From nobody Sun Feb 8 21:21:13 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=1577016061; cv=none; d=zohomail.com; s=zohoarc; b=iRnoFGmfQcoDgNdYZga8vGN2tazmu5TJnZVTRF2yayljCxxfcyM3PbkvSkwaEpAZJ15nA3P4Sg2pi0NtxRV/XEL2FTRn3vRCMM2KkRhaeD3IfRWui7SkGUNlmZtUKypQnAtZSob1+aJBVuzpZJ0PLIxcxj2RfzHe8UxVmNmn7g0= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1577016061; 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=G5UHWiqSgBi5RZLPT5B93DOloDP71FGfaNpqmuSGnG0=; b=jnHisS85GbyNy6MtDWBD2Wiy4Kgyp/fbSXA18ia+qjJ/gQ/spcR8uow7WcSvWVdV+9ryz5T00VaTBdTV1gnP2suVh6gaxGJvBVVAVE3kh6xpP8RC+xW2PmdI3IJhd+2B2FDCi5qPoV9fU+IJPjJZXOC2XT/u6/USneVLbuwOyLc= 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 1577016061914711.5151115611039; Sun, 22 Dec 2019 04:01:01 -0800 (PST) Received: from localhost ([::1]:47052 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iizuu-0001hp-IZ for importer@patchew.org; Sun, 22 Dec 2019 07:01:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:43809) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iizZ9-0003NG-Th for qemu-devel@nongnu.org; Sun, 22 Dec 2019 06:38:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iizZ8-0006q8-BP for qemu-devel@nongnu.org; Sun, 22 Dec 2019 06:38:31 -0500 Received: from fanzine.igalia.com ([178.60.130.6]:34946) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iizZ7-0004Oo-TB; Sun, 22 Dec 2019 06:38:30 -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-0005d3-Co; Sun, 22 Dec 2019 12:37:50 +0100 Received: from berto by perseus.local with local (Exim 4.92) (envelope-from ) id 1iizXu-0001VW-93; 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=G5UHWiqSgBi5RZLPT5B93DOloDP71FGfaNpqmuSGnG0=; b=H42spux6danfMP+XOXoVaoaqRZ6pRSPVMBoK4906zLYGXJI3IGg9VYtRNiFyT6T2ellNEpj1Ya7hLfydZBXz+tCDAtsBqSnya/gOIRMKMhN9sOiZgZz3aq87vTHreFhzR+D2GnMQuJPT2/us2FPzX/CiyahHJYv1DPBSZnZZRqTKKjQ3JIuBZeVgWErqSjG8VOvusmnUkD7cwNNSr2USZSbaVrXxmw4qm8gtgx2qUvsWrflPRS4M5l4vei89fLZry3vDfeYK6J1Mf4+yHHUYGDBF3zOO8EyHxv/COnZ7roL0ULwz5z35RjbV/kkLdOL0s1XlS5ZWpOqT9URvp/sNng==; From: Alberto Garcia To: qemu-devel@nongnu.org Subject: [RFC PATCH v3 02/27] qcow2: Split cluster_needs_cow() out of count_cow_clusters() Date: Sun, 22 Dec 2019 12:36:43 +0100 Message-Id: <7c18e5c5faed0fd0a630bcaeeac7b175fe4918a7.1577014346.git.berto@igalia.com> 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" We are going to need it in other places. Signed-off-by: Alberto Garcia Reviewed-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Max Reitz --- 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 617618dc54..e078bddcc2 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1069,6 +1069,24 @@ static void calculate_l2_meta(BlockDriverState *bs, 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, @@ -1081,25 +1099,11 @@ 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