1#ifndef DM_STATS_H
2#define DM_STATS_H
3
4#include <linux/types.h>
5#include <linux/mutex.h>
6#include <linux/list.h>
7
8int dm_statistics_init(void);
9void dm_statistics_exit(void);
10
11struct dm_stats {
12	struct mutex mutex;
13	struct list_head list;	/* list of struct dm_stat */
14	struct dm_stats_last_position __percpu *last;
15	sector_t last_sector;
16	unsigned last_rw;
17};
18
19struct dm_stats_aux {
20	bool merged;
21};
22
23void dm_stats_init(struct dm_stats *st);
24void dm_stats_cleanup(struct dm_stats *st);
25
26struct mapped_device;
27
28int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
29		     char *result, unsigned maxlen);
30
31void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
32			 sector_t bi_sector, unsigned bi_sectors, bool end,
33			 unsigned long duration, struct dm_stats_aux *aux);
34
35static inline bool dm_stats_used(struct dm_stats *st)
36{
37	return !list_empty(&st->list);
38}
39
40#endif
41