From nobody Wed Dec 17 21:46:24 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.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 Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1631729498489866.9460157330357; Wed, 15 Sep 2021 11:11:38 -0700 (PDT) Received: from localhost ([::1]:37070 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mQZNh-00068D-CO for importer@patchew.org; Wed, 15 Sep 2021 14:11:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51968) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mQZ6f-0006UE-Mu for qemu-devel@nongnu.org; Wed, 15 Sep 2021 13:54:01 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:22260) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mQZ6e-0006tA-3h for qemu-devel@nongnu.org; Wed, 15 Sep 2021 13:54:01 -0400 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-393-axuihbpCOn6TQjxSnznaKg-1; Wed, 15 Sep 2021 13:53:58 -0400 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 EB2021966320; Wed, 15 Sep 2021 17:53:56 +0000 (UTC) Received: from localhost (unknown [10.39.192.101]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9498F7771A; Wed, 15 Sep 2021 17:53:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631728439; 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=JJLyditKkv+WSfGTBJalfCfVjtKWxjAtVBFYv2pOuv0=; b=I36BH/XY8GrFHzKz27WoJ1vgONMtWED+/fqFVNxvVQdhI+KN+IazEEr7KEGbUapZSvSAFk mr7u6kZmhhxuaqvS93GMCWCRl+6FKG9nUzAHhQZaJgzcKu7oOQeHj6PDdO/c5QJ8LnXs6b Q3auXBcwaV6PUtophvZMLOVCKAHWhhI= X-MC-Unique: axuihbpCOn6TQjxSnznaKg-1 From: Hanna Reitz To: qemu-block@nongnu.org Subject: [PULL 17/32] block: bdrv_inactivate_recurse(): check for permissions and fix crash Date: Wed, 15 Sep 2021 19:53:03 +0200 Message-Id: <20210915175318.853225-18-hreitz@redhat.com> In-Reply-To: <20210915175318.853225-1-hreitz@redhat.com> References: <20210915175318.853225-1-hreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=hreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.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; Received-SPF: pass client-ip=216.205.24.124; envelope-from=hreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.39, 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_H2=-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: Kevin Wolf , Peter Maydell , Hanna Reitz , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1631729500650100003 Content-Type: text/plain; charset="utf-8" From: Vladimir Sementsov-Ogievskiy We must not inactivate child when parent has write permissions on it. Calling .bdrv_inactivate() doesn't help: actually only qcow2 has this handler and it is used to flush caches, not for permission manipulations. So, let's simply check cumulative parent permissions before inactivating the node. This commit fixes a crash when we do migration during backup: prior to the commit nothing prevents all nodes inactivation at migration finish and following backup write to the target crashes on assertion "assert(!(bs->open_flags & BDRV_O_INACTIVE));" in bdrv_co_write_req_prepare(). After the commit, we rely on the fact that copy-before-write filter keeps write permission on target node to be able to write to it. So inactivation fails and migration fails as expected. Corresponding test now passes, so, enable it. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Hanna Reitz Message-Id: <20210911120027.8063-3-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz --- block.c | 8 ++++++++ tests/qemu-iotests/tests/migrate-during-backup | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/block.c b/block.c index 00982edf45..5ce08a79fd 100644 --- a/block.c +++ b/block.c @@ -6326,6 +6326,7 @@ static int bdrv_inactivate_recurse(BlockDriverState *= bs) { BdrvChild *child, *parent; int ret; + uint64_t cumulative_perms, cumulative_shared_perms; =20 if (!bs->drv) { return -ENOMEDIUM; @@ -6356,6 +6357,13 @@ static int bdrv_inactivate_recurse(BlockDriverState = *bs) } } =20 + bdrv_get_cumulative_perm(bs, &cumulative_perms, + &cumulative_shared_perms); + if (cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) { + /* Our inactive parents still need write access. Inactivation fail= ed. */ + return -EPERM; + } + bs->open_flags |=3D BDRV_O_INACTIVE; =20 /* diff --git a/tests/qemu-iotests/tests/migrate-during-backup b/tests/qemu-io= tests/tests/migrate-during-backup index 1046904c5a..34103229ee 100755 --- a/tests/qemu-iotests/tests/migrate-during-backup +++ b/tests/qemu-iotests/tests/migrate-during-backup @@ -1,5 +1,5 @@ #!/usr/bin/env python3 -# group: migration disabled +# group: migration # # Copyright (c) 2021 Virtuozzo International GmbH # --=20 2.31.1