From patchwork Thu Jun 26 03:08:16 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Shilong X-Patchwork-Id: 4425571 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 240E3BEEAA for ; Thu, 26 Jun 2014 03:13:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 476DE2037F for ; Thu, 26 Jun 2014 03:13:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6582B2037B for ; Thu, 26 Jun 2014 03:13:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755309AbaFZDM2 (ORCPT ); Wed, 25 Jun 2014 23:12:28 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:13024 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754834AbaFZDM2 (ORCPT ); Wed, 25 Jun 2014 23:12:28 -0400 X-IronPort-AV: E=Sophos;i="5.00,779,1396972800"; d="scan'208";a="32452256" Received: from unknown (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 26 Jun 2014 11:09:45 +0800 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id s5Q3COqL027977 for ; Thu, 26 Jun 2014 11:12:24 +0800 Received: from wangs.fnst.cn.fujitsu.com (10.167.226.245) by G08CNEXCHPEKD02.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.181.6; Thu, 26 Jun 2014 11:12:25 +0800 From: Wang Shilong To: Subject: [PATCH] Btrfs: fix race between balance recovery and root deletion Date: Thu, 26 Jun 2014 11:08:16 +0800 Message-ID: <1403752096-4776-1-git-send-email-wangsl.fnst@cn.fujitsu.com> X-Mailer: git-send-email 1.9.0 MIME-Version: 1.0 X-Originating-IP: [10.167.226.245] 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 Balance recovery is called when RW mounting or remounting from RO to RW, it is called to finish roots merging. When doing balance recovery, relocation root's corresponding fs root(whose root refs is 0) might be destroyed by cleaner thread, this will make btrfs fail to mount. Fix this problem by holding @cleaner_mutex when doing balance recovery. Signed-off-by: Wang Shilong Reviewed-by: David Sterba --- fs/btrfs/disk-io.c | 2 ++ fs/btrfs/super.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 8bb4aa1..61d8e87 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2904,7 +2904,9 @@ retry_root_backup: if (ret) goto fail_qgroup; + mutex_lock(&fs_info->cleaner_mutex); ret = btrfs_recover_relocation(tree_root); + mutex_unlock(&fs_info->cleaner_mutex); if (ret < 0) { printk(KERN_WARNING "BTRFS: failed to recover relocation\n"); diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 4662d92..b6ebde2 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1467,7 +1467,9 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data) goto restore; /* recover relocation */ + mutex_lock(&fs_info->cleaner_mutex); ret = btrfs_recover_relocation(root); + mutex_unlock(&fs_info->cleaner_mutex); if (ret) goto restore;