ocfs2: fix a tiny case that inode can not removed

When running dirop_fileop_racer we found a case that inode
can not removed.

Two nodes, say Node A and Node B, mount the same ocfs2 volume.  Create
two dirs /race/1/ and /race/2/ in the filesystem.

  Node A                            Node B
  rm -r /race/2/
                                    mv /race/1/ /race/2/
  call ocfs2_unlink(), get
  the EX mode of /race/2/
                                    wait for B unlock /race/2/
  decrease i_nlink of /race/2/ to 0,
  and add inode of /race/2/ into
  orphan dir, unlock /race/2/
                                    got EX mode of /race/2/. because
                                    /race/1/ is dir, so inc i_nlink
                                    of /race/2/ and update into disk,
                                    unlock /race/2/
  because i_nlink of /race/2/
  is not zero, this inode will
  always remain in orphan dir

This patch fixes this case by test whether i_nlink of new dir is zero.

Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Xue jiufei <xuejiufei@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index 1c43993..b7dfac2 100644 (file)
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -1309,6 +1309,11 @@ static int ocfs2_rename(struct inode *old_dir,
        }
        parents_locked = 1;
 
+       if (!new_dir->i_nlink) {
+               status = -EACCES;
+               goto bail;
+       }
+
        /* make sure both dirs have bhs
         * get an extra ref on old_dir_bh if old==new */
        if (!new_dir_bh) {