From patchwork Tue Nov 3 20:36:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 316977 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 E6D2EC388F7 for ; Tue, 3 Nov 2020 21:21:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DBFF206E3 for ; Tue, 3 Nov 2020 21:21:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604438502; bh=qYF6BAh2DEufx/w93fuY7ZrcXjDyzsulL6SOF3/BtoE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=guYUvcKQ10IUKOZdK7Vl55haKAK4GnmgS4dLwCap/M/TrftyZRR31K8DfhRls4gIN uHRyYQ98Okh24IzkD3eDszJ8bS4uV0Qai0Wa39iIkQRkVwPPGwmfOcT0GkMqQX026a O73K/rI8w3r0KgD7Cci08tT5YjnrvoyrV2aEyKtM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731917AbgKCVVl (ORCPT ); Tue, 3 Nov 2020 16:21:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:44920 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388110AbgKCVGH (ORCPT ); Tue, 3 Nov 2020 16:06:07 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 B6D6F20757; Tue, 3 Nov 2020 21:06:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604437566; bh=qYF6BAh2DEufx/w93fuY7ZrcXjDyzsulL6SOF3/BtoE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YAKHYwMsvVVR96zoLOjNpoqF8AmbI9ZgjbByTqWpbdhfgKNu7GNB+SyqmGHjXMiSA 06wU352L7oz9fJ3WWabQLbo+pFiv9liIKxj6x3xnaSdJdCicvYEP2D8c27I0qbSka3 YZAD9m2WP6uy9AuRK6LwL2csuFxMAy//IJLRXQ8U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anand Jain , David Sterba , Sasha Levin Subject: [PATCH 4.19 093/191] btrfs: fix replace of seed device Date: Tue, 3 Nov 2020 21:36:25 +0100 Message-Id: <20201103203242.606198520@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103203232.656475008@linuxfoundation.org> References: <20201103203232.656475008@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Anand Jain [ Upstream commit c6a5d954950c5031444173ad2195efc163afcac9 ] 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 /dev/sda $ btrfstune -S1 /dev/sda $ mount /dev/sda /btrfs $ btrfs device add /dev/sdb /btrfs $ umount /btrfs $ btrfs device scan --forget $ mount -o device=/dev/sda /dev/sdb /btrfs $ btrfs replace 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 device 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 inspect-internal 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 device scan --forget $ mount -o device=/dev/sda /dev/sdb /btrfs Fix in this patch: If a seed is not sprouted then there is no replacement of it, because of its read-only filesystem with a read-only device. Similarly, in the case of a sprouted filesystem, the seed device is still read only. So, mark 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. Signed-off-by: Anand Jain Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- 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 1b9c8ffb038ff..36c0490156ac5 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -190,7 +190,7 @@ 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; }