From patchwork Sun Aug 30 14:41:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anand Jain X-Patchwork-Id: 11745165 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 21A35739 for ; Sun, 30 Aug 2020 14:42:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 04ACD20BED for ; Sun, 30 Aug 2020 14:42:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="wLSH7qhK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727923AbgH3Oms (ORCPT ); Sun, 30 Aug 2020 10:42:48 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:59260 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727031AbgH3Olt (ORCPT ); Sun, 30 Aug 2020 10:41:49 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 07UEXTup130503; Sun, 30 Aug 2020 14:41:43 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=corp-2020-01-29; bh=d6xvwbbwFUIhyKqCryBUp8S2eSdVOnERyU3Mb8S9Vzo=; b=wLSH7qhK330rguUNTX8R2tDPCa5hAFomLmlOloasDn6MR257NE7Lk1YPr70EpQaeE9YB JSEqhL8+p5X5r0+H3QkDVa35/D/rRIr6GMWwRgZQwgzRyw1BSIho7WxYVvOetArQMlZI uLDeKXmxefkMz659PmSQJX+P00P69Y49EJK5Rc0Ykq+cfURVWvz+GiP/KM5uSvn4KV8b VD1NlH3TqgdvNNCavKPHRP2tybzR4WDnsRfr6Pje+sl/Yr04aXdgshY76VLHYQkz4zZR gxOa9c/B0CcB3WsmPqx6Ssi4B0xPl7q7/FomiaJJdhZbqwefY30egOW57bMVM427KlyI XQ== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 337qrha2d9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Sun, 30 Aug 2020 14:41:43 +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 07UEZYmK153287; Sun, 30 Aug 2020 14:41:43 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 3380xtr40t-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 30 Aug 2020 14:41:43 +0000 Received: from abhmp0012.oracle.com (abhmp0012.oracle.com [141.146.116.18]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 07UEfgoC015607; Sun, 30 Aug 2020 14:41:42 GMT Received: from localhost.localdomain (/39.109.231.106) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Sun, 30 Aug 2020 07:41:41 -0700 From: Anand Jain To: linux-btrfs@vger.kernel.org Cc: dsterba@suse.com, josef@toxicpanda.com Subject: [PATCH 11/11] btrfs: fix replace of seed device Date: Sun, 30 Aug 2020 22:41:06 +0800 Message-Id: <660ee9f002a792a5d4b682779d72803de4767f4a.1598792561.git.anand.jain@oracle.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9729 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 adultscore=0 phishscore=0 malwarescore=0 bulkscore=0 mlxscore=0 mlxlogscore=999 suspectscore=1 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008300118 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9729 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 bulkscore=0 adultscore=0 mlxscore=0 lowpriorityscore=0 phishscore=0 clxscore=1015 suspectscore=1 priorityscore=1501 spamscore=0 malwarescore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008300118 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org If you replace a seed device in a sprouted fs, it appears to have successfully replaced the seed device, but if you look closely, it didn't. Here is an example. mkfs.btrfs -fq /dev/sda btrfstune -S1 /dev/sda mount /dev/sda /btrfs btrfs dev add /dev/sdb /btrfs umount /btrfs; btrfs dev scan --forget mount -o device=/dev/sda /dev/sdb /btrfs btrfs rep start -f /dev/sda /dev/sdc /btrfs; echo $? 0 BTRFS info (device sdb): dev_replace from /dev/sda (devid 1) to /dev/sdc started BTRFS info (device sdb): dev_replace from /dev/sda (devid 1) to /dev/sdc finished btrfs fi show Label: none uuid: ab2c88b7-be81-4a7e-9849-c3666e7f9f4f Total devices 2 FS bytes used 256.00KiB devid 1 size 3.00GiB used 520.00MiB path /dev/sdc devid 2 size 3.00GiB used 896.00MiB path /dev/sdb Label: none uuid: 10bd3202-0415-43af-96a8-d5409f310a7e Total devices 1 FS bytes used 128.00KiB devid 1 size 3.00GiB used 536.00MiB path /dev/sda So as per the replace start command and kernel log replace was successful. Now let's try to clean mount. umount /btrfs; btrfs dev scan --forget mount -o device=/dev/sdc /dev/sdb /btrfs mount: /btrfs: wrong fs type, bad option, bad superblock on /dev/sdb, missing codepage or helper program, or other error. [ 636.157517] BTRFS error (device sdc): failed to read chunk tree: -2 [ 636.180177] BTRFS error (device sdc): open_ctree failed That's because per dev items it is still looking for the original seed device. btrfs in dump-tree -d /dev/sdb item 0 key (DEV_ITEMS DEV_ITEM 1) itemoff 16185 itemsize 98 devid 1 total_bytes 3221225472 bytes_used 545259520 io_align 4096 io_width 4096 sector_size 4096 type 0 generation 6 start_offset 0 dev_group 0 seek_speed 0 bandwidth 0 uuid 59368f50-9af2-4b17-91da-8a783cc418d4 <--- seed uuid fsid 10bd3202-0415-43af-96a8-d5409f310a7e <--- seed fsid item 1 key (DEV_ITEMS DEV_ITEM 2) itemoff 16087 itemsize 98 devid 2 total_bytes 3221225472 bytes_used 939524096 io_align 4096 io_width 4096 sector_size 4096 type 0 generation 0 start_offset 0 dev_group 0 seek_speed 0 bandwidth 0 uuid 56a0a6bc-4630-4998-8daf-3c3030c4256a <- sprout uuid fsid ab2c88b7-be81-4a7e-9849-c3666e7f9f4f <- sprout fsid But the replaced target has the following uuid+fsid in its superblock which doesn't match with the expected uuid+fsid in its devitem. btrfs in dump-super /dev/sdc | egrep '^generation|dev_item.uuid|dev_item.fsid|devid' generation 20 dev_item.uuid 59368f50-9af2-4b17-91da-8a783cc418d4 dev_item.fsid ab2c88b7-be81-4a7e-9849-c3666e7f9f4f [match] dev_item.devid 1 So if you provide the original seed device the mount shall be successful. Which so long happening in the test case btrfs/163. btrfs dev scan --forget mount -o device=/dev/sda /dev/sdb /btrfs Fix in this patch: Make it as you can't replace a seed device, you can only add a new device and then delete the seed device. If replace is attempted then returns -EINVAL. As in the below changes. Another possible fix: If we want to keep the ability to replace for seed-device, then we could update the fsid of the replace-target blocks. And after replacement, you have seed device but with sprout fsid. But then I don't know what is the point and if there is any such use case. Signed-off-by: Anand Jain --- fs/btrfs/dev-replace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 656d8ba642af..02b7b3edf9a3 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -225,7 +225,7 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info, int ret = 0; *device_out = NULL; - if (fs_info->fs_devices->seeding) { + if (srcdev->fs_devices->seeding) { btrfs_err(fs_info, "the filesystem is a seed filesystem!"); return -EINVAL; }