From nobody Sun Feb 8 21:06:03 2026 Delivered-To: importer@patchew.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=1590332962; cv=none; d=zohomail.com; s=zohoarc; b=Gt1DPBBnILrLfJfbEYexTEr3KztwaAKzp2KtO6T6AyDzMlHDnzUQKh0Yy26++/pM+F++T1TK7URc63n0UWdSisIYPVySIufZ/LQy6Bp7P/QZ5VW+NRa3Iub9+SDxCB6CgSpHE2/FQi0Yo8xVxul3kqlg+cmzDcJjY4vctRrYmyI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1590332962; 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=x44WykpORUb7jKPsPZokuc5MU7JgoaeSdWXwYoNGUz0=; b=jH/htTsHAA/hylmwqUVWzcEqkWyVHrwblxytPL9AWFA3mTgcLMpckSButczuw5p7gXkFkd8tjhvuTCCQddZT0lFeSx1huEAiBjsOz1wRIQK28oTpl34QLPqvg25xOSdu+zHMWY97HOf2AnxRFUeavAqbgl99EECtQfO2Cp0mB/E= 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 1590332962578920.702904164016; Sun, 24 May 2020 08:09:22 -0700 (PDT) Received: from localhost ([::1]:58446 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jcsFd-0007sw-A7 for importer@patchew.org; Sun, 24 May 2020 11:09:21 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45874) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jcs03-0003Aq-97; Sun, 24 May 2020 10:53:15 -0400 Received: from fanzine.igalia.com ([178.60.130.6]:38009) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jcrzy-0002lm-BZ; Sun, 24 May 2020 10:53:14 -0400 Received: from [81.0.38.199] (helo=perseus.local) by fanzine.igalia.com with esmtpsa (Cipher TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim) id 1jcrzF-0007GS-Sm; Sun, 24 May 2020 16:52:26 +0200 Received: from berto by perseus.local with local (Exim 4.92) (envelope-from ) id 1jcryu-0005K6-Nf; Sun, 24 May 2020 16:52:04 +0200 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=x44WykpORUb7jKPsPZokuc5MU7JgoaeSdWXwYoNGUz0=; b=GmpDxivcYFmaVplhVU0ZNNkQz328a1Fk2c6D2bkl6gAKpqT/i7vRTGdYFo5lwISIWmGuIzSYxh5lQ0vkNMKax+keWKkyoFs9OZCbe8RemXmvXB0PU4+b5CQhDYq//tmGs1t3OeFOZBPc2phC8Ey3R4twvDRmVAqB8VCSI/maTPRiu1dcQmSmynxOtBp1FWCq50+Zqtxl0PP2ml580VRGzZ67Tbn61Lr5bwC3NipdmRFinY5PcC8t0CPDUILeDkgmF2C4s/pMwyYkOgIxxExU/suAHC6YEK07j/a30YpHXSdBut6WH3BgfSRd6e+et5jJ7C0RrW8dixQ3dMakHZy6xg==; From: Alberto Garcia To: qemu-devel@nongnu.org Subject: [PATCH v6 04/32] qcow2: Split cluster_needs_cow() out of count_cow_clusters() Date: Sun, 24 May 2020 16:51:24 +0200 Message-Id: <049ff3d0ced4aec304010bb1919e84f986fdee2f.1590331741.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 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; Received-SPF: pass client-ip=178.60.130.6; envelope-from=berto@igalia.com; helo=fanzine.igalia.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/24 10:52:20 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x (no timestamps) [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action 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 , Vladimir Sementsov-Ogievskiy , Alberto Garcia , qemu-block@nongnu.org, Derek Su , Max Reitz 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 61ad638bdc..80f9787461 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1087,6 +1087,24 @@ 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, @@ -1099,25 +1117,11 @@ 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