diff options
Diffstat (limited to 'drivers/md/persistent-data/dm-space-map.h')
| -rw-r--r-- | drivers/md/persistent-data/dm-space-map.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/md/persistent-data/dm-space-map.h b/drivers/md/persistent-data/dm-space-map.h index 1cbfc6b1638a..3e6d1153b7c4 100644 --- a/drivers/md/persistent-data/dm-space-map.h +++ b/drivers/md/persistent-data/dm-space-map.h @@ -9,6 +9,8 @@ #include "dm-block-manager.h" +typedef void (*dm_sm_threshold_fn)(void *context); + /* * struct dm_space_map keeps a record of how many times each block in a device * is referenced. It needs to be fixed on disk as part of the transaction. @@ -59,6 +61,15 @@ struct dm_space_map { */ int (*root_size)(struct dm_space_map *sm, size_t *result); int (*copy_root)(struct dm_space_map *sm, void *copy_to_here_le, size_t len); + + /* + * You can register one threshold callback which is edge-triggered + * when the free space in the space map drops below the threshold. + */ + int (*register_threshold_callback)(struct dm_space_map *sm, + dm_block_t threshold, + dm_sm_threshold_fn fn, + void *context); }; /*----------------------------------------------------------------*/ @@ -131,4 +142,16 @@ static inline int dm_sm_copy_root(struct dm_space_map *sm, void *copy_to_here_le return sm->copy_root(sm, copy_to_here_le, len); } +static inline int dm_sm_register_threshold_callback(struct dm_space_map *sm, + dm_block_t threshold, + dm_sm_threshold_fn fn, + void *context) +{ + if (sm->register_threshold_callback) + return sm->register_threshold_callback(sm, threshold, fn, context); + + return -EINVAL; +} + + #endif /* _LINUX_DM_SPACE_MAP_H */ |