LXR linux/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
  10struct mb_cache;
  11
  12struct 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
  26struct mb_cache *mb_cache_create(int bucket_bits);
  27void mb_cache_destroy(struct mb_cache *cache);
  28
  29int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key,
  30                          sector_t block, bool reusable);
  31void __mb_cache_entry_free(struct mb_cache_entry *entry);
  32static 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
  41void mb_cache_entry_delete_block(struct mb_cache *cache, u32 key,
  42                                  sector_t block);
  43struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
  44                                          sector_t block);
  45struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache,
  46                                                 u32 key);
  47struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache,
  48                                                struct mb_cache_entry *entry);
  49void mb_cache_entry_touch(struct mb_cache *cache,
  50                          struct mb_cache_entry *entry);
  51
  52#endif  /* _LINUX_MBCACHE_H */
  53