From nobody Mon Feb 9 01:50:58 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1577015151; cv=none; d=zohomail.com; s=zohoarc; b=APeXZ9BCwd8z9SSsBxeLD1G2DBnx3CB7kmf5HlcOqEJGb6qTsHHIdVeVHu9YAND7IGAbcAOerk3NUXqkF4BF/ddvXo9novGKTjp+LYg3ipUi6X8gM3FK6QAzbBK48ZPQgFfL9E1xXpq7DEkoLVXRV2Mc+MKjJGLgDjUxkIy8Ics= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1577015151; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=flXGfZhQJSs04qAtnGSSBaswVOGe2VgIccmH2UkpbYk=; b=ObAxvi9clAGaJPHsj1LxLMCN+NcMqtnTgRK4KLb90dCSzvC3OfSSHnaYLYeF/DY4QhJZxN9N5zkKZAz/eAfx6ESfsMnlfhZC7XvfhmuLDaS4XJknRgpX1hDZ0CPjQGzQk6hmhAvBkEQdSxWF6MgyKCF6mLs+t1eAZfMxvd4MS1U= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1577015151429400.61033516839063; Sun, 22 Dec 2019 03:45:51 -0800 (PST) Received: from localhost ([::1]:46738 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iizgD-0003J4-Dx for importer@patchew.org; Sun, 22 Dec 2019 06:45:49 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41486) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iizYp-0002nu-5t for qemu-devel@nongnu.org; Sun, 22 Dec 2019 06:38:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iizYn-0005b8-QI for qemu-devel@nongnu.org; Sun, 22 Dec 2019 06:38:10 -0500 Received: from fanzine.igalia.com ([178.60.130.6]:34950) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iizYn-0004Ol-24; Sun, 22 Dec 2019 06:38:09 -0500 Received: from [80.30.182.172] (helo=perseus.local) by fanzine.igalia.com with esmtpsa (Cipher TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim) id 1iizYU-0005d9-I6; Sun, 22 Dec 2019 12:37:51 +0100 Received: from berto by perseus.local with local (Exim 4.92) (envelope-from ) id 1iizXu-0001Vg-Dy; Sun, 22 Dec 2019 12:37:14 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=flXGfZhQJSs04qAtnGSSBaswVOGe2VgIccmH2UkpbYk=; b=je/j4XVdtVvdzmKBrFcgE4znmE0Z65JNYPayialAGpHAURG2h6iebYZsyMzAOjSUkuP+rl4R0GLRmMLJTrgbZcTsnhTuYUw+xbtcRKhTUJ4IhzjnrqQkZpqzsK1vfDylJ3NCnMqvZCt9zlHl1S7ppnZHTr/M0KESvQ+d+Iks/BQz2cZwvKQ3phg+5i++5PH3kAerR0HT3jHkwTsB+fMAs4JC9OTOVwDoiFOR60vgXnAvd+9vSD7Ph1LRdQ0odM0hlewQkwm9er/+EzI6CcQHV8NWYbG6+Gu4zzuDvV/lhpFsf++JiLl5RC/LxtMwJy+yhzNIneyz5ZxD0os272eOSA==; From: Alberto Garcia To: qemu-devel@nongnu.org Subject: [RFC PATCH v3 07/27] qcow2: Add subcluster-related fields to BDRVQcow2State Date: Sun, 22 Dec 2019 12:36:48 +0100 Message-Id: X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] [fuzzy] X-Received-From: 178.60.130.6 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: Kevin Wolf , Anton Nefedov , Alberto Garcia , qemu-block@nongnu.org, Max Reitz , Vladimir Sementsov-Ogievskiy , "Denis V . Lunev" Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" This patch adds the following new fields to BDRVQcow2State: - subclusters_per_cluster: Number of subclusters in a cluster - subcluster_size: The size of each subcluster, in bytes - subcluster_bits: No. of bits so 1 << subcluster_bits =3D subcluster_size Images without subclusters are treated as if they had exactly one, with subcluster_size =3D cluster_size. Signed-off-by: Alberto Garcia Reviewed-by: Max Reitz --- block/qcow2.c | 5 +++++ block/qcow2.h | 5 +++++ 2 files changed, 10 insertions(+) diff --git a/block/qcow2.c b/block/qcow2.c index 3866b47946..cbd857e9c7 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1378,6 +1378,11 @@ static int coroutine_fn qcow2_do_open(BlockDriverSta= te *bs, QDict *options, } } =20 + s->subclusters_per_cluster =3D + has_subclusters(s) ? QCOW_MAX_SUBCLUSTERS_PER_CLUSTER : 1; + s->subcluster_size =3D s->cluster_size / s->subclusters_per_cluster; + s->subcluster_bits =3D ctz32(s->subcluster_size); + /* Check support for various header values */ if (header.refcount_order > 6) { error_setg(errp, "Reference count entry width too large; may not " diff --git a/block/qcow2.h b/block/qcow2.h index 1db3fc5dbc..941330cfc9 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -78,6 +78,8 @@ /* The cluster reads as all zeros */ #define QCOW_OFLAG_ZERO (1ULL << 0) =20 +#define QCOW_MAX_SUBCLUSTERS_PER_CLUSTER 32 + #define MIN_CLUSTER_BITS 9 #define MAX_CLUSTER_BITS 21 =20 @@ -284,6 +286,9 @@ typedef struct BDRVQcow2State { int cluster_bits; int cluster_size; int l2_slice_size; + int subcluster_bits; + int subcluster_size; + int subclusters_per_cluster; int l2_bits; int l2_size; int l1_size; --=20 2.20.1