From patchwork Thu Dec 20 16:23:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lars Ellenberg X-Patchwork-Id: 10739141 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 06BD3746 for ; Thu, 20 Dec 2018 16:35:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E8ED228E38 for ; Thu, 20 Dec 2018 16:35:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DBF91290EC; Thu, 20 Dec 2018 16:35:02 +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 vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 90E3828E38 for ; Thu, 20 Dec 2018 16:35:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733086AbeLTQek (ORCPT ); Thu, 20 Dec 2018 11:34:40 -0500 Received: from mail09.linbit.com ([212.69.161.110]:50104 "EHLO mail09.linbit.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730180AbeLTQej (ORCPT ); Thu, 20 Dec 2018 11:34:39 -0500 Received: from soda.linbit (212-186-191-219.static.upcbusiness.at [212.186.191.219]) by mail09.linbit.com (LINBIT Mail Daemon) with ESMTP id 6E7EB103B4DE; Thu, 20 Dec 2018 17:23:46 +0100 (CET) From: Lars Ellenberg To: Jens Axboe , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Cc: drbd-dev@lists.linbit.com Subject: [PATCH 05/17] drbd: disconnect, if the wrong UUIDs are attached on a connected peer Date: Thu, 20 Dec 2018 17:23:32 +0100 Message-Id: <20181220162344.8430-6-lars.ellenberg@linbit.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181220162344.8430-1-lars.ellenberg@linbit.com> References: <20181220162344.8430-1-lars.ellenberg@linbit.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP With "on-no-data-accessible suspend-io", DRBD requires the next attach or connect to be to the very same data generation uuid tag it lost last. If we first lost connection to the peer, then later lost connection to our own disk, we would usually refuse to re-connect to the peer, because it presents the wrong data set. However, if the peer first connects without a disk, and then attached its disk, we accepted that same wrong data set, which would be "unexpected" by any user of that DRBD and cause "undefined results" (read: very likely data corruption). The fix is to forcefully disconnect as soon as we notice that the peer attached to the "wrong" dataset. Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_receiver.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index fbf30fe45862..0a9f3c65f70a 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -4170,7 +4170,7 @@ static int receive_uuids(struct drbd_connection *connection, struct packet_info kfree(device->p_uuid); device->p_uuid = p_uuid; - if (device->state.conn < C_CONNECTED && + if ((device->state.conn < C_CONNECTED || device->state.pdsk == D_DISKLESS) && device->state.disk < D_INCONSISTENT && device->state.role == R_PRIMARY && (device->ed_uuid & ~((u64)1)) != (p_uuid[UI_CURRENT] & ~((u64)1))) {