From patchwork Thu Mar 28 16:40:30 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 232114 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 93BAC2C007C for ; Fri, 29 Mar 2013 03:46:33 +1100 (EST) Received: from localhost ([::1]:41081 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ULFyB-0004M9-Ma for incoming@patchwork.ozlabs.org; Thu, 28 Mar 2013 12:46:31 -0400 Received: from eggs.gnu.org ([208.118.235.92]:46642) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ULFtG-00069O-AU for qemu-devel@nongnu.org; Thu, 28 Mar 2013 12:41:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ULFtA-0002GJ-3l for qemu-devel@nongnu.org; Thu, 28 Mar 2013 12:41:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52103) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ULFt9-0002GE-R1 for qemu-devel@nongnu.org; Thu, 28 Mar 2013 12:41:20 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r2SGfJpj014363 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 28 Mar 2013 12:41:19 -0400 Received: from localhost (ovpn-112-23.ams2.redhat.com [10.36.112.23]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id r2SGfH3Y008820; Thu, 28 Mar 2013 12:41:18 -0400 From: Stefan Hajnoczi To: Date: Thu, 28 Mar 2013 17:40:30 +0100 Message-Id: <1364488837-15916-17-git-send-email-stefanha@redhat.com> In-Reply-To: <1364488837-15916-1-git-send-email-stefanha@redhat.com> References: <1364488837-15916-1-git-send-email-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , Anthony Liguori , Stefan Hajnoczi Subject: [Qemu-devel] [PATCH 16/23] qcow2: handle_copied(): Get rid of keep_clusters parameter X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Kevin Wolf Now *bytes is used to return the length of the area that can be written to without performing an allocation or COW. Signed-off-by: Kevin Wolf Signed-off-by: Stefan Hajnoczi --- block/qcow2-cluster.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index d640328..5e5465d 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -831,19 +831,17 @@ static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset, * * -errno: in error cases * - * TODO Get rid of keep_clusters parameter - * TODO Make bytes behave like described above * TODO Make non-zero host_offset behave like describe above */ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset, - uint64_t *host_offset, uint64_t *bytes, QCowL2Meta **m, - unsigned int *keep_clusters) + uint64_t *host_offset, uint64_t *bytes, QCowL2Meta **m) { BDRVQcowState *s = bs->opaque; int l2_index; uint64_t cluster_offset; uint64_t *l2_table; unsigned int nb_clusters; + unsigned int keep_clusters; int ret, pret; trace_qcow2_handle_copied(qemu_coroutine_self(), guest_offset, *host_offset, @@ -873,17 +871,19 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset, && (cluster_offset & QCOW_OFLAG_COPIED)) { /* We keep all QCOW_OFLAG_COPIED clusters */ - *keep_clusters = + keep_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size, &l2_table[l2_index], 0, QCOW_OFLAG_COPIED | QCOW_OFLAG_ZERO); - assert(*keep_clusters <= nb_clusters); + assert(keep_clusters <= nb_clusters); + + *bytes = MIN(*bytes, + keep_clusters * s->cluster_size + - offset_into_cluster(s, guest_offset)); ret = 1; } else { - *keep_clusters = 0; cluster_offset = 0; - ret = 0; } @@ -1168,16 +1168,19 @@ again: * TODO: Consider cluster_offset if set in step 1c. */ uint64_t tmp_bytes = cur_bytes; - ret = handle_copied(bs, offset, &cluster_offset, &tmp_bytes, m, - &keep_clusters); + ret = handle_copied(bs, offset, &cluster_offset, &tmp_bytes, m); if (ret < 0) { return ret; } else if (ret) { + keep_clusters = + size_to_clusters(s, tmp_bytes + offset_into_cluster(s, offset)); nb_clusters -= keep_clusters; if (!*host_offset) { *host_offset = cluster_offset; } + } else { + keep_clusters = 0; } /* If there is something left to allocate, do that now */