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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 2EC60C433E0 for ; Thu, 6 Aug 2020 15:49:19 +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 5674922EBD for ; Thu, 6 Aug 2020 15:49:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VN9zJpgw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5674922EBD 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]:59950 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k3i8s-0004rw-7C for qemu-devel@archiver.kernel.org; Thu, 06 Aug 2020 11:49:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57012) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k3i7K-0003Az-07 for qemu-devel@nongnu.org; Thu, 06 Aug 2020 11:47:43 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:59614 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1k3i7F-0006NL-76 for qemu-devel@nongnu.org; Thu, 06 Aug 2020 11:47:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596728855; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QipeNrVWJzDJea/AY5cowmlgrgFOBzE967YBpguCRec=; b=VN9zJpgwtOkHIj7wgDILsckvKvu8wW20jX5KlhTPhP+Boz13V09zN5Ahf5OGNnS6v60YlS Ea8ej+MhPHYzBKp/euVzPt2XRZfSoprR3T/r0JQ/N2o5MRIgunTK2ZsYOQc4V2DquZzUux tiblBVCg1P06t/J8olp/tUujPVtVwYg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-2-xJxiXtb4O7OuyECW9-krrA-1; Thu, 06 Aug 2020 11:47:28 -0400 X-MC-Unique: xJxiXtb4O7OuyECW9-krrA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 317F780048D; Thu, 6 Aug 2020 15:47:26 +0000 (UTC) Received: from [10.3.115.21] (ovpn-115-21.phx2.redhat.com [10.3.115.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 383438AC08; Thu, 6 Aug 2020 15:47:24 +0000 (UTC) Subject: Re: [PATCH for-5.1?] block/block-copy: always align copied region to cluster size To: Stefan Reiter , qemu-block@nongnu.org References: <20200806135740.24420-1-s.reiter@proxmox.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <987a7881-bc89-72d9-7b9b-2383c2e6aa8e@redhat.com> Date: Thu, 6 Aug 2020 10:47:24 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200806135740.24420-1-s.reiter@proxmox.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=205.139.110.120; envelope-from=eblake@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/06 00:24:10 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: kwolf@redhat.com, vsementsov@virtuozzo.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 8/6/20 8:57 AM, Stefan Reiter wrote: > Since commit 42ac214406e0 (block/block-copy: refactor task creation) > block_copy_task_create calculates the area to be copied via > bdrv_dirty_bitmap_next_dirty_area, but that can return an unaligned byte > count if the backing image's last cluster end is not aligned to the > bitmap's granularity. > > Always ALIGN_UP the resulting bytes value to satisfy block_copy_do_copy, > which requires the 'bytes' parameter to be aligned to cluster size. > > Signed-off-by: Stefan Reiter > --- As this is an assertion failure in a feature new to 5.1, this might be a candidate for inclusion if we have other reasons to go with -rc4. But it's awfully late, I don't think this bug is sufficient on its own to delay the release. > > This causes backups with unaligned image sizes to fail on the last block in my > testing (e.g. a backup job with 4k cluster size fails on a drive with 4097 > bytes). > > Alternatively one could remove the > assert(QEMU_IS_ALIGNED(bytes, s->cluster_size)); > from block_copy_do_copy, but I'd wager that's there for a reason? > > block/block-copy.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/block/block-copy.c b/block/block-copy.c > index f7428a7c08..023cb03200 100644 > --- a/block/block-copy.c > +++ b/block/block-copy.c > @@ -142,6 +142,8 @@ static BlockCopyTask *block_copy_task_create(BlockCopyState *s, > return NULL; > } > > + bytes = QEMU_ALIGN_UP(bytes, s->cluster_size); > + > /* region is dirty, so no existent tasks possible in it */ > assert(!find_conflicting_task(s, offset, bytes)); > > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org