From nobody Sun May 5 13:04:52 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; 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 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1565016991; cv=none; d=zoho.com; s=zohoarc; b=k9VEVOiHiDqhsJtX6lr9UTvmLR7sGte/+aS9bF89c6gwDK8Q46GIlqq9Mp8jFDiVjMkTZiw1tJnrOCLNj8f356s4I9VfuIanE2zsJinZ8ft/kGQp2A/LFka3c2KVyBebwmshjB3zxgtQpRpcKLt1tdlC3R8/4n254OyU0/vFZAI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1565016991; h=Content-Transfer-Encoding:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:To:ARC-Authentication-Results; bh=X79hUdD4qy518PjcCmskSBWPM8HTyqRnoyeBXUe9vYY=; b=bNL1crJHvLQOYqC91CEar1Tp0NNrB/0+6UQ5L6E86NXxsJ2BBc6HTszZcQ+nqj2sU1cCsYI7wRTESHjQ5mZjJoBFWcsVXrdmtEMdTHFzu2XZApXEwquYCqD4m9NGzYhtlrIP6Xu3dQQApBnbJDIiHmFNzyMoJaZsDqdeAQm1AEo= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (209.51.188.17 [209.51.188.17]) by mx.zohomail.com with SMTPS id 1565016991995587.8871866201172; Mon, 5 Aug 2019 07:56:31 -0700 (PDT) Received: from localhost ([::1]:54596 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1huePP-0003Pz-8O for importer@patchew.org; Mon, 05 Aug 2019 10:56:23 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41712) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hueOx-0002ru-Gz for qemu-devel@nongnu.org; Mon, 05 Aug 2019 10:55:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hueOv-0003u7-Ih for qemu-devel@nongnu.org; Mon, 05 Aug 2019 10:55:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43636) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hueOs-0003ru-3x; Mon, 05 Aug 2019 10:55:50 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DE6D930833B0; Mon, 5 Aug 2019 14:55:48 +0000 (UTC) Received: from localhost (unknown [10.40.205.217]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AE8FE60CCE; Mon, 5 Aug 2019 14:55:43 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Mon, 5 Aug 2019 16:55:41 +0200 Message-Id: <20190805145541.3731-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Mon, 05 Aug 2019 14:55:49 +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 v2] 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" 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 --- v2: Fix the placement of our bdrv_refresh_limits() call [Vladimir] --- block/mirror.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/block/mirror.c b/block/mirror.c index 8cb75fb409..7f0ff01beb 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1481,6 +1481,15 @@ static void bdrv_mirror_top_child_perm(BlockDriverSt= ate *bs, BdrvChild *c, *nshared =3D BLK_PERM_ALL; } =20 +static void bdrv_mirror_top_refresh_limits(BlockDriverState *bs, Error **e= rrp) +{ + MirrorBDSOpaque *s =3D bs->opaque; + + if (s && s->job && s->job->copy_mode =3D=3D MIRROR_COPY_MODE_WRITE_BLO= CKING) { + bs->bl.request_alignment =3D s->job->granularity; + } +} + /* Dummy node that provides consistent read to its users without requiring= it * from its backing file and that allows writes on the backing file chain.= */ 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 +1647,21 @@ 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, &error_abort); + s->dirty_bitmap =3D bdrv_create_dirty_bitmap(bs, granularity, NULL, er= rp); if (!s->dirty_bitmap) { goto fail; --=20 2.21.0