Jan 2020 17:44:55 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Subject: [PATCH 14/17] qcow2: Expose all zero bit through .bdrv_known_zeroes Date: Fri, 31 Jan 2020 11:44:33 -0600 Message-Id: <20200131174436.2961874-15-eblake@redhat.com> In-Reply-To: <20200131174436.2961874-1-eblake@redhat.com> References: <20200131174436.2961874-1-eblake@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: F9DMh8VkMUimTRjx07R7XA-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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: david.edmondson@oracle.com, Kevin Wolf , qemu-block@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" Now that qcow2 images have a way to track when the contents are known to be all zero, it is worth exposing this to clients such as qemu-img convert. (Of course, until the next patch wires up qcow2 to actually set the bit, this patch has no immediate effect; however, keeping it as a separate patch allows for an easier revert when testing if the bit makes a difference in qemu-img behavior). Signed-off-by: Eric Blake --- block/qcow2.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/qcow2.c b/block/qcow2.c index 20cce9410c84..3f61d806a14b 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -4938,6 +4938,9 @@ static int qcow2_known_zeroes(BlockDriverState *bs) * therefore enough to check the first one. */ preallocated = s->l1_size > 0 && s->l1_table[0] != 0; + if (s->autoclear_features & QCOW2_AUTOCLEAR_ALL_ZERO) { + r |= BDRV_ZERO_OPEN; + } if (qemu_in_coroutine()) { qemu_co_mutex_unlock(&s->lock); }