From patchwork Tue Nov 29 04:42:39 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 9450937 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 01E9560756 for ; Tue, 29 Nov 2016 04:43:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EF4872675C for ; Tue, 29 Nov 2016 04:43:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E393926E64; Tue, 29 Nov 2016 04:43:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 88FF226E64 for ; Tue, 29 Nov 2016 04:43:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932582AbcK2Eny (ORCPT ); Mon, 28 Nov 2016 23:43:54 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:56327 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753016AbcK2Env (ORCPT ); Mon, 28 Nov 2016 23:43:51 -0500 X-IronPort-AV: E=Sophos;i="5.20,367,1444665600"; d="scan'208";a="989256" Received: from unknown (HELO cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 29 Nov 2016 12:43:00 +0800 Received: from localhost.localdomain (unknown [10.167.226.34]) by cn.fujitsu.com (Postfix) with ESMTP id DAF8741B4BDF for ; Tue, 29 Nov 2016 12:42:56 +0800 (CST) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH 1/3] btrfs: qgroup: Fix qgroup corruption caused by inode_cache mount option Date: Tue, 29 Nov 2016 12:42:39 +0800 Message-Id: <20161129044241.27407-2-quwenruo@cn.fujitsu.com> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161129044241.27407-1-quwenruo@cn.fujitsu.com> References: <20161129044241.27407-1-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 X-yoursite-MailScanner-ID: DAF8741B4BDF.A174A X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: quwenruo@cn.fujitsu.com Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP [BUG] The easist way to reproduce the bug is: ------ # mkfs.btrfs -f $dev -n 16K # mount $dev $mnt -o inode_cache # btrfs quota enable $mnt # btrfs quota rescan -w $mnt # btrfs qgroup show $mnt qgroupid rfer excl -------- ---- ---- 0/5 32.00KiB 32.00KiB ^^ Twice the correct value ------ And fstests/btrfs qgroup test group can easily detect them with inode_cache mount option. Although some of them are false alerts since old test cases are using fixed golden output. While new test cases will use "btrfs check" to detect qgroup mismatch. [CAUSE] Inode_cache mount option will make commit_fs_roots() to call btrfs_save_ino_cache() to update fs/subvol trees, and generate new delayed refs. However we call btrfs_qgroup_prepare_account_extents() too early, before commit_fs_roots(). This makes the "old_roots" for newly generated extents are always NULL. For freeing extent case, this makes both new_roots and old_roots to be empty, while correct old_roots should not be empty. This causing qgroup numbers not decreased correctly. [FIX] Modify the timing of calling btrfs_qgroup_prepare_account_extents() to just before btrfs_qgroup_account_extents(), and add needed delayed_refs handler. So qgroup can handle inode_map mount options correctly. Signed-off-by: Qu Wenruo --- fs/btrfs/transaction.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index e66a18e..f65659b 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -2102,13 +2102,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, goto scrub_continue; } - /* Reocrd old roots for later qgroup accounting */ - ret = btrfs_qgroup_prepare_account_extents(trans, root->fs_info); - if (ret) { - mutex_unlock(&root->fs_info->reloc_mutex); - goto scrub_continue; - } - /* * make sure none of the code above managed to slip in a * delayed item @@ -2151,6 +2144,22 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, btrfs_free_log_root_tree(trans, root->fs_info); /* + * commit_fs_roots() can call btrfs_save_ino_cache(), which generates + * new delayed refs. Must handle them or qgroup can be wrong. + */ + ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); + if (ret) { + mutex_unlock(&root->fs_info->reloc_mutex); + goto scrub_continue; + } + + ret = btrfs_qgroup_prepare_account_extents(trans, root->fs_info); + if (ret) { + mutex_unlock(&root->fs_info->reloc_mutex); + goto scrub_continue; + } + + /* * Since fs roots are all committed, we can get a quite accurate * new_roots. So let's do quota accounting. */