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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef DM_STATS_H3#define DM_STATS_H4 5#include <linux/types.h>6#include <linux/mutex.h>7#include <linux/list.h>8 9int dm_statistics_init(void);10void dm_statistics_exit(void);11 12struct 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 bool precise_timestamps;17};18 19struct dm_stats_aux {20 bool merged;21 unsigned long long duration_ns;22};23 24int dm_stats_init(struct dm_stats *st);25void dm_stats_cleanup(struct dm_stats *st);26 27struct mapped_device;28 29int dm_stats_message(struct mapped_device *md, unsigned int argc, char **argv,30 char *result, unsigned int maxlen);31 32void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,33 sector_t bi_sector, unsigned int bi_sectors, bool end,34 unsigned long start_time,35 struct dm_stats_aux *aux);36 37static inline bool dm_stats_used(struct dm_stats *st)38{39 return !list_empty(&st->list);40}41 42static inline void dm_stats_record_start(struct dm_stats *stats, struct dm_stats_aux *aux)43{44 if (unlikely(stats->precise_timestamps))45 aux->duration_ns = ktime_to_ns(ktime_get());46}47 48#endif49