From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1F00C43603 for ; Wed, 4 Dec 2019 18:17:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95EDA206DF for ; Wed, 4 Dec 2019 18:17:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575483436; bh=tDid7wWhwSEwo+cSH6ZJlxwNTRky9xCPIrL50w6xETA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=evDztWCB6gMT8otptSezo7MlGZ1ohTPjmgbcHTxiwdHt/FmP7cSM6qWjwziKQ+m0y 3YOEOvsWu/LY9iidZG0iOoObEveMbFzoW0MSP4I8RK5Ox9AYdCfeO0F00zGuz7l6l9 Cq3DXSo9fb/RcKB1ykyuAuw7KmU0ev0WmwQ6AjyQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732011AbfLDSRP (ORCPT ); Wed, 4 Dec 2019 13:17:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:40868 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731569AbfLDSMT (ORCPT ); Wed, 4 Dec 2019 13:12:19 -0500 Received: from localhost (unknown [217.68.49.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3FBF920865; Wed, 4 Dec 2019 18:12:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575483137; bh=tDid7wWhwSEwo+cSH6ZJlxwNTRky9xCPIrL50w6xETA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q2rFIcknFZCNFjqNdGw17FSeU+fqoENBwegTBAnMAHA0P8VdBg3/iSEUFx9Hl5OtY 4+5dpn+jqWbPzcKZfGd9aO/RE4C7gv0GeLDtDzCze9sYMKD/5lmdNxeeMczdO2oa1L R6KuWjrN1bROTO56pxt1haikCrz5WVwnPzvwNE7U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars Ellenberg , Jens Axboe , Sasha Levin Subject: [PATCH 4.9 066/125] drbd: reject attach of unsuitable uuids even if connected Date: Wed, 4 Dec 2019 18:56:11 +0100 Message-Id: <20191204175322.984130757@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191204175308.377746305@linuxfoundation.org> References: <20191204175308.377746305@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lars Ellenberg [ Upstream commit fe43ed97bba3b11521abd934b83ed93143470e4f ] Multiple failure scenario: a) all good Connected Primary/Secondary UpToDate/UpToDate b) lose disk on Primary, Connected Primary/Secondary Diskless/UpToDate c) continue to write to the device, changes only make it to the Secondary storage. d) lose disk on Secondary, Connected Primary/Secondary Diskless/Diskless e) now try to re-attach on Primary This would have succeeded before, even though that is clearly the wrong data set to attach to (missing the modifications from c). Because we only compared our "effective" and the "to-be-attached" data generation uuid tags if (device->state.conn < C_CONNECTED). Fix: change that constraint to (device->state.pdsk != D_UP_TO_DATE) compare the uuids, and reject the attach. This patch also tries to improve the reverse scenario: first lose Secondary, then Primary disk, then try to attach the disk on Secondary. Before this patch, the attach on the Secondary succeeds, but since commit drbd: disconnect, if the wrong UUIDs are attached on a connected peer the Primary will notice unsuitable data, and drop the connection hard. Though unfortunately at a point in time during the handshake where we cannot easily abort the attach on the peer without more refactoring of the handshake. We now reject any attach to "unsuitable" uuids, as long as we can see a Primary role, unless we already have access to "good" data. Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/drbd/drbd_nl.c | 6 +++--- drivers/block/drbd/drbd_receiver.c | 19 +++++++++++++++++++ 2 files changed, 22 insertions(+), 3 deletions(-) diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index abee91940a36d..ff26f676f24d1 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -1927,9 +1927,9 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info) } } - if (device->state.conn < C_CONNECTED && - device->state.role == R_PRIMARY && device->ed_uuid && - (device->ed_uuid & ~((u64)1)) != (nbc->md.uuid[UI_CURRENT] & ~((u64)1))) { + if (device->state.pdsk != D_UP_TO_DATE && device->ed_uuid && + (device->state.role == R_PRIMARY || device->state.peer == R_PRIMARY) && + (device->ed_uuid & ~((u64)1)) != (nbc->md.uuid[UI_CURRENT] & ~((u64)1))) { drbd_err(device, "Can only attach to data with current UUID=%016llX\n", (unsigned long long)device->ed_uuid); retcode = ERR_DATA_NOT_CURRENT; diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index bbd50d7dce43d..a10ff6e8c20b7 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -4452,6 +4452,25 @@ static int receive_state(struct drbd_connection *connection, struct packet_info if (peer_state.conn == C_AHEAD) ns.conn = C_BEHIND; + /* TODO: + * if (primary and diskless and peer uuid != effective uuid) + * abort attach on peer; + * + * If this node does not have good data, was already connected, but + * the peer did a late attach only now, trying to "negotiate" with me, + * AND I am currently Primary, possibly frozen, with some specific + * "effective" uuid, this should never be reached, really, because + * we first send the uuids, then the current state. + * + * In this scenario, we already dropped the connection hard + * when we received the unsuitable uuids (receive_uuids(). + * + * Should we want to change this, that is: not drop the connection in + * receive_uuids() already, then we would need to add a branch here + * that aborts the attach of "unsuitable uuids" on the peer in case + * this node is currently Diskless Primary. + */ + if (device->p_uuid && peer_state.disk >= D_NEGOTIATING && get_ldev_if_state(device, D_NEGOTIATING)) { int cr; /* consider resync */ -- 2.20.1