From nobody Sun Feb 8 20:23:09 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=1577014958; cv=none; d=zohomail.com; s=zohoarc; b=CyOFLPPDQPFyJHc8hDAX99VV/9d/emvnNZgDeDLC+EM/QeSfrNu0u+r1RwbTT9Q5kBEfMFyfM6GGNi6sut9o9LEYO+Ww78F4iSI/U6AgYF8VpSNTsIl+0XTeFbEh1Oxfw0/aHi2P3sJoDQXqdFlJ1o+kBxsX+E3Vbzlbq6sBWDo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1577014958; 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=mgKJgIU5zdpoNf8COv2Q/Z566sYNJX9g2NTWfKTqyjc=; b=ec69oqslYe3BpKp/+yb8WJtLiWEjf9ZKjhKNqzYiCp65HfxFI36903K6ATmu/yVBEA5XO3ZfqxjEeFa3swFZZMbks6nOs8Iz0pdSoj+q6mpcGYqOqHK+GjOEQSDa7F9On+I7OQapMuey1+HeP7xBSTGQXs9C/M22SNr/dLn1G9k= 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 1577014958920485.58236711728205; Sun, 22 Dec 2019 03:42:38 -0800 (PST) Received: from localhost ([::1]:46668 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iizd7-0008Dk-Gv for importer@patchew.org; Sun, 22 Dec 2019 06:42:37 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41509) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iizYp-0002nx-Ea 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-0005bD-Py for qemu-devel@nongnu.org; Sun, 22 Dec 2019 06:38:11 -0500 Received: from fanzine.igalia.com ([178.60.130.6]:34953) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iizYn-0004Om-0f; 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-0005d4-DM; Sun, 22 Dec 2019 12:37:50 +0100 Received: from berto by perseus.local with local (Exim 4.92) (envelope-from ) id 1iizXu-0001VU-83; 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=mgKJgIU5zdpoNf8COv2Q/Z566sYNJX9g2NTWfKTqyjc=; b=kzfYZ1f2bQxMpPZ5FxAoj0XKe0fIsVzDcLLdw1vktTQmQJ0cPPUWsszp+z+y/biLizWLTyUY8uYx8k7ocq761KIFa9oQKIEkyYz8whsvrviQT10i09eROoPytqTYC3Glr7AjIkz6gZu16ak6pGBfKb5PQh3yQG2GX/PD5yTclxbHBAAcJFP+YOjehK65pol0utvuMryK16IreTNSOdsuNkwAcOjvHYIdyTVymQLAfuXZn2qyScl+7kwAyhRwjtpuoT969fTWVqNUIPNR9VE6EL7CF5oghwZdUdJ7oSbgSyDckoQuKfWf/rTY/ljrex3pidSMt4sGIwFA6PpHpdIDvw==; From: Alberto Garcia To: qemu-devel@nongnu.org Subject: [RFC PATCH v3 01/27] qcow2: Add calculate_l2_meta() Date: Sun, 22 Dec 2019 12:36:42 +0100 Message-Id: <2d53eae8fe9b9ab262daee45b662f631c3ba3899.1577014346.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" handle_alloc() creates a QCowL2Meta structure in order to update the image metadata and perform the necessary copy-on-write operations. This patch moves that code to a separate function so it can be used from other places. Signed-off-by: Alberto Garcia Reviewed-by: Max Reitz --- block/qcow2-cluster.c | 77 +++++++++++++++++++++++++++++-------------- 1 file changed, 53 insertions(+), 24 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 8982b7b762..617618dc54 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1019,6 +1019,56 @@ void qcow2_alloc_cluster_abort(BlockDriverState *bs,= QCowL2Meta *m) QCOW2_DISCARD_NEVER); } =20 +/* + * For a given write request, create a new QCowL2Meta structure, add + * it to @m and the BDRVQcow2State.cluster_allocs list. + * + * @host_cluster_offset points to the beginning of the first cluster. + * + * @guest_offset and @bytes indicate the offset and length of the + * request. + * + * If @keep_old is true it means that the clusters were already + * allocated and will be overwritten. If false then the clusters are + * new and we have to decrease the reference count of the old ones. + */ +static void calculate_l2_meta(BlockDriverState *bs, + uint64_t host_cluster_offset, + uint64_t guest_offset, unsigned bytes, + QCowL2Meta **m, bool keep_old) +{ + BDRVQcow2State *s =3D bs->opaque; + unsigned cow_start_from =3D 0; + unsigned cow_start_to =3D offset_into_cluster(s, guest_offset); + unsigned cow_end_from =3D cow_start_to + bytes; + unsigned cow_end_to =3D ROUND_UP(cow_end_from, s->cluster_size); + unsigned nb_clusters =3D size_to_clusters(s, cow_end_from); + QCowL2Meta *old_m =3D *m; + + *m =3D g_malloc0(sizeof(**m)); + **m =3D (QCowL2Meta) { + .next =3D old_m, + + .alloc_offset =3D host_cluster_offset, + .offset =3D start_of_cluster(s, guest_offset), + .nb_clusters =3D nb_clusters, + + .keep_old_clusters =3D keep_old, + + .cow_start =3D { + .offset =3D cow_start_from, + .nb_bytes =3D cow_start_to - cow_start_from, + }, + .cow_end =3D { + .offset =3D cow_end_from, + .nb_bytes =3D cow_end_to - cow_end_from, + }, + }; + + qemu_co_queue_init(&(*m)->dependent_requests); + QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight); +} + /* * 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, @@ -1417,35 +1467,14 @@ static int handle_alloc(BlockDriverState *bs, uint6= 4_t guest_offset, uint64_t requested_bytes =3D *bytes + offset_into_cluster(s, guest_off= set); int avail_bytes =3D nb_clusters << s->cluster_bits; int nb_bytes =3D MIN(requested_bytes, avail_bytes); - QCowL2Meta *old_m =3D *m; - - *m =3D g_malloc0(sizeof(**m)); - - **m =3D (QCowL2Meta) { - .next =3D old_m, - - .alloc_offset =3D alloc_cluster_offset, - .offset =3D start_of_cluster(s, guest_offset), - .nb_clusters =3D nb_clusters, - - .keep_old_clusters =3D keep_old_clusters, - - .cow_start =3D { - .offset =3D 0, - .nb_bytes =3D offset_into_cluster(s, guest_offset), - }, - .cow_end =3D { - .offset =3D nb_bytes, - .nb_bytes =3D avail_bytes - nb_bytes, - }, - }; - qemu_co_queue_init(&(*m)->dependent_requests); - QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight); =20 *host_offset =3D alloc_cluster_offset + offset_into_cluster(s, guest_o= ffset); *bytes =3D MIN(*bytes, nb_bytes - offset_into_cluster(s, guest_offset)= ); assert(*bytes !=3D 0); =20 + calculate_l2_meta(bs, alloc_cluster_offset, guest_offset, *bytes, + m, keep_old_clusters); + return 1; =20 fail: --=20 2.20.1