From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89649C47404 for ; Fri, 11 Oct 2019 21:28:32 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5C4DB218AC for ; Fri, 11 Oct 2019 21:28:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5C4DB218AC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:57152 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iJ2Sc-00046Y-Vb for qemu-devel@archiver.kernel.org; Fri, 11 Oct 2019 17:28:31 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54992) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iJ2QI-00027Y-My for qemu-devel@nongnu.org; Fri, 11 Oct 2019 17:26:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iJ2QH-0000zA-67 for qemu-devel@nongnu.org; Fri, 11 Oct 2019 17:26:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57136) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iJ2QE-0000yB-Ih; Fri, 11 Oct 2019 17:26:02 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B302D5AFDE; Fri, 11 Oct 2019 21:26:01 +0000 (UTC) Received: from probe.bos.redhat.com (dhcp-17-173.bos.redhat.com [10.18.17.173]) by smtp.corp.redhat.com (Postfix) with ESMTP id 541561EC; Fri, 11 Oct 2019 21:26:00 +0000 (UTC) From: John Snow To: Peter Maydell , qemu-devel@nongnu.org Subject: [PULL 01/19] util/hbitmap: strict hbitmap_reset Date: Fri, 11 Oct 2019 17:25:32 -0400 Message-Id: <20191011212550.27269-2-jsnow@redhat.com> In-Reply-To: <20191011212550.27269-1-jsnow@redhat.com> References: <20191011212550.27269-1-jsnow@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 11 Oct 2019 21:26:01 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 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: Fam Zheng , Kevin Wolf , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, Juan Quintela , libvir-list@redhat.com, John Snow , "Dr. David Alan Gilbert" , Max Reitz , Stefan Hajnoczi , Markus Armbruster Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Vladimir Sementsov-Ogievskiy hbitmap_reset has an unobvious property: it rounds requested region up. It may provoke bugs, like in recently fixed write-blocking mode of mirror: user calls reset on unaligned region, not keeping in mind that there are possible unrelated dirty bytes, covered by rounded-up region and information of this unrelated "dirtiness" will be lost. Make hbitmap_reset strict: assert that arguments are aligned, allowing only one exception when @start + @count =3D=3D hb->orig_size. It's needed to comfort users of hbitmap_next_dirty_area, which cares about hb->orig_size. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Max Reitz Message-Id: <20190806152611.280389-1-vsementsov@virtuozzo.com> [Maintainer edit: Max's suggestions from on-list. --js] Signed-off-by: John Snow --- include/qemu/hbitmap.h | 5 +++++ tests/test-hbitmap.c | 2 +- util/hbitmap.c | 4 ++++ 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h index 4afbe6292e3..1bf944ca3d1 100644 --- a/include/qemu/hbitmap.h +++ b/include/qemu/hbitmap.h @@ -132,6 +132,11 @@ void hbitmap_set(HBitmap *hb, uint64_t start, uint64= _t count); * @count: Number of bits to reset. * * Reset a consecutive range of bits in an HBitmap. + * @start and @count must be aligned to bitmap granularity. The only exc= eption + * is resetting the tail of the bitmap: @count may be equal to hb->orig_= size - + * @start, in this case @count may be not aligned. The sum of @start + @= count is + * allowed to be greater than hb->orig_size, but only if @start < hb->or= ig_size + * and @start + @count =3D ALIGN_UP(hb->orig_size, granularity). */ void hbitmap_reset(HBitmap *hb, uint64_t start, uint64_t count); =20 diff --git a/tests/test-hbitmap.c b/tests/test-hbitmap.c index eed5d288cbc..e1f867085f4 100644 --- a/tests/test-hbitmap.c +++ b/tests/test-hbitmap.c @@ -423,7 +423,7 @@ static void test_hbitmap_granularity(TestHBitmapData = *data, hbitmap_test_check(data, 0); hbitmap_test_set(data, 0, 3); g_assert_cmpint(hbitmap_count(data->hb), =3D=3D, 4); - hbitmap_test_reset(data, 0, 1); + hbitmap_test_reset(data, 0, 2); g_assert_cmpint(hbitmap_count(data->hb), =3D=3D, 2); } =20 diff --git a/util/hbitmap.c b/util/hbitmap.c index fd44c897ab0..757d39e360a 100644 --- a/util/hbitmap.c +++ b/util/hbitmap.c @@ -476,6 +476,10 @@ void hbitmap_reset(HBitmap *hb, uint64_t start, uint= 64_t count) /* Compute range in the last layer. */ uint64_t first; uint64_t last =3D start + count - 1; + uint64_t gran =3D 1ULL << hb->granularity; + + assert(!(start & (gran - 1))); + assert(!(count & (gran - 1)) || (start + count =3D=3D hb->orig_size)= ); =20 trace_hbitmap_reset(hb, start, count, start >> hb->granularity, last >> hb->granularit= y); --=20 2.21.0