From nobody Mon Feb 9 04:07:58 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.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 (zoho.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=1571154040; cv=none; d=zoho.com; s=zohoarc; b=FGVrZPDz+mKOSJN4Dwnb2One+pRIRNcTofUp70xHd+fEV6iZ7gGiy4//mGOykiXNLEwgr4Yeqgh8P7MBpuvoLPeRdL9xsPQXuNpqAvAwKuobZRXWOU9qxdfscJDhPfUaBp41FW5owiJl8AsndPo3iKFVOPj7eliLeY0ehtoP6NU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1571154040; 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=bb9ZdIeCIRGrOfF/Mvuj63LkDtjmwPtW8KRNa7nr2EA=; b=jRLxv8TVRcFAiZ7dn88XiJeZoZGYfb2IiOWNjYMzYLp32XSJ27ncJ45OSXY2V0T5NvES+ncWseKKzb2gzAZbN74vOjhXoeE8JMl+XXY5C3KsRrEVwk0QS2z21N4HrYnDqwA3AVT5ElJPHqIXr520YXvZKoIb01yghxzcY5pekDM= ARC-Authentication-Results: i=1; mx.zoho.com; dkim=fail; spf=pass (zoho.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 1571154040076963.334589089221; Tue, 15 Oct 2019 08:40:40 -0700 (PDT) Received: from localhost ([::1]:48970 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iKOw8-0004Mr-Gg for importer@patchew.org; Tue, 15 Oct 2019 11:40:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48482) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iKOhL-0003LR-2n for qemu-devel@nongnu.org; Tue, 15 Oct 2019 11:25:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iKOhJ-0003rO-P1 for qemu-devel@nongnu.org; Tue, 15 Oct 2019 11:25:18 -0400 Received: from fanzine.igalia.com ([178.60.130.6]:47175) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iKOhJ-0003c8-DC; Tue, 15 Oct 2019 11:25:17 -0400 Received: from 82-181-115-92.bb.dnainternet.fi ([82.181.115.92] helo=perseus.local) by fanzine.igalia.com with esmtpsa (Cipher TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim) id 1iKOge-0003aP-1Z; Tue, 15 Oct 2019 17:24:36 +0200 Received: from berto by perseus.local with local (Exim 4.92) (envelope-from ) id 1iKOfm-000617-He; Tue, 15 Oct 2019 18:23:42 +0300 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=bb9ZdIeCIRGrOfF/Mvuj63LkDtjmwPtW8KRNa7nr2EA=; b=ZnB3GS9FiAAEAz+z0kO0/S3Xl30LqcrPzQID/+Jr1WXL2mWhpTnOOULPUr93ZXvUBFvB/pPM1hrlc7j3Q/Yx/C471QX37h8c6P/i5S7VzXoofZZ2YWkIxEuytwT2U7ByKjZWUve5Gj1nauDHWlVh0naw5eVq+cOmOZw88aklTLpClszrd8oHcF7dDw89lRuCAfyyFwtJGyiomyX7xfhVEGrQGjyTJXoQeVqHQXlZbBWEZFeMq0GCb7siWvqcmlq5a3JaK6nX6+EwblczLFgmehGHNrW/i8PgDEewT2u4S/jTHe7GtQEU2xtceKrxnqmUJsqQPTUXhqbMtCg7pvnJPA==; From: Alberto Garcia To: qemu-devel@nongnu.org Subject: [RFC PATCH 02/23] qcow2: Split cluster_needs_cow() out of count_cow_clusters() Date: Tue, 15 Oct 2019 18:23:13 +0300 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 , "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" We are going to need it in other places. Signed-off-by: Alberto Garcia --- block/qcow2-cluster.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index fe2523ed66..f462e169c0 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1068,6 +1068,24 @@ static void calculate_l2_meta(BlockDriverState *bs, = uint64_t host_offset, QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight); } =20 +/* Returns true if writing to a cluster requires COW */ +static bool cluster_needs_cow(BlockDriverState *bs, uint64_t l2_entry) +{ + switch (qcow2_get_cluster_type(bs, l2_entry)) { + case QCOW2_CLUSTER_NORMAL: + if (l2_entry & QCOW_OFLAG_COPIED) { + return false; + } + case QCOW2_CLUSTER_UNALLOCATED: + case QCOW2_CLUSTER_COMPRESSED: + case QCOW2_CLUSTER_ZERO_PLAIN: + case QCOW2_CLUSTER_ZERO_ALLOC: + return true; + default: + abort(); + } +} + /* * Returns the number of contiguous clusters that can be used for an alloc= ating * write, but require COW to be performed (this includes yet unallocated s= pace, @@ -1080,25 +1098,11 @@ static int count_cow_clusters(BlockDriverState *bs,= int nb_clusters, =20 for (i =3D 0; i < nb_clusters; i++) { uint64_t l2_entry =3D be64_to_cpu(l2_slice[l2_index + i]); - QCow2ClusterType cluster_type =3D qcow2_get_cluster_type(bs, l2_en= try); - - switch(cluster_type) { - case QCOW2_CLUSTER_NORMAL: - if (l2_entry & QCOW_OFLAG_COPIED) { - goto out; - } + if (!cluster_needs_cow(bs, l2_entry)) { break; - case QCOW2_CLUSTER_UNALLOCATED: - case QCOW2_CLUSTER_COMPRESSED: - case QCOW2_CLUSTER_ZERO_PLAIN: - case QCOW2_CLUSTER_ZERO_ALLOC: - break; - default: - abort(); } } =20 -out: assert(i <=3D nb_clusters); return i; } --=20 2.20.1