From patchwork Mon Nov 5 16:37:25 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 10668785 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 4A5A114BD for ; Mon, 5 Nov 2018 17:15:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 252702950A for ; Mon, 5 Nov 2018 17:15:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1932D298D4; Mon, 5 Nov 2018 17:15:57 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A8FDF2950A for ; Mon, 5 Nov 2018 17:15:56 +0000 (UTC) Received: from localhost ([::1]:36461 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gJiTj-0002QK-Nr for patchwork-qemu-devel@patchwork.kernel.org; Mon, 05 Nov 2018 12:15:55 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53933) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gJhzy-0000gM-DS for qemu-devel@nongnu.org; Mon, 05 Nov 2018 11:45:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gJhzx-000215-Nf for qemu-devel@nongnu.org; Mon, 05 Nov 2018 11:45:10 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36590) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gJhuz-0004TQ-St; Mon, 05 Nov 2018 11:40:02 -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 mx1.redhat.com (Postfix) with ESMTPS id 7B8083091751; Mon, 5 Nov 2018 16:38:44 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-117-198.ams2.redhat.com [10.36.117.198]) by smtp.corp.redhat.com (Postfix) with ESMTP id D73F265F56; Mon, 5 Nov 2018 16:38:42 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Mon, 5 Nov 2018 17:37:25 +0100 Message-Id: <20181105163744.25139-18-kwolf@redhat.com> In-Reply-To: <20181105163744.25139-1-kwolf@redhat.com> References: <20181105163744.25139-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Mon, 05 Nov 2018 16:38:44 +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 17/36] quorum: Forbid adding children in blkverify mode X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, 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: Alberto Garcia The blkverify mode of Quorum only works when the number of children is exactly two, so any attempt to add a new one must return an error. quorum_del_child() on the other hand doesn't need any additional check because decreasing the number of children would make it go under the vote threshold. Signed-off-by: Alberto Garcia Reported-by: Kevin Wolf Signed-off-by: Kevin Wolf --- block/quorum.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/block/quorum.c b/block/quorum.c index 6188ff6666..16b3c8067c 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -992,6 +992,11 @@ static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs, char indexstr[32]; int ret; + if (s->is_blkverify) { + error_setg(errp, "Cannot add a child to a quorum in blkverify mode"); + return; + } + assert(s->num_children <= INT_MAX / sizeof(BdrvChild *)); if (s->num_children == INT_MAX / sizeof(BdrvChild *) || s->next_child_index == UINT_MAX) { @@ -1046,6 +1051,9 @@ static void quorum_del_child(BlockDriverState *bs, BdrvChild *child, return; } + /* We know now that num_children > threshold, so blkverify must be false */ + assert(!s->is_blkverify); + bdrv_drained_begin(bs); /* We can safely remove this child now */