From patchwork Mon Sep 25 14:55:22 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 818286 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3y16lL5lG6z9t67 for ; Tue, 26 Sep 2017 01:02:54 +1000 (AEST) Received: from localhost ([::1]:42870 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dwUuK-0004FB-PS for incoming@patchwork.ozlabs.org; Mon, 25 Sep 2017 11:02:52 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54671) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dwUos-0006qS-Ck for qemu-devel@nongnu.org; Mon, 25 Sep 2017 10:57:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dwUor-0003mS-CF for qemu-devel@nongnu.org; Mon, 25 Sep 2017 10:57:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40488) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dwUoh-0003hQ-8c; Mon, 25 Sep 2017 10:57:03 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 36FEB4E4C3; Mon, 25 Sep 2017 14:57:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 36FEB4E4C3 Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=eblake@redhat.com Received: from red.redhat.com (ovpn-124-97.rdu2.redhat.com [10.10.124.97]) by smtp.corp.redhat.com (Postfix) with ESMTP id EC9077053E; Mon, 25 Sep 2017 14:56:59 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Date: Mon, 25 Sep 2017 09:55:22 -0500 Message-Id: <20170925145526.32690-17-eblake@redhat.com> In-Reply-To: <20170925145526.32690-1-eblake@redhat.com> References: <20170925145526.32690-1-eblake@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 25 Sep 2017 14:57:02 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v10 16/20] qcow2: Switch qcow2_measure() to byte-based iteration X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, famz@redhat.com, qemu-block@nongnu.org, Max Reitz , jsnow@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" This is new code, but it is easier to read if it makes passes over the image using bytes rather than sectors (and will get easier in the future when bdrv_get_block_status is converted to byte-based). Signed-off-by: Eric Blake Reviewed-by: John Snow Reviewed-by: Kevin Wolf Reviewed-by: Fam Zheng --- v7: tweak constant given to MIN (no semantic change, R-b kept) [Kevin] v6: separate bug fix to earlier patch v5: new patch --- block/qcow2.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index d33fb3ecdd..4cb3189ae5 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -3648,20 +3648,19 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs, */ required = virtual_size; } else { - int cluster_sectors = cluster_size / BDRV_SECTOR_SIZE; - int64_t sector_num; + int64_t offset; int pnum = 0; - for (sector_num = 0; - sector_num < ssize / BDRV_SECTOR_SIZE; - sector_num += pnum) { - int nb_sectors = MIN(ssize / BDRV_SECTOR_SIZE - sector_num, - BDRV_REQUEST_MAX_SECTORS); + for (offset = 0; offset < ssize; + offset += pnum * BDRV_SECTOR_SIZE) { + int nb_sectors = MIN(ssize - offset, + BDRV_REQUEST_MAX_BYTES) / BDRV_SECTOR_SIZE; BlockDriverState *file; int64_t ret; ret = bdrv_get_block_status_above(in_bs, NULL, - sector_num, nb_sectors, + offset >> BDRV_SECTOR_BITS, + nb_sectors, &pnum, &file); if (ret < 0) { error_setg_errno(&local_err, -ret, @@ -3674,12 +3673,11 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs, } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) == (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) { /* Extend pnum to end of cluster for next iteration */ - pnum = ROUND_UP(sector_num + pnum, cluster_sectors) - - sector_num; + pnum = (ROUND_UP(offset + pnum * BDRV_SECTOR_SIZE, + cluster_size) - offset) >> BDRV_SECTOR_BITS; /* Count clusters we've seen */ - required += (sector_num % cluster_sectors + pnum) * - BDRV_SECTOR_SIZE; + required += offset % cluster_size + pnum * BDRV_SECTOR_SIZE; } } }