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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,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 F2250C433DB for ; Wed, 24 Feb 2021 15:52:02 +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 59F4464ED4 for ; Wed, 24 Feb 2021 15:52:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 59F4464ED4 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]:49648 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lEwSH-0002EK-8g for qemu-devel@archiver.kernel.org; Wed, 24 Feb 2021 10:52:01 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52402) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lEwQH-0000IX-41 for qemu-devel@nongnu.org; Wed, 24 Feb 2021 10:49:57 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:41135) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lEwQC-0007z9-NQ for qemu-devel@nongnu.org; Wed, 24 Feb 2021 10:49:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614181791; 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: in-reply-to:in-reply-to:references:references; bh=KfeOEZ1vWlZTt6deAF20ZwaU4GB9Ee+ARTFVXcflCIQ=; b=VPNYwe2L5Vk2DDH1WTbHTe4tIFL4gXFVPrl4kF4YGdepdZUiVrKhmt2to6JovpBnBLjke6 g3fUTR4KG+k9S/fg+NmcUVYO/ARoMJSZA7+PHiJ67VSDJ1tjuqbnIt+p73YUFx3XuDSh3D ojR103yiMia2yNSFSZCZsY4DGaYqSac= 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-60-88kCeTXtNh22X9l1pPlSbg-1; Wed, 24 Feb 2021 10:49:48 -0500 X-MC-Unique: 88kCeTXtNh22X9l1pPlSbg-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 742F61007300; Wed, 24 Feb 2021 15:33:04 +0000 (UTC) Received: from merkur.fritz.box (ovpn-114-142.ams2.redhat.com [10.36.114.142]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5015B19727; Wed, 24 Feb 2021 15:33:03 +0000 (UTC) Date: Wed, 24 Feb 2021 16:33:01 +0100 From: Kevin Wolf To: Max Reitz Subject: Re: [PATCH 1/3] backup: Remove nodes from job in .clean() Message-ID: <20210224153301.GD11025@merkur.fritz.box> References: <20210219153348.41861-1-mreitz@redhat.com> <20210219153348.41861-2-mreitz@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210219153348.41861-2-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: Vladimir Sementsov-Ogievskiy , John Snow , qemu-devel@nongnu.org, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 19.02.2021 um 16:33 hat Max Reitz geschrieben: > The block job holds a reference to the backup-top node (because it is > passed as the main job BDS to block_job_create()). Therefore, > bdrv_backup_top_drop() cannot delete the backup-top node (replacing it > by its child does not affect the job parent, because that has > .stay_at_node set). That is a problem, because all of its I/O functions > assume the BlockCopyState (s->bcs) to be valid and that it has a > filtered child; but after bdrv_backup_top_drop(), neither of those > things are true. This kind of suggests that block_copy_state_free() doesn't really belong in bdrv_backup_top_drop(), but in a .bdrv_close callback. Doesn't make this patch less correct, of course. We still want to have all references dropped at the end of bdrv_backup_top_drop(). > It does not make sense to add new parents to backup-top after > backup_clean(), so we should detach it from the job before > bdrv_backup_top_drop(). Because there is no function to do that for a > single node, just detach all of the job's nodes -- the job does not do > anything past backup_clean() anyway. > > Signed-off-by: Max Reitz Reviewed-by: Kevin Wolf