From patchwork Thu May 17 07:35:39 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tao Ma X-Patchwork-Id: 159843 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id EE193B6FBB for ; Thu, 17 May 2012 17:36:14 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761307Ab2EQHfx (ORCPT ); Thu, 17 May 2012 03:35:53 -0400 Received: from oproxy6-pub.bluehost.com ([67.222.54.6]:36024 "HELO oproxy6-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1761292Ab2EQHfu (ORCPT ); Thu, 17 May 2012 03:35:50 -0400 Received: (qmail 3379 invoked by uid 0); 17 May 2012 07:35:50 -0000 Received: from unknown (HELO box585.bluehost.com) (66.147.242.185) by cpoproxy3.bluehost.com with SMTP; 17 May 2012 07:35:50 -0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tao.ma; s=default; h=Message-Id:Date:Subject:Cc:To:From; bh=rYp6frEqmCx3S8Xa7IMBiSVEnw3QZrRcJkzau+Xrmf0=; b=xVE4dvng5NPR93xwXsBxSkQNIJbtVwQC6tjoOJoHCAzQEgdA7/TtW3uKm4j4cXqhtZaaUZ0QKVJCyqYozdQqDuMEnJekUBOFr5U4OOBQjYddmgGPphg3S0t7vd6MwgOX; Received: from [182.92.247.2] (helo=tma-laptop1.taobao.ali.com) by box585.bluehost.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.76) (envelope-from ) id 1SUvFV-0008QK-Om; Thu, 17 May 2012 01:35:50 -0600 From: Tao Ma To: linux-ext4@vger.kernel.org Cc: Theodore Ts'o Subject: [PATCH V2] ext4: Protect group inode free counting with group lock. Date: Thu, 17 May 2012 15:35:39 +0800 Message-Id: <1337240139-5005-1-git-send-email-tm@tao.ma> X-Mailer: git-send-email 1.7.4.1 X-Identified-User: {1390:box585.bluehost.com:colyli:tao.ma} {sentby:smtp auth 182.92.247.2 authed with tm@tao.ma} Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Tao Ma Now when we set the group inode free count, we don't have a proper group lock so that multiple threads may decrease the inode free count at the same time. And e2fsck will complain something like: Free inodes count wrong for group #1 (1, counted=0). Fix? no Free inodes count wrong for group #2 (3, counted=0). Fix? no Directories count wrong for group #2 (780, counted=779). Fix? no Free inodes count wrong for group #3 (2272, counted=2273). Fix? no So this patch try to protect it with the ext4_lock_group. btw, it is found by xfstests test case 269 and the volume is mkfsed with the parameter "-O ^resize_inode,^uninit_bg,extent,meta_bg,flex_bg,ext_attr" and I have run it 100 times and the error in e2fsck doesn't show up again. Cc: Theodore Ts'o Signed-off-by: Tao Ma --- fs/ext4/ialloc.c | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 409c2ee..ca533d7 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -772,7 +772,10 @@ got: ext4_itable_unused_set(sb, gdp, (EXT4_INODES_PER_GROUP(sb) - ino)); up_read(&grp->alloc_sem); + } else { + ext4_lock_group(sb, group); } + ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1); if (S_ISDIR(mode)) { ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1); @@ -782,10 +785,9 @@ got: atomic_inc(&sbi->s_flex_groups[f].used_dirs); } } - if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) { + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp); - ext4_unlock_group(sb, group); - } + ext4_unlock_group(sb, group); BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);