From patchwork Fri Aug 9 16:13:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 11087275 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 9E4B213AC for ; Fri, 9 Aug 2019 16:30:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8A695202A5 for ; Fri, 9 Aug 2019 16:30:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7F118202DB; Fri, 9 Aug 2019 16:30:00 +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 2D193202A5 for ; Fri, 9 Aug 2019 16:30:00 +0000 (UTC) Received: from localhost ([::1]:32862 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hw7mB-0003SE-Do for patchwork-qemu-devel@patchwork.kernel.org; Fri, 09 Aug 2019 12:29:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57656) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hw7YE-0003yh-IG for qemu-devel@nongnu.org; Fri, 09 Aug 2019 12:15:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hw7YC-0004eZ-LA for qemu-devel@nongnu.org; Fri, 09 Aug 2019 12:15:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51518) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hw7Y9-0004cd-LU; Fri, 09 Aug 2019 12:15:29 -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 EA5367EBC4; Fri, 9 Aug 2019 16:15:28 +0000 (UTC) Received: from localhost (unknown [10.40.205.179]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 858895D9D3; Fri, 9 Aug 2019 16:15:28 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Fri, 9 Aug 2019 18:13:58 +0200 Message-Id: <20190809161407.11920-34-mreitz@redhat.com> In-Reply-To: <20190809161407.11920-1-mreitz@redhat.com> References: <20190809161407.11920-1-mreitz@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 [10.5.110.27]); Fri, 09 Aug 2019 16:15:28 +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] [PATCH v6 33/42] blockdev: Fix active commit choice 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP We have to perform an active commit whenever the top node has a parent that has taken the WRITE permission on it. Signed-off-by: Max Reitz Reviewed-by: Vladimir Sementsov-Ogievskiy --- blockdev.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/blockdev.c b/blockdev.c index ee8b951154..4e72f6f701 100644 --- a/blockdev.c +++ b/blockdev.c @@ -3356,6 +3356,7 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device, */ BlockdevOnError on_error = BLOCKDEV_ON_ERROR_REPORT; int job_flags = JOB_DEFAULT; + uint64_t top_perm, top_shared; if (!has_speed) { speed = 0; @@ -3468,14 +3469,31 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device, goto out; } - if (top_bs == bs) { + /* + * Active commit is required if and only if someone has taken a + * WRITE permission on the top node. Historically, we have always + * used active commit for top nodes, so continue that practice. + * (Active commit is never really wrong.) + */ + bdrv_get_cumulative_perm(top_bs, &top_perm, &top_shared); + if (top_perm & BLK_PERM_WRITE || + bdrv_skip_rw_filters(top_bs) == bdrv_skip_rw_filters(bs)) + { if (has_backing_file) { error_setg(errp, "'backing-file' specified," " but 'top' is the active layer"); goto out; } - commit_active_start(has_job_id ? job_id : NULL, bs, base_bs, - job_flags, speed, on_error, + if (!has_job_id) { + /* + * Emulate here what block_job_create() does, because it + * is possible that @bs != @top_bs (the block job should + * be named after @bs, even if @top_bs is the actual + * source) + */ + job_id = bdrv_get_device_name(bs); + } + commit_active_start(job_id, top_bs, base_bs, job_flags, speed, on_error, filter_node_name, NULL, NULL, false, &local_err); } else { BlockDriverState *overlay_bs = bdrv_find_overlay(bs, top_bs);