| /* |
| * Copyright (C) 2012 Red Hat, Inc. |
| * |
| * This file is released under the GPL. |
| */ |
| |
| #ifndef DM_CACHE_METADATA_H |
| #define DM_CACHE_METADATA_H |
| |
| #include "dm-cache-block-types.h" |
| #include "dm-cache-policy-internal.h" |
| #include "persistent-data/dm-space-map-metadata.h" |
| |
| /*----------------------------------------------------------------*/ |
| |
| #define DM_CACHE_METADATA_BLOCK_SIZE DM_SM_METADATA_BLOCK_SIZE |
| |
| /* FIXME: remove this restriction */ |
| /* |
| * The metadata device is currently limited in size. |
| */ |
| #define DM_CACHE_METADATA_MAX_SECTORS DM_SM_METADATA_MAX_SECTORS |
| |
| /* |
| * A metadata device larger than 16GB triggers a warning. |
| */ |
| #define DM_CACHE_METADATA_MAX_SECTORS_WARNING (16 * (1024 * 1024 * 1024 >> SECTOR_SHIFT)) |
| |
| /*----------------------------------------------------------------*/ |
| |
| /* |
| * Ext[234]-style compat feature flags. |
| * |
| * A new feature which old metadata will still be compatible with should |
| * define a DM_CACHE_FEATURE_COMPAT_* flag (rarely useful). |
| * |
| * A new feature that is not compatible with old code should define a |
| * DM_CACHE_FEATURE_INCOMPAT_* flag and guard the relevant code with |
| * that flag. |
| * |
| * A new feature that is not compatible with old code accessing the |
| * metadata RDWR should define a DM_CACHE_FEATURE_RO_COMPAT_* flag and |
| * guard the relevant code with that flag. |
| * |
| * As these various flags are defined they should be added to the |
| * following masks. |
| */ |
| #define DM_CACHE_FEATURE_COMPAT_SUPP 0UL |
| #define DM_CACHE_FEATURE_COMPAT_RO_SUPP 0UL |
| #define DM_CACHE_FEATURE_INCOMPAT_SUPP 0UL |
| |
| /* |
| * Reopens or creates a new, empty metadata volume. |
| * Returns an ERR_PTR on failure. |
| */ |
| struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev, |
| sector_t data_block_size, |
| bool may_format_device, |
| size_t policy_hint_size); |
| |
| void dm_cache_metadata_close(struct dm_cache_metadata *cmd); |
| |
| /* |
| * The metadata needs to know how many cache blocks there are. We don't |
| * care about the origin, assuming the core target is giving us valid |
| * origin blocks to map to. |
| */ |
| int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size); |
| int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result); |
| |
| int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd, |
| sector_t discard_block_size, |
| dm_dblock_t new_nr_entries); |
| |
| typedef int (*load_discard_fn)(void *context, sector_t discard_block_size, |
| dm_dblock_t dblock, bool discarded); |
| int dm_cache_load_discards(struct dm_cache_metadata *cmd, |
| load_discard_fn fn, void *context); |
| |
| int dm_cache_set_discard(struct dm_cache_metadata *cmd, dm_dblock_t dblock, bool discard); |
| |
| int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock); |
| int dm_cache_insert_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock, dm_oblock_t oblock); |
| int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd); |
| |
| typedef int (*load_mapping_fn)(void *context, dm_oblock_t oblock, |
| dm_cblock_t cblock, bool dirty, |
| uint32_t hint, bool hint_valid); |
| int dm_cache_load_mappings(struct dm_cache_metadata *cmd, |
| struct dm_cache_policy *policy, |
| load_mapping_fn fn, |
| void *context); |
| |
| int dm_cache_set_dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty); |
| |
| struct dm_cache_statistics { |
| uint32_t read_hits; |
| uint32_t read_misses; |
| uint32_t write_hits; |
| uint32_t write_misses; |
| }; |
| |
| void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd, |
| struct dm_cache_statistics *stats); |
| |
| /* |
| * 'void' because it's no big deal if it fails. |
| */ |
| void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd, |
| struct dm_cache_statistics *stats); |
| |
| int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown); |
| |
| int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd, |
| dm_block_t *result); |
| |
| int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd, |
| dm_block_t *result); |
| |
| void dm_cache_dump(struct dm_cache_metadata *cmd); |
| |
| /* |
| * The policy is invited to save a 32bit hint value for every cblock (eg, |
| * for a hit count). These are stored against the policy name. If |
| * policies are changed, then hints will be lost. If the machine crashes, |
| * hints will be lost. |
| * |
| * The hints are indexed by the cblock, but many policies will not |
| * neccessarily have a fast way of accessing efficiently via cblock. So |
| * rather than querying the policy for each cblock, we let it walk its data |
| * structures and fill in the hints in whatever order it wishes. |
| */ |
| int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *p); |
| |
| /* |
| * Query method. Are all the blocks in the cache clean? |
| */ |
| int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result); |
| |
| int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result); |
| int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd); |
| void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd); |
| void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd); |
| int dm_cache_metadata_abort(struct dm_cache_metadata *cmd); |
| |
| /*----------------------------------------------------------------*/ |
| |
| #endif /* DM_CACHE_METADATA_H */ |