| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef DM_STATS_H |
| 3 | #define DM_STATS_H |
| 4 | |
| 5 | #include <linux/types.h> |
| 6 | #include <linux/mutex.h> |
| 7 | #include <linux/list.h> |
| 8 | |
| 9 | int dm_statistics_init(void); |
| 10 | void dm_statistics_exit(void); |
| 11 | |
| 12 | struct dm_stats { |
| 13 | struct mutex mutex; |
| 14 | struct list_head list; /* list of struct dm_stat */ |
| 15 | struct dm_stats_last_position __percpu *last; |
| 16 | sector_t last_sector; |
| 17 | unsigned last_rw; |
| 18 | }; |
| 19 | |
| 20 | struct dm_stats_aux { |
| 21 | bool merged; |
| 22 | unsigned long long duration_ns; |
| 23 | }; |
| 24 | |
| 25 | void dm_stats_init(struct dm_stats *st); |
| 26 | void dm_stats_cleanup(struct dm_stats *st); |
| 27 | |
| 28 | struct mapped_device; |
| 29 | |
| 30 | int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv, |
| 31 | char *result, unsigned maxlen); |
| 32 | |
| 33 | void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw, |
| 34 | sector_t bi_sector, unsigned bi_sectors, bool end, |
| 35 | unsigned long duration_jiffies, |
| 36 | struct dm_stats_aux *aux); |
| 37 | |
| 38 | static inline bool dm_stats_used(struct dm_stats *st) |
| 39 | { |
| 40 | return !list_empty(&st->list); |
| 41 | } |
| 42 | |
| 43 | #endif |