From nobody Mon Feb 9 12:43:02 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1506352007384812.6718847923105; Mon, 25 Sep 2017 08:06:47 -0700 (PDT) Received: from localhost ([::1]:42885 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dwUy2-0007xA-SM for importer@patchew.org; Mon, 25 Sep 2017 11:06:42 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54853) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dwUpB-00076R-Be for qemu-devel@nongnu.org; Mon, 25 Sep 2017 10:57:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dwUpA-0003vm-Dp for qemu-devel@nongnu.org; Mon, 25 Sep 2017 10:57:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13559) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dwUp2-0003qy-Q1; Mon, 25 Sep 2017 10:57:24 -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 BB4007EA91; Mon, 25 Sep 2017 14:57:23 +0000 (UTC) Received: from red.redhat.com (ovpn-124-97.rdu2.redhat.com [10.10.124.97]) by smtp.corp.redhat.com (Postfix) with ESMTP id F3585779D7; Mon, 25 Sep 2017 14:57:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com BB4007EA91 Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=eblake@redhat.com From: Eric Blake To: qemu-devel@nongnu.org Date: Mon, 25 Sep 2017 09:55:24 -0500 Message-Id: <20170925145526.32690-19-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 [10.5.110.28]); Mon, 25 Sep 2017 14:57:23 +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 18/20] qcow2: Switch store_bitmap_data() 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Now that we have adjusted the majority of the calls this function makes to be byte-based, it is easier to read the code if it makes passes over the image using bytes rather than sectors. iotests 165 was rather weak - on a default 64k-cluster image, where bitmap granularity also defaults to 64k bytes, a single cluster of the bitmap table thus covers (64*1024*8) bits which each cover 64k bytes, or 32G of image space. But the test only uses a 1G image, so it cannot trigger any more than one loop of the code in store_bitmap_data(); and it was writing to the first cluster. In order to test that we are properly aligning which portions of the bitmap are being written to the file, we really want to test a case where the first dirty bit returned by bdrv_dirty_iter_next() is not aligned to the start of a cluster, which we can do by modifying the test to write data that doesn't happen to fall in the first cluster of the image. Signed-off-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Fam Zheng Reviewed-by: John Snow --- v10: no change, add R-b v9: update iotests to show why aligning down is needed [Kevin], R-b dropped v8: no change v7: rebase to earlier change, make rounding of offset obvious (no semantic change, so R-b kept) [Kevin] v5-v6: no change v4: new patch --- block/qcow2-bitmap.c | 31 ++++++++++++++++--------------- tests/qemu-iotests/165 | 2 +- 2 files changed, 17 insertions(+), 16 deletions(-) diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 692ce0de88..df957c66d5 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -1072,10 +1072,9 @@ static uint64_t *store_bitmap_data(BlockDriverState = *bs, { int ret; BDRVQcow2State *s =3D bs->opaque; - int64_t sector; - uint64_t limit, sbc; + int64_t offset; + uint64_t limit; uint64_t bm_size =3D bdrv_dirty_bitmap_size(bitmap); - uint64_t bm_sectors =3D DIV_ROUND_UP(bm_size, BDRV_SECTOR_SIZE); const char *bm_name =3D bdrv_dirty_bitmap_name(bitmap); uint8_t *buf =3D NULL; BdrvDirtyBitmapIter *dbi; @@ -1100,18 +1099,22 @@ static uint64_t *store_bitmap_data(BlockDriverState= *bs, dbi =3D bdrv_dirty_iter_new(bitmap); buf =3D g_malloc(s->cluster_size); limit =3D bytes_covered_by_bitmap_cluster(s, bitmap); - sbc =3D limit >> BDRV_SECTOR_BITS; assert(DIV_ROUND_UP(bm_size, limit) =3D=3D tb_size); - while ((sector =3D bdrv_dirty_iter_next(dbi) >> BDRV_SECTOR_BITS) >=3D= 0) { - uint64_t cluster =3D sector / sbc; + while ((offset =3D bdrv_dirty_iter_next(dbi)) >=3D 0) { + uint64_t cluster =3D offset / limit; uint64_t end, write_size; int64_t off; - sector =3D cluster * sbc; - end =3D MIN(bm_sectors, sector + sbc); - write_size =3D bdrv_dirty_bitmap_serialization_size(bitmap, - sector * BDRV_SECTOR_SIZE, (end - sector) * BDRV_SECTOR_SIZE); + /* + * We found the first dirty offset, but want to write out the + * entire cluster of the bitmap that includes that offset, + * including any leading zero bits. + */ + offset =3D QEMU_ALIGN_DOWN(offset, limit); + end =3D MIN(bm_size, offset + limit); + write_size =3D bdrv_dirty_bitmap_serialization_size(bitmap, offset, + end - offset); assert(write_size <=3D s->cluster_size); off =3D qcow2_alloc_clusters(bs, s->cluster_size); @@ -1123,9 +1126,7 @@ static uint64_t *store_bitmap_data(BlockDriverState *= bs, } tb[cluster] =3D off; - bdrv_dirty_bitmap_serialize_part(bitmap, buf, - sector * BDRV_SECTOR_SIZE, - (end - sector) * BDRV_SECTOR_SIZE= ); + bdrv_dirty_bitmap_serialize_part(bitmap, buf, offset, end - offset= ); if (write_size < s->cluster_size) { memset(buf + write_size, 0, s->cluster_size - write_size); } @@ -1143,11 +1144,11 @@ static uint64_t *store_bitmap_data(BlockDriverState= *bs, goto fail; } - if (end >=3D bm_sectors) { + if (end >=3D bm_size) { break; } - bdrv_set_dirty_iter(dbi, end * BDRV_SECTOR_SIZE); + bdrv_set_dirty_iter(dbi, end); } *bitmap_table_size =3D tb_size; diff --git a/tests/qemu-iotests/165 b/tests/qemu-iotests/165 index 74d7b79a0b..a3932db3de 100755 --- a/tests/qemu-iotests/165 +++ b/tests/qemu-iotests/165 @@ -27,7 +27,7 @@ disk =3D os.path.join(iotests.test_dir, 'disk') disk_size =3D 0x40000000 # 1G # regions for qemu_io: (start, count) in bytes -regions1 =3D ((0, 0x100000), +regions1 =3D ((0x0fff00, 0x10000), (0x200000, 0x100000)) regions2 =3D ((0x10000000, 0x20000), --=20 2.13.5