include/linux/mbcache.h

   1 /*
   2   File: linux/mbcache.h
   3
   4   (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
   5 */
   6 struct mb_cache_entry {
   7         struct list_head                e_lru_list;
   8         struct mb_cache                 *e_cache;
   9         unsigned short                  e_used;
  10         unsigned short                  e_queued;
  11         atomic_t                        e_refcnt;
  12         struct block_device             *e_bdev;
  13         sector_t                        e_block;
  14         struct hlist_bl_node            e_block_list;
  15         struct {
  16                 struct hlist_bl_node    o_list;
  17                 unsigned int            o_key;
  18         } e_index;
  19         struct hlist_bl_head            *e_block_hash_p;
  20         struct hlist_bl_head            *e_index_hash_p;
  21 };
  22
  23 struct mb_cache {
  24         struct list_head                c_cache_list;
  25         const char                      *c_name;
  26         atomic_t                        c_entry_count;
  27         int                             c_max_entries;
  28         int                             c_bucket_bits;
  29         struct kmem_cache               *c_entry_cache;
  30         struct hlist_bl_head            *c_block_hash;
  31         struct hlist_bl_head            *c_index_hash;
  32 };
  33
  34 /* Functions on caches */
  35
  36 struct mb_cache *mb_cache_create(const char *, int);
  37 void mb_cache_shrink(struct block_device *);
  38 void mb_cache_destroy(struct mb_cache *);
  39
  40 /* Functions on cache entries */
  41
  42 struct mb_cache_entry *mb_cache_entry_alloc(struct mb_cache *, gfp_t);
  43 int mb_cache_entry_insert(struct mb_cache_entry *, struct block_device *,
  44                           sector_t, unsigned int);
  45 void mb_cache_entry_release(struct mb_cache_entry *);
  46 void mb_cache_entry_free(struct mb_cache_entry *);
  47 struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *,
  48                                           struct block_device *,
  49                                           sector_t);
  50 struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache,
  51                                                  struct block_device *,
  52                                                  unsigned int);
  53 struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache_entry *,
  54                                                 struct block_device *,
  55                                                 unsigned int);