From patchwork Thu Oct 17 21:54:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Snow X-Patchwork-Id: 11197225 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0516617E1 for ; Thu, 17 Oct 2019 22:03:20 +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 D9A8B21D7D for ; Thu, 17 Oct 2019 22:03:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D9A8B21D7D 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:60988 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iLDra-0007jI-DH for patchwork-qemu-devel@patchwork.kernel.org; Thu, 17 Oct 2019 18:03:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:32859) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iLDjo-0007DM-LX for qemu-devel@nongnu.org; Thu, 17 Oct 2019 17:55:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iLDjn-0002Wy-9d for qemu-devel@nongnu.org; Thu, 17 Oct 2019 17:55:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37872) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iLDjj-0002SU-JG; Thu, 17 Oct 2019 17:55:11 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id BDB01307D986; Thu, 17 Oct 2019 21:55:10 +0000 (UTC) Received: from probe.bos.redhat.com (dhcp-17-173.bos.redhat.com [10.18.17.173]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5E2EC5D9DC; Thu, 17 Oct 2019 21:55:09 +0000 (UTC) From: John Snow To: Peter Maydell , jsnow@redhat.com, qemu-devel@nongnu.org Subject: [PULL v3 10/19] block: reverse order for reopen commits Date: Thu, 17 Oct 2019 17:54:27 -0400 Message-Id: <20191017215436.14252-11-jsnow@redhat.com> In-Reply-To: <20191017215436.14252-1-jsnow@redhat.com> References: <20191017215436.14252-1-jsnow@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Thu, 17 Oct 2019 21:55:10 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 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: Fam Zheng , Kevin Wolf , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, Juan Quintela , libvir-list@redhat.com, Markus Armbruster , "Dr. David Alan Gilbert" , Max Reitz , Stefan Hajnoczi Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" From: Vladimir Sementsov-Ogievskiy It's needed to fix reopening qcow2 with bitmaps to RW. Currently it can't work, as qcow2 needs write access to file child, to mark bitmaps in-image with IN_USE flag. But usually children goes after parents in reopen queue and file child is still RO on qcow2 reopen commit. Reverse reopen order to fix it. Signed-off-by: Vladimir Sementsov-Ogievskiy Acked-by: Max Reitz Acked-by: John Snow Message-id: 20190927122355.7344-3-vsementsov@virtuozzo.com Signed-off-by: John Snow --- block.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/block.c b/block.c index 0347632c6c..cf312258a9 100644 --- a/block.c +++ b/block.c @@ -3486,10 +3486,16 @@ int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp) bs_entry->perms_checked = true; } - /* If we reach this point, we have success and just need to apply the - * changes + /* + * If we reach this point, we have success and just need to apply the + * changes. + * + * Reverse order is used to comfort qcow2 driver: on commit it need to write + * IN_USE flag to the image, to mark bitmaps in the image as invalid. But + * children are usually goes after parents in reopen-queue, so go from last + * to first element. */ - QTAILQ_FOREACH(bs_entry, bs_queue, entry) { + QTAILQ_FOREACH_REVERSE(bs_entry, bs_queue, entry) { bdrv_reopen_commit(&bs_entry->state); }