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 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 39357C0650F for ; Mon, 5 Aug 2019 15:38:11 +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 0B93D216F4 for ; Mon, 5 Aug 2019 15:38:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0B93D216F4 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]:55048 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1huf3q-0006eO-Br for qemu-devel@archiver.kernel.org; Mon, 05 Aug 2019 11:38:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52748) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1huezA-0006ku-Us for qemu-devel@nongnu.org; Mon, 05 Aug 2019 11:33:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1huez9-0002MK-27 for qemu-devel@nongnu.org; Mon, 05 Aug 2019 11:33:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58608) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1huez3-0002Id-KX; Mon, 05 Aug 2019 11:33:13 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E21183090FEC; Mon, 5 Aug 2019 15:33:12 +0000 (UTC) Received: from localhost (unknown [10.40.205.217]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 28DFC5DA8B; Mon, 5 Aug 2019 15:33:09 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Mon, 5 Aug 2019 17:33:08 +0200 Message-Id: <20190805153308.2657-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.43]); Mon, 05 Aug 2019 15:33:12 +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] [PATCH v3] mirror: Only mirror granularity-aligned chunks 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 , Vladimir Sementsov-Ogievskiy , qemu-stable@nongnu.org, qemu-devel@nongnu.org, Max Reitz , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" In write-blocking mode, all writes to the top node directly go to the target. We must only mirror chunks of data that are aligned to the job's granularity, because that is how the dirty bitmap works. Therefore, the request alignment for writes must be the job's granularity (in write-blocking mode). Unfortunately, this forces all reads and writes to have the same granularity (we only need this alignment for writes to the target, not the source), but that is something to be fixed another time. Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz --- v3: Handle bdrv_refresh_limits() errors [Vladimir] --- block/mirror.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/block/mirror.c b/block/mirror.c index 8cb75fb409..9f5c59ece1 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1481,6 +1481,15 @@ static void bdrv_mirror_top_child_perm(BlockDriver= State *bs, BdrvChild *c, *nshared =3D BLK_PERM_ALL; } =20 +static void bdrv_mirror_top_refresh_limits(BlockDriverState *bs, Error *= *errp) +{ + MirrorBDSOpaque *s =3D bs->opaque; + + if (s && s->job && s->job->copy_mode =3D=3D MIRROR_COPY_MODE_WRITE_B= LOCKING) { + bs->bl.request_alignment =3D s->job->granularity; + } +} + /* Dummy node that provides consistent read to its users without requiri= ng it * from its backing file and that allows writes on the backing file chai= n. */ static BlockDriver bdrv_mirror_top =3D { @@ -1493,6 +1502,7 @@ static BlockDriver bdrv_mirror_top =3D { .bdrv_co_block_status =3D bdrv_co_block_status_from_backing, .bdrv_refresh_filename =3D bdrv_mirror_top_refresh_filename, .bdrv_child_perm =3D bdrv_mirror_top_child_perm, + .bdrv_refresh_limits =3D bdrv_mirror_top_refresh_limits, }; =20 static BlockJob *mirror_start_job( @@ -1637,6 +1647,25 @@ static BlockJob *mirror_start_job( s->should_complete =3D true; } =20 + /* + * Must be called before we start tracking writes, but after + * + * ((MirrorBlockJob *) + * ((MirrorBDSOpaque *) + * mirror_top_bs->opaque + * )->job + * )->copy_mode + * + * has the correct value. + * (We start tracking writes as of the following + * bdrv_create_dirty_bitmap() call.) + */ + bdrv_refresh_limits(mirror_top_bs, &local_err); + if (local_err) { + error_propagate(errp, local_err); + goto fail; + } + s->dirty_bitmap =3D bdrv_create_dirty_bitmap(bs, granularity, NULL, = errp); if (!s->dirty_bitmap) { goto fail; --=20 2.21.0