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1/* SPDX-License-Identifier: GPL-2.0-only */2/*3 * Copyright (C) 2012 Red Hat, Inc.4 *5 * This file is released under the GPL.6 */7 8#ifndef DM_CACHE_METADATA_H9#define DM_CACHE_METADATA_H10 11#include "dm-cache-block-types.h"12#include "dm-cache-policy-internal.h"13#include "persistent-data/dm-space-map-metadata.h"14 15/*----------------------------------------------------------------*/16 17#define DM_CACHE_METADATA_BLOCK_SIZE DM_SM_METADATA_BLOCK_SIZE18 19/* FIXME: remove this restriction */20/*21 * The metadata device is currently limited in size.22 */23#define DM_CACHE_METADATA_MAX_SECTORS DM_SM_METADATA_MAX_SECTORS24 25/*26 * A metadata device larger than 16GB triggers a warning.27 */28#define DM_CACHE_METADATA_MAX_SECTORS_WARNING (16 * (1024 * 1024 * 1024 >> SECTOR_SHIFT))29 30/*----------------------------------------------------------------*/31 32/*33 * Ext[234]-style compat feature flags.34 *35 * A new feature which old metadata will still be compatible with should36 * define a DM_CACHE_FEATURE_COMPAT_* flag (rarely useful).37 *38 * A new feature that is not compatible with old code should define a39 * DM_CACHE_FEATURE_INCOMPAT_* flag and guard the relevant code with40 * that flag.41 *42 * A new feature that is not compatible with old code accessing the43 * metadata RDWR should define a DM_CACHE_FEATURE_RO_COMPAT_* flag and44 * guard the relevant code with that flag.45 *46 * As these various flags are defined they should be added to the47 * following masks.48 */49 50#define DM_CACHE_FEATURE_COMPAT_SUPP 0UL51#define DM_CACHE_FEATURE_COMPAT_RO_SUPP 0UL52#define DM_CACHE_FEATURE_INCOMPAT_SUPP 0UL53 54struct dm_cache_metadata;55 56/*57 * Reopens or creates a new, empty metadata volume. Returns an ERR_PTR on58 * failure. If reopening then features must match.59 */60struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,61 sector_t data_block_size,62 bool may_format_device,63 size_t policy_hint_size,64 unsigned int metadata_version);65 66void dm_cache_metadata_close(struct dm_cache_metadata *cmd);67 68/*69 * The metadata needs to know how many cache blocks there are. We don't70 * care about the origin, assuming the core target is giving us valid71 * origin blocks to map to.72 */73int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size);74int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result);75 76int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,77 sector_t discard_block_size,78 dm_dblock_t new_nr_entries);79 80typedef int (*load_discard_fn)(void *context, sector_t discard_block_size,81 dm_dblock_t dblock, bool discarded);82int dm_cache_load_discards(struct dm_cache_metadata *cmd,83 load_discard_fn fn, void *context);84 85int dm_cache_set_discard(struct dm_cache_metadata *cmd, dm_dblock_t dblock, bool discard);86 87int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock);88int dm_cache_insert_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock, dm_oblock_t oblock);89int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd);90 91typedef int (*load_mapping_fn)(void *context, dm_oblock_t oblock,92 dm_cblock_t cblock, bool dirty,93 uint32_t hint, bool hint_valid);94int dm_cache_load_mappings(struct dm_cache_metadata *cmd,95 struct dm_cache_policy *policy,96 load_mapping_fn fn,97 void *context);98 99int dm_cache_set_dirty_bits(struct dm_cache_metadata *cmd,100 unsigned int nr_bits, unsigned long *bits);101 102struct dm_cache_statistics {103 uint32_t read_hits;104 uint32_t read_misses;105 uint32_t write_hits;106 uint32_t write_misses;107};108 109void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,110 struct dm_cache_statistics *stats);111 112/*113 * 'void' because it's no big deal if it fails.114 */115void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,116 struct dm_cache_statistics *stats);117 118int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown);119 120int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,121 dm_block_t *result);122 123int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,124 dm_block_t *result);125 126void dm_cache_dump(struct dm_cache_metadata *cmd);127 128/*129 * The policy is invited to save a 32bit hint value for every cblock (eg,130 * for a hit count). These are stored against the policy name. If131 * policies are changed, then hints will be lost. If the machine crashes,132 * hints will be lost.133 *134 * The hints are indexed by the cblock, but many policies will not135 * necessarily have a fast way of accessing efficiently via cblock. So136 * rather than querying the policy for each cblock, we let it walk its data137 * structures and fill in the hints in whatever order it wishes.138 */139int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *p);140 141/*142 * Query method. Are all the blocks in the cache clean?143 */144int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result);145 146int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result);147int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd);148void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd);149void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd);150int dm_cache_metadata_abort(struct dm_cache_metadata *cmd);151 152/*----------------------------------------------------------------*/153 154#endif /* DM_CACHE_METADATA_H */155