union v_atomic records_count; /* Number of records written */
union v_atomic records_overrun; /* Number of overwritten records */
wait_queue_head_t read_wait; /* reader buffer-level wait queue */
+ wait_queue_head_t write_wait; /* writer buffer-level wait queue (for metadata only) */
int finalized; /* buffer has been finalized */
struct timer_list switch_timer; /* timer for periodical switch */
struct timer_list read_timer; /* timer for read poll */