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=DATE_IN_FUTURE_06_12, DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 5DDBAC3A5A9 for ; Mon, 4 May 2020 10:58:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1BE2E2073B for ; Mon, 4 May 2020 10:58:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="lOZBMVaX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728007AbgEDK6w (ORCPT ); Mon, 4 May 2020 06:58:52 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:56932 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726445AbgEDK6v (ORCPT ); Mon, 4 May 2020 06:58:51 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 044Ar33x028466 for ; Mon, 4 May 2020 10:58:50 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=corp-2020-01-29; bh=7CLmkY3i7XgSstHJleXKux7AFn66VW1lMOfHAeRofps=; b=lOZBMVaXVXl9H7v1lwXvw0qYhijHeVSgP5KLMkBmtKDNcj52xUHu/uhgfPguwlANVQjt nXz30Guv51fMnRLiw+751eGqjo2b5uvO8PElbcx7mq9hi3cZMJT25Q50NCt/QSDUGcNn mkM/e/tGjONMkX9r2NBbHjahH3FGv3oOlEWdGqQW9RejqeYrh8GdvXD8Dam08iBQtI75 r+QZCymso5ZY6quZDfN0qfU/HUaUcEG8HtcOsyskqcJvSB0iaDRV/3dRZzthMMBw/0/m 4bXoCrGwtBHTBc3KOEvvioW2yd4eKY3zT+Jwh6XgxoSl8Nqrlz94vTQByP0XT1pG3wGM PQ== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2120.oracle.com with ESMTP id 30s0tm64nu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Mon, 04 May 2020 10:58:50 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 044AvbTp146466 for ; Mon, 4 May 2020 10:58:49 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3030.oracle.com with ESMTP id 30t1r1xcuq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Mon, 04 May 2020 10:58:49 +0000 Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 044AwmZ2006445 for ; Mon, 4 May 2020 10:58:48 GMT Received: from localhost.localdomain (/39.109.243.230) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 04 May 2020 03:58:48 -0700 From: Anand Jain To: linux-btrfs@vger.kernel.org Subject: [PATCH v4 2/3] btrfs: include non-missing as a qualifier for the latest_bdev Date: Tue, 5 May 2020 02:58:25 +0800 Message-Id: <20200504185826.9954-1-anand.jain@oracle.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200428152227.8331-4-anand.jain@oracle.com> References: <20200428152227.8331-4-anand.jain@oracle.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9610 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 adultscore=0 suspectscore=3 spamscore=0 mlxlogscore=999 malwarescore=0 phishscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005040094 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9610 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxscore=0 priorityscore=1501 lowpriorityscore=0 spamscore=0 suspectscore=3 phishscore=0 clxscore=1015 bulkscore=0 mlxlogscore=999 adultscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005040093 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org btrfs_free_extra_devids() reorgs fs_devices::latest_bdev to point to the bdev with greatest device::generation number. For a typical-missing device the generation number is zero so fs_devices::latest_bdev will never point to it. But if the missing device is due to alienation [1], then device::generation is not-zero and if it is >= to rest of device::generation in the list, then fs_devices::latest_bdev ends up pointing to the missing device and reports the error like this [2] [1] We maintain devices of a fsid (as in fs_device::fsid) in the fs_devices::devices list, a device is considered as an alien device if its fsid does not match with the fs_device::fsid Consider a working raid1. $ mkfs.btrfs -fq -draid1 -mraid1 /dev/sdb /dev/sdc $ mount /dev/sdb /btrfs $ umount /btrfs While raid1 was unmounted the user decides to force add one its device to another btrfs fs. $ mkfs.btrfs -fq /dev/sdd $ mount /dev/sdd /btrfs1 $ btrfs dev add -f /dev/sdb /btrfs1 Now the original raid1 fails to mount in degraded, because fs_devices::latest_bdev is pointing to the alien device. $ mount -o degraded /dev/sdc /btrfs [2] mount: wrong fs type, bad option, bad superblock on /dev/sdc, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so. kernel: BTRFS warning (device sdc): devid 1 uuid 072a0192-675b-4d5a-8640-a5cf2b2c704d is missing kernel: BTRFS error (device sdc): failed to read devices kernel: BTRFS error (device sdc): open_ctree failed Fix the root of the issue, by checking if the the device is not missing before it can be a contender for the fs_devices::latest_bdev title. Signed-off-by: Anand Jain Reviewed-by: Josef Bacik --- v3-rebased: update change log. v4: update change log. fs/btrfs/volumes.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index bf953c4895f3..f93739afe681 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1042,6 +1042,8 @@ void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step) &device->dev_state)) { if (!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state) && + !test_bit(BTRFS_DEV_STATE_MISSING, + &device->dev_state) && (!latest_dev || device->generation > latest_dev->generation)) { latest_dev = device; -- 2.25.1