include/linux/mbcache.h

   1 #ifndef _LINUX_MBCACHE_H
   2 #define _LINUX_MBCACHE_H
   3
   4 #include <linux/hash.h>
   5 #include <linux/list_bl.h>
   6 #include <linux/list.h>
   7 #include <linux/atomic.h>
   8 #include <linux/fs.h>
   9
  10 struct mb_cache;
  11
  12 struct mb_cache_entry {
  13         /* List of entries in cache - protected by cache->c_list_lock */
  14         struct list_head        e_list;
  15         /* Hash table list - protected by hash chain bitlock */
  16         struct hlist_bl_node    e_hash_list;
  17         atomic_t                e_refcnt;
  18         /* Key in hash - stable during lifetime of the entry */
  19         u32                     e_key;
  20         u32                     e_referenced:1;
  21         u32                     e_reusable:1;
  22         /* Block number of hashed block - stable during lifetime of the entry */
  23         sector_t                e_block;
  24 };
  25
  26 struct mb_cache *mb_cache_create(int bucket_bits);
  27 void mb_cache_destroy(struct mb_cache *cache);
  28
  29 int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key,
  30                           sector_t block, bool reusable);
  31 void __mb_cache_entry_free(struct mb_cache_entry *entry);
  32 static inline int mb_cache_entry_put(struct mb_cache *cache,
  33                                      struct mb_cache_entry *entry)
  34 {
  35         if (!atomic_dec_and_test(&entry->e_refcnt))
  36                 return 0;
  37         __mb_cache_entry_free(entry);
  38         return 1;
  39 }
  40
  41 void mb_cache_entry_delete_block(struct mb_cache *cache, u32 key,
  42                                   sector_t block);
  43 struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
  44                                           sector_t block);
  45 struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache,
  46                                                  u32 key);
  47 struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache,
  48                                                 struct mb_cache_entry *entry);
  49 void mb_cache_entry_touch(struct mb_cache *cache,
  50                           struct mb_cache_entry *entry);
  51
  52 #endif  /* _LINUX_MBCACHE_H */