ocfs2: fix ocfs2 corrupt when iputting an inode

ocfs2: fix ocfs2 corrupt when iputting an inode

In this condition, it will cause an bug on error.
ocfs2_mkdir()
  ->ocfs2_mknod()
    ->ocfs2_mknod_locked()
      ->__ocfs2_mknod_locked()
        //Assume inode->i_generation is genN.
        ->inode->i_generation = osb->s_next_generation++;
        // The inode lockres has been initialized.
        ->ocfs2_populate_inode()
        ->ocfs2_create_new_inode_locks()
            ->An error happened, returned value is non-zero
      // free the start_bit x in bg_blkno
      ->ocfs2_free_suballoc_bits()
    ->...  /* Another process execute mkdir success in this place,
              and it occupied the start_bit x in bg_blkno
              which has been freed before. Its inode->i_generation
              is genN + 1 */
    ->iput(inode)
      ->evict()
        ->ocfs2_evict_inode()
          ->ocfs2_delete_inode()
            ->ocfs2_inode_lock()
              ->ocfs2_inode_lock_update()
                /* Bug on here, genN != genN + 1 */
                ->mlog_bug_on_msg(inode->i_generation !=
                  le32_to_cpu(fe->i_generation))

So, we need not to reclaim the inode when the inode->ip_inode_lockres
has been initialized. It will be freed in iput().

Link: http://lkml.kernel.org/r/ef080ca3-5d74-e276-17a1-d9e7c7e662c9@huawei.com
Fixes: b1529a41f777 ("ocfs2: should reclaim the inode if '__ocfs2_mknod_locked' returns an error")
Signed-off-by: Yan Wang <wangyan122@huawei.com>
Reviewed-by: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>