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 3A28CC433FF for ; Tue, 6 Aug 2019 12:01:05 +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 149FB20B1F for ; Tue, 6 Aug 2019 12:01:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 149FB20B1F 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]:60616 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1huy9I-0002M3-8x for qemu-devel@archiver.kernel.org; Tue, 06 Aug 2019 08:01:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60067) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1huy8G-0000V2-Ro for qemu-devel@nongnu.org; Tue, 06 Aug 2019 08:00:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1huy8F-0001dS-SL for qemu-devel@nongnu.org; Tue, 06 Aug 2019 08:00:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46278) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1huy8D-0001bY-Ph; Tue, 06 Aug 2019 07:59:57 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1A66D85539; Tue, 6 Aug 2019 11:59:57 +0000 (UTC) Received: from localhost (ovpn-204-49.brq.redhat.com [10.40.204.49]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A56895D704; Tue, 6 Aug 2019 11:59:56 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Tue, 6 Aug 2019 13:59:46 +0200 Message-Id: <20190806115952.8456-2-mreitz@redhat.com> In-Reply-To: <20190806115952.8456-1-mreitz@redhat.com> References: <20190806115952.8456-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Tue, 06 Aug 2019 11:59:57 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL v2 1/7] backup: Copy only dirty areas 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: Kevin Wolf , Peter Maydell , qemu-stable@nongnu.org, qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The backup job must only copy areas that the copy_bitmap reports as dirty. This is always the case when using traditional non-offloading backup, because it copies each cluster separately. When offloading the copy operation, we sometimes copy more than one cluster at a time, but we only check whether the first one is dirty. Therefore, whenever copy offloading is possible, the backup job currently produces wrong output when the guest writes to an area of which an inner part has already been backed up, because that inner part will be re-copied. Fixes: 9ded4a0114968e98b41494fc035ba14f84cdf700 Signed-off-by: Max Reitz Reviewed-by: Vladimir Sementsov-Ogievskiy Message-id: 20190801173900.23851-2-mreitz@redhat.com Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz --- block/backup.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/block/backup.c b/block/backup.c index 715e1d3be8..1ee271f9f1 100644 --- a/block/backup.c +++ b/block/backup.c @@ -202,22 +202,31 @@ static int coroutine_fn backup_do_cow(BackupBlockJo= b *job, cow_request_begin(&cow_request, job, start, end); =20 while (start < end) { + int64_t dirty_end; + if (!hbitmap_get(job->copy_bitmap, start)) { trace_backup_do_cow_skip(job, start); start +=3D job->cluster_size; continue; /* already copied */ } =20 + dirty_end =3D hbitmap_next_zero(job->copy_bitmap, start, (end - = start)); + if (dirty_end < 0) { + dirty_end =3D end; + } + trace_backup_do_cow_process(job, start); =20 if (job->use_copy_range) { - ret =3D backup_cow_with_offload(job, start, end, is_write_no= tifier); + ret =3D backup_cow_with_offload(job, start, dirty_end, + is_write_notifier); if (ret < 0) { job->use_copy_range =3D false; } } if (!job->use_copy_range) { - ret =3D backup_cow_with_bounce_buffer(job, start, end, is_wr= ite_notifier, + ret =3D backup_cow_with_bounce_buffer(job, start, dirty_end, + is_write_notifier, error_is_read, &bounce_b= uffer); } if (ret < 0) { --=20 2.21.0