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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AEA50C433F5 for ; Thu, 4 Nov 2021 10:42:52 +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 6F0556120F for ; Thu, 4 Nov 2021 10:42:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6F0556120F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:40906 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1miaCp-0000sO-Go for qemu-devel@archiver.kernel.org; Thu, 04 Nov 2021 06:42:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56306) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mia9X-0003vd-BQ for qemu-devel@nongnu.org; Thu, 04 Nov 2021 06:39:27 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:26919) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mia9V-0006uA-4z for qemu-devel@nongnu.org; Thu, 04 Nov 2021 06:39:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1636022363; 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=z6668KD6YY0BeZYP8+rehG/6fOcNrcpgLGR5j1kl6c4=; b=Ld7pAPJJtXmLKn/vL2Yqe8bXJPdpADGa1InwbYxfqd6uU9nnWF++qy4wxSYfLEAOYMm+4U BjCye3NSCKxLS2PTqFOsM7Xr4veaXoIWzBOqjsG3WV89Sa74O5pAAbBXy8b3U3yG2iW0lC IrcpC22ufdYIcF0B+am68/r0vk0iEHA= 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-359-qxdYRPBIOFiFGYkzRGk6bg-1; Thu, 04 Nov 2021 06:39:20 -0400 X-MC-Unique: qxdYRPBIOFiFGYkzRGk6bg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A748218125C0; Thu, 4 Nov 2021 10:39:19 +0000 (UTC) Received: from localhost (unknown [10.39.192.248]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 804B5A6C5D; Thu, 4 Nov 2021 10:39:04 +0000 (UTC) From: Hanna Reitz To: qemu-block@nongnu.org Subject: [PATCH 1/7] stream: Traverse graph after modification Date: Thu, 4 Nov 2021 11:38:43 +0100 Message-Id: <20211104103849.46855-2-hreitz@redhat.com> In-Reply-To: <20211104103849.46855-1-hreitz@redhat.com> References: <20211104103849.46855-1-hreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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: 8bit Content-Type: text/plain; charset="US-ASCII" 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: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.717, 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=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Hanna Reitz , Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" bdrv_cor_filter_drop() modifies the block graph. That means that other parties can also modify the block graph before it returns. Therefore, we cannot assume that the result of a graph traversal we did before remains valid afterwards. We should thus fetch `base` and `unfiltered_base` afterwards instead of before. Signed-off-by: Hanna Reitz --- block/stream.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/block/stream.c b/block/stream.c index 97bee482dc..e45113aed6 100644 --- a/block/stream.c +++ b/block/stream.c @@ -54,8 +54,8 @@ static int stream_prepare(Job *job) { StreamBlockJob *s = container_of(job, StreamBlockJob, common.job); BlockDriverState *unfiltered_bs = bdrv_skip_filters(s->target_bs); - BlockDriverState *base = bdrv_filter_or_cow_bs(s->above_base); - BlockDriverState *unfiltered_base = bdrv_skip_filters(base); + BlockDriverState *base; + BlockDriverState *unfiltered_base; Error *local_err = NULL; int ret = 0; @@ -63,6 +63,9 @@ static int stream_prepare(Job *job) bdrv_cor_filter_drop(s->cor_filter_bs); s->cor_filter_bs = NULL; + base = bdrv_filter_or_cow_bs(s->above_base); + unfiltered_base = bdrv_skip_filters(base); + if (bdrv_cow_child(unfiltered_bs)) { const char *base_id = NULL, *base_fmt = NULL; if (unfiltered_base) { -- 2.33.1