From patchwork Tue Feb 18 10:34:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 1239930 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=JscX5uoJ; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 48MHSm4dtWz9sRf for ; Tue, 18 Feb 2020 21:40:56 +1100 (AEDT) Received: from localhost ([::1]:60648 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j40JC-0004Br-Gu for incoming@patchwork.ozlabs.org; Tue, 18 Feb 2020 05:40:54 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52219) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j40Dy-0001o3-Bf for qemu-devel@nongnu.org; Tue, 18 Feb 2020 05:35:31 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j40Dx-0007TS-5m for qemu-devel@nongnu.org; Tue, 18 Feb 2020 05:35:30 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:44325 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j40Dx-0007TK-1e for qemu-devel@nongnu.org; Tue, 18 Feb 2020 05:35:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582022128; 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=wrJiiw5y0UxtoIosHElrm5q85GG0zS+pG2zOdvNiYJM=; b=JscX5uoJuAKfkGq3K2842QWoSZu+SLlQINememDVEZY4J7cDFlQtejgBfnWB3P2ZAXIFtl QRKp6MDk5KyXTgtS1ecmuwxui+jQ60/rJmDirvblguhQzV5bymjGa0Kskuo1PuwhN//y6I SzpHseXgsZ0pOAq/tBmDIP6E2vTi67o= 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-375-McHMmTziN6yKRI3RhE8RHw-1; Tue, 18 Feb 2020 05:35:25 -0500 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id EF966477; Tue, 18 Feb 2020 10:35:23 +0000 (UTC) Received: from localhost (unknown [10.36.118.17]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6AC2860BE1; Tue, 18 Feb 2020 10:35:23 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Subject: [PATCH v4 09/19] block: Use bdrv_recurse_can_replace() Date: Tue, 18 Feb 2020 11:34:44 +0100 Message-Id: <20200218103454.296704-10-mreitz@redhat.com> In-Reply-To: <20200218103454.296704-1-mreitz@redhat.com> References: <20200218103454.296704-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: McHMmTziN6yKRI3RhE8RHw-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Let check_to_replace_node() use the more specialized bdrv_recurse_can_replace() instead of bdrv_recurse_is_first_non_filter(), which is too restrictive (or, in the case of quorum, sometimes not restrictive enough). Signed-off-by: Max Reitz Reviewed-by: Vladimir Sementsov-Ogievskiy --- block.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/block.c b/block.c index 553ccff216..7efe8f3b03 100644 --- a/block.c +++ b/block.c @@ -6273,6 +6273,17 @@ bool bdrv_recurse_can_replace(BlockDriverState *bs, return false; } +/* + * Check whether the given @node_name can be replaced by a node that + * has the same data as @parent_bs. If so, return @node_name's BDS; + * NULL otherwise. + * + * @node_name must be a (recursive) *child of @parent_bs (or this + * function will return NULL). + * + * The result (whether the node can be replaced or not) is only valid + * for as long as no graph or permission changes occur. + */ BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, const char *node_name, Error **errp) { @@ -6297,8 +6308,11 @@ BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, * Another benefit is that this tests exclude backing files which are * blocked by the backing blockers. */ - if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) { - error_setg(errp, "Only top most non filter can be replaced"); + if (!bdrv_recurse_can_replace(parent_bs, to_replace_bs)) { + error_setg(errp, "Cannot replace '%s' by a node mirrored from '%s', " + "because it cannot be guaranteed that doing so would not " + "lead to an abrupt change of visible data", + node_name, parent_bs->node_name); to_replace_bs = NULL; goto out; }