From patchwork Sun Sep 2 09:45:09 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [2/2] ext4: check free inode count before allocaing an inode Date: Sat, 01 Sep 2012 23:45:09 -0000 From: Yongqiang Yang X-Patchwork-Id: 181174 Message-Id: <1346579109-25016-2-git-send-email-xiaoqiangnk@gmail.com> To: linux-ext4@vger.kernel.org Cc: tytso@mit.edu, Yongqiang Yang 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)