include/linux/mbcache.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_MBCACHE_H
   3 #define _LINUX_MBCACHE_H
   4
   5 #include <linux/hash.h>
   6 #include <linux/list_bl.h>
   7 #include <linux/list.h>
   8 #include <linux/atomic.h>
   9 #include <linux/fs.h>
  10
  11 struct mb_cache;
  12
  13 struct mb_cache_entry {
  14         /* List of entries in cache - protected by cache->c_list_lock */
  15         struct list_head        e_list;
  16         /* Hash table list - protected by hash chain bitlock */
  17         struct hlist_bl_node    e_hash_list;
  18         atomic_t                e_refcnt;
  19         /* Key in hash - stable during lifetime of the entry */
  20         u32                     e_key;
  21         u32                     e_referenced:1;
  22         u32                     e_reusable:1;
  23         /* User provided value - stable during lifetime of the entry */
  24         u64                     e_value;
  25 };
  26
  27 struct mb_cache *mb_cache_create(int bucket_bits);
  28 void mb_cache_destroy(struct mb_cache *cache);
  29
  30 int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key,
  31                           u64 value, bool reusable);
  32 void __mb_cache_entry_free(struct mb_cache_entry *entry);
  33 static inline int mb_cache_entry_put(struct mb_cache *cache,
  34                                      struct mb_cache_entry *entry)
  35 {
  36         if (!atomic_dec_and_test(&entry->e_refcnt))
  37                 return 0;
  38         __mb_cache_entry_free(entry);
  39         return 1;
  40 }
  41
  42 void mb_cache_entry_delete(struct mb_cache *cache, u32 key, u64 value);
  43 struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
  44                                           u64 value);
  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 */