1/*
  2 * Copyright (C) 2012 Red Hat. All rights reserved.
  3 *
  4 * This file is released under the GPL.
  5 */
  6
  7#ifndef DM_CACHE_POLICY_INTERNAL_H
  8#define DM_CACHE_POLICY_INTERNAL_H
  9
 10#include "dm-cache-policy.h"
 11
 12/*----------------------------------------------------------------*/
 13
 14/*
 15 * Little inline functions that simplify calling the policy methods.
 16 */
 17static inline int policy_map(struct dm_cache_policy *p, dm_oblock_t oblock,
 18			     bool can_block, bool can_migrate, bool discarded_oblock,
 19			     struct bio *bio, struct policy_result *result)
 20{
 21	return p->map(p, oblock, can_block, can_migrate, discarded_oblock, bio, result);
 22}
 23
 24static inline int policy_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock)
 25{
 26	BUG_ON(!p->lookup);
 27	return p->lookup(p, oblock, cblock);
 28}
 29
 30static inline void policy_set_dirty(struct dm_cache_policy *p, dm_oblock_t oblock)
 31{
 32	if (p->set_dirty)
 33		p->set_dirty(p, oblock);
 34}
 35
 36static inline void policy_clear_dirty(struct dm_cache_policy *p, dm_oblock_t oblock)
 37{
 38	if (p->clear_dirty)
 39		p->clear_dirty(p, oblock);
 40}
 41
 42static inline int policy_load_mapping(struct dm_cache_policy *p,
 43				      dm_oblock_t oblock, dm_cblock_t cblock,
 44				      uint32_t hint, bool hint_valid)
 45{
 46	return p->load_mapping(p, oblock, cblock, hint, hint_valid);
 47}
 48
 49static inline int policy_walk_mappings(struct dm_cache_policy *p,
 50				      policy_walk_fn fn, void *context)
 51{
 52	return p->walk_mappings ? p->walk_mappings(p, fn, context) : 0;
 53}
 54
 55static inline int policy_writeback_work(struct dm_cache_policy *p,
 56					dm_oblock_t *oblock,
 57					dm_cblock_t *cblock)
 58{
 59	return p->writeback_work ? p->writeback_work(p, oblock, cblock) : -ENOENT;
 60}
 61
 62static inline void policy_remove_mapping(struct dm_cache_policy *p, dm_oblock_t oblock)
 63{
 64	p->remove_mapping(p, oblock);
 65}
 66
 67static inline int policy_remove_cblock(struct dm_cache_policy *p, dm_cblock_t cblock)
 68{
 69	return p->remove_cblock(p, cblock);
 70}
 71
 72static inline void policy_force_mapping(struct dm_cache_policy *p,
 73					dm_oblock_t current_oblock, dm_oblock_t new_oblock)
 74{
 75	return p->force_mapping(p, current_oblock, new_oblock);
 76}
 77
 78static inline dm_cblock_t policy_residency(struct dm_cache_policy *p)
 79{
 80	return p->residency(p);
 81}
 82
 83static inline void policy_tick(struct dm_cache_policy *p)
 84{
 85	if (p->tick)
 86		return p->tick(p);
 87}
 88
 89static inline int policy_emit_config_values(struct dm_cache_policy *p, char *result, unsigned maxlen)
 90{
 91	ssize_t sz = 0;
 92	if (p->emit_config_values)
 93		return p->emit_config_values(p, result, maxlen);
 94
 95	DMEMIT("0");
 96	return 0;
 97}
 98
 99static inline int policy_set_config_value(struct dm_cache_policy *p,
100					  const char *key, const char *value)
101{
102	return p->set_config_value ? p->set_config_value(p, key, value) : -EINVAL;
103}
104
105/*----------------------------------------------------------------*/
106
107/*
108 * Creates a new cache policy given a policy name, a cache size, an origin size and the block size.
109 */
110struct dm_cache_policy *dm_cache_policy_create(const char *name, dm_cblock_t cache_size,
111					       sector_t origin_size, sector_t block_size);
112
113/*
114 * Destroys the policy.  This drops references to the policy module as well
115 * as calling it's destroy method.  So always use this rather than calling
116 * the policy->destroy method directly.
117 */
118void dm_cache_policy_destroy(struct dm_cache_policy *p);
119
120/*
121 * In case we've forgotten.
122 */
123const char *dm_cache_policy_get_name(struct dm_cache_policy *p);
124
125const unsigned *dm_cache_policy_get_version(struct dm_cache_policy *p);
126
127size_t dm_cache_policy_get_hint_size(struct dm_cache_policy *p);
128
129/*----------------------------------------------------------------*/
130
131#endif /* DM_CACHE_POLICY_INTERNAL_H */