OCFS2_LOCK_NONBLOCK
ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
if (wait && arg_flags & OCFS2_LOCK_NONBLOCK &&
ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);