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 44