OCFS2/DLM/dlm response msg

#define OCFS2_MESSAGE_TYPE_VOTE     (0x1)
#define OCFS2_MESSAGE_TYPE_RESPONSE (0x2)
struct ocfs2_msg_hdr
{
        __be32 h_response_id; /* used to lookup message handle on sending
                            * node. */
        __be32 h_request;
        __be64 h_blkno;
        __be32 h_generation;
        __be32 h_node_num;    /* node sending this particular message. */
};

/* Responses are given these values to maintain backwards
 * compatibility with older ocfs2 versions */
#define OCFS2_RESPONSE_OK               (0)
#define OCFS2_RESPONSE_BUSY             (-16)
#define OCFS2_RESPONSE_BAD_MSG          (-22)

struct ocfs2_response_msg
{
        struct ocfs2_msg_hdr r_hdr;
        __be32 r_response;
        __be32 r_orphaned_slot;
};