From: Yongqiang Yang Subject: [PATCH 2/2] ext4: check free inode count before allocaing an inode Date: Sun, 2 Sep 2012 17:45:09 +0800 Message-ID: <1346579109-25016-2-git-send-email-xiaoqiangnk@gmail.com> References: <1346579109-25016-1-git-send-email-xiaoqiangnk@gmail.com> Cc: tytso@mit.edu, Yongqiang Yang To: linux-ext4@vger.kernel.org Return-path: Received: from mail-pz0-f46.google.com ([209.85.210.46]:49383 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755938Ab2IBKUg (ORCPT ); Sun, 2 Sep 2012 06:20:36 -0400 Received: by mail-pz0-f46.google.com with SMTP id y13so3013380dad.19 for ; Sun, 02 Sep 2012 03:20:36 -0700 (PDT) In-Reply-To: <1346579109-25016-1-git-send-email-xiaoqiangnk@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Recnetly, I ecountered some corrupted filesystems in which some groups' free inode counts were negative, it seemed that free inode count was overflow. This patch teaches ext4 to check free inode count before allocaing an inode. Signed-off-by: Yongqiang Yang --- fs/ext4/ialloc.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 26154b8..fa36372 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -697,6 +697,15 @@ got_group: if (!gdp) goto fail; + /* + * Check free inodes count before loading bitmap. + */ + if (ext4_free_inodes_count(sb, gdp) == 0) { + if (++group == ngroups) + group = 0; + continue; + } + brelse(inode_bitmap_bh); inode_bitmap_bh = ext4_read_inode_bitmap(sb, group); if (!inode_bitmap_bh) -- 1.7.5.1