From patchwork Fri Apr 3 12:12:01 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhaolei X-Patchwork-Id: 6156131 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 8A4CC9F1BE for ; Fri, 3 Apr 2015 12:13:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 92376203F1 for ; Fri, 3 Apr 2015 12:13:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 935AD203A9 for ; Fri, 3 Apr 2015 12:13:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752864AbbDCMNr (ORCPT ); Fri, 3 Apr 2015 08:13:47 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:11951 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752215AbbDCMNp (ORCPT ); Fri, 3 Apr 2015 08:13:45 -0400 X-IronPort-AV: E=Sophos;i="5.04,848,1406563200"; d="scan'208";a="90161341" Received: from localhost (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 03 Apr 2015 20:09:57 +0800 Received: from G08CNEXCHPEKD03.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id t33CCb3V020617 for ; Fri, 3 Apr 2015 20:12:37 +0800 Received: from localhost.localdomain (10.167.226.114) by G08CNEXCHPEKD03.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server id 14.3.181.6; Fri, 3 Apr 2015 20:13:48 +0800 From: Zhaolei To: CC: Zhao Lei Subject: [PATCH 6/9] btrfs: Fix NO_SPACE bug caused by delayed-iput Date: Fri, 3 Apr 2015 20:12:01 +0800 Message-ID: <0285fb7e3d3ec80b5dd6c977a1f1f32551d73005.1428062473.git.zhaolei@cn.fujitsu.com> X-Mailer: git-send-email 1.8.5.1 In-Reply-To: References: MIME-Version: 1.0 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, 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 From: Zhao Lei Steps to reproduce: while true; do dd if=/dev/zero of=/btrfs_dir/file count=[fs_size * 75%] rm /btrfs_dir/file sync done And we'll see dd failed because btrfs return NO_SPACE. Reason: Normally, btrfs_commit_transaction() call btrfs_run_delayed_iputs() in end to free fs space for next write, but sometimes it hadn't done work on time, because btrfs-cleaner thread get delayed-iputs from list before, but do iput() after next write. This is log: [ 2569.050776] comm=btrfs-cleaner func=btrfs_evict_inode() begin [ 2569.084280] comm=sync func=btrfs_commit_transaction() call btrfs_run_delayed_iputs() [ 2569.085418] comm=sync func=btrfs_commit_transaction() done btrfs_run_delayed_iputs() [ 2569.087554] comm=sync func=btrfs_commit_transaction() end [ 2569.191081] comm=dd begin [ 2569.790112] comm=dd func=__btrfs_buffered_write() ret=-28 [ 2569.847479] comm=btrfs-cleaner func=add_pinned_bytes() 0 + 32677888 = 32677888 [ 2569.849530] comm=btrfs-cleaner func=add_pinned_bytes() 32677888 + 23834624 = 56512512 ... [ 2569.903893] comm=btrfs-cleaner func=add_pinned_bytes() 943976448 + 21762048 = 965738496 [ 2569.908270] comm=btrfs-cleaner func=btrfs_evict_inode() end Fix: Make btrfs_commit_transaction() wait current running btrfs-cleaner's delayed-iputs() done in end. Test: Use script similar to above(more complex), before patch: 7 failed in 100 * 20 loop. after patch: 0 failed in 100 * 20 loop. Signed-off-by: Zhao Lei --- fs/btrfs/ctree.h | 1 + fs/btrfs/disk-io.c | 5 ++++- fs/btrfs/transaction.c | 6 +++++- 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index f9c89ca..54d4d78 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1513,6 +1513,7 @@ struct btrfs_fs_info { spinlock_t delayed_iput_lock; struct list_head delayed_iputs; + struct rw_semaphore delayed_iput_sem; /* this protects tree_mod_seq_list */ spinlock_t tree_mod_seq_lock; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 639f266..df40f60 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1778,7 +1778,9 @@ static int cleaner_kthread(void *arg) goto sleep; } + down_read(&root->fs_info->delayed_iput_sem); btrfs_run_delayed_iputs(root); + up_read(&root->fs_info->delayed_iput_sem); btrfs_delete_unused_bgs(root->fs_info); again = btrfs_clean_one_deleted_snapshot(root); mutex_unlock(&root->fs_info->cleaner_mutex); @@ -2241,11 +2243,12 @@ int open_ctree(struct super_block *sb, spin_lock_init(&fs_info->qgroup_op_lock); spin_lock_init(&fs_info->buffer_lock); spin_lock_init(&fs_info->unused_bgs_lock); - mutex_init(&fs_info->unused_bg_unpin_mutex); rwlock_init(&fs_info->tree_mod_log_lock); + mutex_init(&fs_info->unused_bg_unpin_mutex); mutex_init(&fs_info->reloc_mutex); mutex_init(&fs_info->delalloc_root_mutex); seqlock_init(&fs_info->profiles_lock); + init_rwsem(&fs_info->delayed_iput_sem); init_completion(&fs_info->kobj_unregister); INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 8be4278..d18991f 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -2076,8 +2076,12 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, kmem_cache_free(btrfs_trans_handle_cachep, trans); - if (current != root->fs_info->transaction_kthread) + if (current != root->fs_info->transaction_kthread) { btrfs_run_delayed_iputs(root); + /* make sure that all running delayed iput are done */ + down_write(&root->fs_info->delayed_iput_sem); + up_write(&root->fs_info->delayed_iput_sem); + } return ret;