{"id":815084,"url":"http://patchwork.ozlabs.org/api/1.2/patches/815084/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170918185819.5984-4-eblake@redhat.com/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.2/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20170918185819.5984-4-eblake@redhat.com>","list_archive_url":null,"date":"2017-09-18T18:58:02","name":"[v8,03/20] qcow2: Ensure bitmap serialization is aligned","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"472616d5a4f17ed17eb8882261a485c9ceeefc84","submitter":{"id":6591,"url":"http://patchwork.ozlabs.org/api/1.2/people/6591/?format=json","name":"Eric Blake","email":"eblake@redhat.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170918185819.5984-4-eblake@redhat.com/mbox/","series":[{"id":3711,"url":"http://patchwork.ozlabs.org/api/1.2/series/3711/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=3711","date":"2017-09-18T18:58:00","name":"make dirty-bitmap byte-based","version":8,"mbox":"http://patchwork.ozlabs.org/series/3711/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/815084/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/815084/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=nongnu.org\n\t(client-ip=2001:4830:134:3::11; helo=lists.gnu.org;\n\tenvelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n\treceiver=)","ext-mx06.extmail.prod.ext.phx2.redhat.com;\n\tdmarc=none (p=none dis=none) header.from=redhat.com","ext-mx06.extmail.prod.ext.phx2.redhat.com;\n\tspf=fail smtp.mailfrom=eblake@redhat.com"],"Received":["from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11])\n\t(using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xwwKZ6GH5z9s78\n\tfor ;\n\tTue, 19 Sep 2017 04:59:30 +1000 (AEST)","from localhost ([::1]:38347 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t)\n\tid 1du1GS-00028C-UZ\n\tfor incoming@patchwork.ozlabs.org; Mon, 18 Sep 2017 14:59:28 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:44068)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from ) id 1du1Fe-0001yT-JJ\n\tfor qemu-devel@nongnu.org; Mon, 18 Sep 2017 14:58:39 -0400","from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from ) id 1du1Fd-0006K5-La\n\tfor qemu-devel@nongnu.org; Mon, 18 Sep 2017 14:58:38 -0400","from mx1.redhat.com ([209.132.183.28]:42374)\n\tby eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)\n\t(Exim 4.71) (envelope-from )\n\tid 1du1Fb-0006Ha-G5; Mon, 18 Sep 2017 14:58:35 -0400","from smtp.corp.redhat.com\n\t(int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16])\n\t(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby mx1.redhat.com (Postfix) with ESMTPS id 7A0DF356DA;\n\tMon, 18 Sep 2017 18:58:34 +0000 (UTC)","from red.redhat.com (ovpn-124-97.rdu2.redhat.com [10.10.124.97])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id 466935C1A3;\n\tMon, 18 Sep 2017 18:58:32 +0000 (UTC)"],"DMARC-Filter":"OpenDMARC Filter v1.3.2 mx1.redhat.com 7A0DF356DA","From":"Eric Blake ","To":"qemu-devel@nongnu.org","Date":"Mon, 18 Sep 2017 13:58:02 -0500","Message-Id":"<20170918185819.5984-4-eblake@redhat.com>","In-Reply-To":"<20170918185819.5984-1-eblake@redhat.com>","References":"<20170918185819.5984-1-eblake@redhat.com>","X-Scanned-By":"MIMEDefang 2.79 on 10.5.11.16","X-Greylist":"Sender IP whitelisted, not delayed by milter-greylist-4.5.16\n\t(mx1.redhat.com [10.5.110.30]);\n\tMon, 18 Sep 2017 18:58:34 +0000 (UTC)","X-detected-operating-system":"by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic]\n\t[fuzzy]","X-Received-From":"209.132.183.28","Subject":"[Qemu-devel] [PATCH v8 03/20] qcow2: Ensure bitmap serialization is\n\taligned","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"kwolf@redhat.com, vsementsov@virtuozzo.com, jsnow@redhat.com,\n\tqemu-block@nongnu.org, Max Reitz ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t"},"content":"When subdividing a bitmap serialization, the code in hbitmap.c\nenforces that start/count parameters are aligned (except that\ncount can end early at end-of-bitmap). We exposed this required\nalignment through bdrv_dirty_bitmap_serialization_align(), but\nforgot to actually check that we comply with it.\n\nFortunately, qcow2 is never dividing bitmap serialization smaller\nthan one cluster (which is a minimum of 512 bytes); so we are\nalways compliant with the serialization alignment (which insists\nthat we partition at least 64 bits per chunk) because we are doing\nat least 4k bits per chunk.\n\nStill, it's safer to add an assertion (for the unlikely case that\nwe'd ever support a cluster smaller than 512 bytes, or if the\nhbitmap implementation changes what it considers to be aligned),\nrather than leaving bdrv_dirty_bitmap_serialization_align()\nwithout a caller.\n\nSigned-off-by: Eric Blake \nReviewed-by: John Snow \n\n---\nv5: no change\nv4: new patch\n---\n block/qcow2-bitmap.c | 7 +++++--\n 1 file changed, 5 insertions(+), 2 deletions(-)","diff":"diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c\nindex e8d3bdbd6e..b3ee4c794a 100644\n--- a/block/qcow2-bitmap.c\n+++ b/block/qcow2-bitmap.c\n@@ -274,10 +274,13 @@ static int free_bitmap_clusters(BlockDriverState *bs, Qcow2BitmapTable *tb)\n static uint64_t sectors_covered_by_bitmap_cluster(const BDRVQcow2State *s,\n const BdrvDirtyBitmap *bitmap)\n {\n- uint32_t sector_granularity =\n+ uint64_t sector_granularity =\n bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;\n+ uint64_t sbc = sector_granularity * (s->cluster_size << 3);\n\n- return (uint64_t)sector_granularity * (s->cluster_size << 3);\n+ assert(QEMU_IS_ALIGNED(sbc,\n+ bdrv_dirty_bitmap_serialization_align(bitmap)));\n+ return sbc;\n }\n\n /* load_bitmap_data\n","prefixes":["v8","03/20"]}