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=ham 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 57500C43603 for ; Wed, 4 Dec 2019 18:21:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2BD092073C for ; Wed, 4 Dec 2019 18:21:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575483683; bh=6nw8p55LQxTrXbv68h7YR+Jq/74C7CEpUk0H1DdNjX0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YD9HD/vDEMOJZKmLZ//iyrxyYs6ddkECUacHbk2u9PUC8QE/+1r7d0V9aFokaT/dG FBnKF+HnVpxfwEiXay5JXwGJpXLI2kTqLqs5DkYAz+DruEjFnOTPiqwJhL9uBpUjBa jZPpZV8Ue+YLb/eAQYMFD2CKxEPQNSkapLWTZ4so= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730641AbfLDSGy (ORCPT ); Wed, 4 Dec 2019 13:06:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:55766 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728490AbfLDSGv (ORCPT ); Wed, 4 Dec 2019 13:06:51 -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 C604E206DF; Wed, 4 Dec 2019 18:06:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575482810; bh=6nw8p55LQxTrXbv68h7YR+Jq/74C7CEpUk0H1DdNjX0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lNcL4r7RMPXErkAAJ1cB5s8ekT/Xo7k7SlxSD01eYFCm/MkMM2yjRyvMxkl5x4WrT DzN9AaDj3jr7iQIlxVpWL16HWEqWzuM73xLyLBl7GMiZVGwt4gCr2i2q5AddbwFk/i laq9ww2qWRAb9HzZeNeLdyY4I7hYU3Wze5CxBRlM= 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 4.14 099/209] drbd: ignore "all zero" peer volume sizes in handshake Date: Wed, 4 Dec 2019 18:55:11 +0100 Message-Id: <20191204175328.678898763@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191204175321.609072813@linuxfoundation.org> References: <20191204175321.609072813@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 94c43a13b8d6e3e0dd77b3536b5e04a84936b762 ] During handshake, if we are diskless ourselves, we used to accept any size presented by the peer. Which could be zero if that peer was just brought up and connected to us without having a disk attached first, in which case both peers would just "flip" their volume sizes. Now, even a diskless node will ignore "zero" sizes presented by a diskless peer. Also a currently Diskless Primary will refuse to shrink during handshake: it may be frozen, and waiting for a "suitable" local disk or peer to re-appear (on-no-data-accessible suspend-io). If the peer is smaller than what we used to be, it is not suitable. The logic for a diskless node during handshake is now supposed to be: believe the peer, if - I don't have a current size myself - we agree on the size anyways - I do have a current size, am Secondary, and he has the only disk - I do have a current size, am Primary, and he has the only disk, which is larger than my current size Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/drbd/drbd_receiver.c | 33 +++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 8fbdfaacc2226..08586bc5219bf 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -3977,6 +3977,7 @@ static int receive_sizes(struct drbd_connection *connection, struct packet_info struct o_qlim *o = (connection->agreed_features & DRBD_FF_WSAME) ? p->qlim : NULL; enum determine_dev_size dd = DS_UNCHANGED; sector_t p_size, p_usize, p_csize, my_usize; + sector_t new_size, cur_size; int ldsc = 0; /* local disk size changed */ enum dds_flags ddsf; @@ -3984,6 +3985,7 @@ static int receive_sizes(struct drbd_connection *connection, struct packet_info if (!peer_device) return config_unknown_volume(connection, pi); device = peer_device->device; + cur_size = drbd_get_capacity(device->this_bdev); p_size = be64_to_cpu(p->d_size); p_usize = be64_to_cpu(p->u_size); @@ -3994,7 +3996,6 @@ static int receive_sizes(struct drbd_connection *connection, struct packet_info device->p_size = p_size; if (get_ldev(device)) { - sector_t new_size, cur_size; rcu_read_lock(); my_usize = rcu_dereference(device->ldev->disk_conf)->disk_size; rcu_read_unlock(); @@ -4012,7 +4013,6 @@ static int receive_sizes(struct drbd_connection *connection, struct packet_info /* Never shrink a device with usable data during connect. But allow online shrinking if we are connected. */ new_size = drbd_new_dev_size(device, device->ldev, p_usize, 0); - cur_size = drbd_get_capacity(device->this_bdev); if (new_size < cur_size && device->state.disk >= D_OUTDATED && device->state.conn < C_CONNECTED) { @@ -4077,9 +4077,36 @@ static int receive_sizes(struct drbd_connection *connection, struct packet_info * * However, if he sends a zero current size, * take his (user-capped or) backing disk size anyways. + * + * Unless of course he does not have a disk himself. + * In which case we ignore this completely. */ + sector_t new_size = p_csize ?: p_usize ?: p_size; drbd_reconsider_queue_parameters(device, NULL, o); - drbd_set_my_capacity(device, p_csize ?: p_usize ?: p_size); + if (new_size == 0) { + /* Ignore, peer does not know nothing. */ + } else if (new_size == cur_size) { + /* nothing to do */ + } else if (cur_size != 0 && p_size == 0) { + drbd_warn(device, "Ignored diskless peer device size (peer:%llu != me:%llu sectors)!\n", + (unsigned long long)new_size, (unsigned long long)cur_size); + } else if (new_size < cur_size && device->state.role == R_PRIMARY) { + drbd_err(device, "The peer's device size is too small! (%llu < %llu sectors); demote me first!\n", + (unsigned long long)new_size, (unsigned long long)cur_size); + conn_request_state(peer_device->connection, NS(conn, C_DISCONNECTING), CS_HARD); + return -EIO; + } else { + /* I believe the peer, if + * - I don't have a current size myself + * - we agree on the size anyways + * - I do have a current size, am Secondary, + * and he has the only disk + * - I do have a current size, am Primary, + * and he has the only disk, + * which is larger than my current size + */ + drbd_set_my_capacity(device, new_size); + } } if (get_ldev(device)) { -- 2.20.1