drivers/md/dm-stats.h

   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