drivers/md/dm-cache-policy-internal.h

   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  */
  17 static 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
  24 static 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
  30 static 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
  36 static 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
  42 static 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
  49 static 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
  55 static 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
  62 static inline void policy_remove_mapping(struct dm_cache_policy *p, dm_oblock_t oblock)
  63 {
  64         return p->remove_mapping(p, oblock);
  65 }
  66
  67 static inline void policy_force_mapping(struct dm_cache_policy *p,
  68                                         dm_oblock_t current_oblock, dm_oblock_t new_oblock)
  69 {
  70         return p->force_mapping(p, current_oblock, new_oblock);
  71 }
  72
  73 static inline dm_cblock_t policy_residency(struct dm_cache_policy *p)
  74 {
  75         return p->residency(p);
  76 }
  77
  78 static inline void policy_tick(struct dm_cache_policy *p)
  79 {
  80         if (p->tick)
  81                 return p->tick(p);
  82 }
  83
  84 static inline int policy_emit_config_values(struct dm_cache_policy *p, char *result, unsigned maxlen)
  85 {
  86         ssize_t sz = 0;
  87         if (p->emit_config_values)
  88                 return p->emit_config_values(p, result, maxlen);
  89
  90         DMEMIT("0");
  91         return 0;
  92 }
  93
  94 static inline int policy_set_config_value(struct dm_cache_policy *p,
  95                                           const char *key, const char *value)
  96 {
  97         return p->set_config_value ? p->set_config_value(p, key, value) : -EINVAL;
  98 }
  99
 100 /*----------------------------------------------------------------*/
 101
 102 /*
 103  * Creates a new cache policy given a policy name, a cache size, an origin size and the block size.
 104  */
 105 struct dm_cache_policy *dm_cache_policy_create(const char *name, dm_cblock_t cache_size,
 106                                                sector_t origin_size, sector_t block_size);
 107
 108 /*
 109  * Destroys the policy.  This drops references to the policy module as well
 110  * as calling it's destroy method.  So always use this rather than calling
 111  * the policy->destroy method directly.
 112  */
 113 void dm_cache_policy_destroy(struct dm_cache_policy *p);
 114
 115 /*
 116  * In case we've forgotten.
 117  */
 118 const char *dm_cache_policy_get_name(struct dm_cache_policy *p);
 119
 120 const unsigned *dm_cache_policy_get_version(struct dm_cache_policy *p);
 121
 122 size_t dm_cache_policy_get_hint_size(struct dm_cache_policy *p);
 123
 124 /*----------------------------------------------------------------*/
 125
 126 #endif /* DM_CACHE_POLICY_INTERNAL_H */