From patchwork Wed Feb 11 09:55:32 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhaolei X-Patchwork-Id: 5811631 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 6DED89F30C for ; Wed, 11 Feb 2015 09:56:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 60AFE20225 for ; Wed, 11 Feb 2015 09:56:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 196DB2021A for ; Wed, 11 Feb 2015 09:56:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751894AbbBKJ4p (ORCPT ); Wed, 11 Feb 2015 04:56:45 -0500 Received: from cn.fujitsu.com ([59.151.112.132]:17348 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751418AbbBKJ4n (ORCPT ); Wed, 11 Feb 2015 04:56:43 -0500 X-IronPort-AV: E=Sophos;i="5.04,848,1406563200"; d="scan'208";a="57440314" Received: from unknown (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 11 Feb 2015 17:53:08 +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 t1B9ttUr025797 for ; Wed, 11 Feb 2015 17:55:56 +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; Wed, 11 Feb 2015 17:56:44 +0800 From: Zhaolei To: CC: Zhao Lei Subject: [PATCH] btrfs: Fix out-of-space bug Date: Wed, 11 Feb 2015 17:55:32 +0800 Message-ID: <1423648532-25535-1-git-send-email-zhaolei@cn.fujitsu.com> X-Mailer: git-send-email 1.8.5.1 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 Btrfs will report NO_SPACE when we create and remove files for several times, and we can't write to filesystem until mount it again. Steps to reproduce: 1: Create a single-dev btrfs fs with default option 2: Write a file into it to take up most fs space 3: Delete above file 4: Wait about 100s to let chunk removed 5: goto 2 Script is like following: #!/bin/bash # Recommend 1.2G space, too large disk will make test slow DEV="/dev/sda16" MNT="/mnt/tmp" dev_size="$(lsblk -bn -o SIZE "$DEV")" || exit 2 file_size_m=$((dev_size * 75 / 100 / 1024 / 1024)) echo "Loop write ${file_size_m}M file on $((dev_size / 1024 / 1024))M dev" for ((i = 0; i < 10; i++)); do umount "$MNT" 2>/dev/null; done echo "mkfs $DEV" mkfs.btrfs -f "$DEV" >/dev/null || exit 2 echo "mount $DEV $MNT" mount "$DEV" "$MNT" || exit 2 for ((loop_i = 0; loop_i < 20; loop_i++)); do echo echo "loop $loop_i" echo "dd file..." cmd=(dd if=/dev/zero of="$MNT"/file0 bs=1M count="$file_size_m") "${cmd[@]}" 2>/dev/null || { # NO_SPACE error triggered echo "dd failed: ${cmd[*]}" exit 1 } echo "rm file..." rm -f "$MNT"/file0 || exit 2 for ((i = 0; i < 10; i++)); do df "$MNT" | tail -1 sleep 10 done done Reason: It is triggered by commit: 47ab2a6c689913db23ccae38349714edf8365e0a which is used to remove empty block groups automatically, but the reason is not in that patch. Code before works well because btrfs don't need to create and delete chunks so many times with high complexity. Above bug is caused by many reason, any of them can trigger it. Reason1: btrfs_check_data_free_space() try to commit transaction and retry allocating chunk when the first allocating failed, but space_info->full is set in first allocating, and prevent second allocating in retry. When we commit transaction with removed bgs, we need to clear space_info->full. Fixed in this patch. Reason2: When we remove some continuous chunks but leave other chunks after, these disk space should be used by chunk-recreating, but in current code, only first create will successed. Fixed by Forrest Liu in: Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole Reason3: contains_pending_extent() return wrong value in calculation. Fixed by Forrest Liu in: Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole Changelog v2->v3: v2 fixed the bug by adding more commit-transaction, but we only need to reclaim space when we are really have no space for new chunk. Actually, code already have this type of commit-and-retry, we only need to make it working with removed-bgs. v3 fixed the bug by above way. Changelog v1->v2: v1 will introduce a new bug when delete and create chunk in same disk space in same transaction, noticed by: Filipe David Manana V2 fix this bug by commit transaction after remove block grops. Tested for severial times by above script. Signed-off-by: Zhao Lei --- fs/btrfs/transaction.c | 4 ++++ fs/btrfs/transaction.h | 5 +++++ fs/btrfs/volumes.c | 2 ++ 3 files changed, 11 insertions(+) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 8cc0e97..f9299f3 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -220,6 +220,7 @@ loop: * commit the transaction. */ atomic_set(&cur_trans->use_count, 2); + atomic_set(&cur_trans->have_free_bgs, 0); cur_trans->start_time = get_seconds(); cur_trans->delayed_refs.href_root = RB_ROOT; @@ -2030,6 +2031,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, btrfs_finish_extent_commit(trans, root); + if (atomic_read(&cur_trans->have_free_bgs)) + btrfs_clear_space_info_full(root->fs_info); + root->fs_info->last_trans_committed = cur_trans->transid; /* * We needn't acquire the lock here because there is no other task diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index 00ed29c..5225326 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -47,6 +47,11 @@ struct btrfs_transaction { atomic_t num_writers; atomic_t use_count; + /* + * true if there is free bgs operations in this transaction + */ + atomic_t have_free_bgs; + /* Be protected by fs_info->trans_lock when we want to change it. */ enum btrfs_trans_state state; struct list_head list; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index ba9857d..46495a1 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1323,6 +1323,8 @@ again: if (ret) { btrfs_error(root->fs_info, ret, "Failed to remove dev extent item"); + } else { + atomic_set(&trans->transaction->have_free_bgs, 1); } out: btrfs_free_path(path);