From patchwork Fri Aug 16 09:34:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 11097415 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C88CE1398 for ; Fri, 16 Aug 2019 09:43:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A7FCD2877E for ; Fri, 16 Aug 2019 09:43:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9873B289DC; Fri, 16 Aug 2019 09:43:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 451862877E for ; Fri, 16 Aug 2019 09:43:20 +0000 (UTC) Received: from localhost ([::1]:52554 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hyYlS-0000gn-Sl for patchwork-qemu-devel@patchwork.kernel.org; Fri, 16 Aug 2019 05:43:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59492) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hyYdL-0008LU-PI for qemu-devel@nongnu.org; Fri, 16 Aug 2019 05:34:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hyYdK-0003cC-MO for qemu-devel@nongnu.org; Fri, 16 Aug 2019 05:34:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12048) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hyYdI-0003Yy-1z; Fri, 16 Aug 2019 05:34:52 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 6266630842A9; Fri, 16 Aug 2019 09:34:51 +0000 (UTC) Received: from localhost.localdomain.com (dhcp-200-226.str.redhat.com [10.33.200.226]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9DE4A5C1B2; Fri, 16 Aug 2019 09:34:50 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 16 Aug 2019 11:34:30 +0200 Message-Id: <20190816093439.14262-8-kwolf@redhat.com> In-Reply-To: <20190816093439.14262-1-kwolf@redhat.com> References: <20190816093439.14262-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Fri, 16 Aug 2019 09:34:51 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 07/16] block: Keep subtree drained in drop_intermediate 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, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Max Reitz bdrv_drop_intermediate() calls BdrvChildRole.update_filename(). That may poll, thus changing the graph, which potentially breaks the QLIST_FOREACH_SAFE() loop. Just keep the whole subtree drained. This is probably the right thing to do anyway (dropping nodes while the subtree is not drained seems wrong). Signed-off-by: Max Reitz Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- block.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block.c b/block.c index 6db8ecd62b..df3407934b 100644 --- a/block.c +++ b/block.c @@ -4491,6 +4491,7 @@ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, int ret = -EIO; bdrv_ref(top); + bdrv_subtree_drained_begin(top); if (!top->drv || !base->drv) { goto exit; @@ -4562,6 +4563,7 @@ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, ret = 0; exit: + bdrv_subtree_drained_end(top); bdrv_unref(top); return ret; }