From patchwork Mon Aug 31 18:48:24 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sam Tygier X-Patchwork-Id: 7101171 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 77E7E9F1D5 for ; Mon, 31 Aug 2015 18:48:45 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9A55A206D4 for ; Mon, 31 Aug 2015 18:48:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF562205EC for ; Mon, 31 Aug 2015 18:48:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754160AbbHaSsk (ORCPT ); Mon, 31 Aug 2015 14:48:40 -0400 Received: from plane.gmane.org ([80.91.229.3]:42357 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754121AbbHaSsj (ORCPT ); Mon, 31 Aug 2015 14:48:39 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1ZWU8B-0000RQ-Je for linux-btrfs@vger.kernel.org; Mon, 31 Aug 2015 20:48:35 +0200 Received: from host-78-149-214-125.as13285.net ([78.149.214.125]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 31 Aug 2015 20:48:35 +0200 Received: from samtygier by host-78-149-214-125.as13285.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 31 Aug 2015 20:48:35 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: linux-btrfs@vger.kernel.org From: sam tygier Subject: [PATCH] Btrfs: Check metadata redundancy on balance Date: Mon, 31 Aug 2015 19:48:24 +0100 Lines: 80 Message-ID: Mime-Version: 1.0 X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: host-78-149-214-125.as13285.net User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.7.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, FREEMAIL_FROM,RCVD_IN_DNSWL_HI,T_RP_MATCHES_RCVD,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Resending, as I received no comments on previous submission. Currently BTRFS allows you to make bad choices of data and metadata levels. For example -d raid1 -m raid0 means you can only use half your total disk space, but will loose everything if 1 disk fails. It should give a warning in these cases. This patch is a follow up to [PATCH v2] btrfs-progs: check metadata redundancy in order to cover the case of using balance to convert to such a set of raid levels. A simple example to hit this is to create a single device fs, which will default to single:dup, then to add a second device and attempt to convert to raid1 with the command btrfs balance start -dconvert=raid1 /mnt this will result in a filesystem with raid1:dup, which will not survive the loss of one drive. I personally don't see why the tools should allow this, but in the previous thread a warning was considered sufficient. Signed-off-by: Sam Tygier From: Sam Tygier Date: Sat, 13 Jun 2015 18:13:06 +0100 Subject: [PATCH] Btrfs: Check metadata redundancy on balance When converting a filesystem via balance check that metadata mode is at least as redundant as the data mode. For example give warning when: -dconvert=raid1 -mconvert=single --- fs/btrfs/volumes.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index fbe7c10..a0ce1f7 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -3454,6 +3454,24 @@ static void __cancel_balance(struct btrfs_fs_info *fs_info) atomic_set(&fs_info->mutually_exclusive_operation_running, 0); } +static int group_profile_max_safe_loss(u64 flag) +{ + switch (flag & BTRFS_BLOCK_GROUP_PROFILE_MASK) { + case 0: /* single */ + case BTRFS_BLOCK_GROUP_DUP: + case BTRFS_BLOCK_GROUP_RAID0: + return 0; + case BTRFS_BLOCK_GROUP_RAID1: + case BTRFS_BLOCK_GROUP_RAID5: + case BTRFS_BLOCK_GROUP_RAID10: + return 1; + case BTRFS_BLOCK_GROUP_RAID6: + return 2; + default: + return -1; + } +} + /* * Should be called with both balance and volume mutexes held */ @@ -3572,6 +3590,12 @@ int btrfs_balance(struct btrfs_balance_control *bctl, } } while (read_seqretry(&fs_info->profiles_lock, seq)); + if (group_profile_max_safe_loss(bctl->meta.target) < + group_profile_max_safe_loss(bctl->data.target)){ + btrfs_info(fs_info, + "Warning: metatdata has lower redundancy than data\n"); + } + if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) { int num_tolerated_disk_barrier_failures; u64 target = bctl->sys.target;