Lines Matching +full:key +full:- +full:value
1 // SPDX-License-Identifier: GPL-2.0-only
12 * Mbcache is a simple key-value store. Keys need not be unique, however
13 * key-value pairs are expected to be unique (we use this fact in
18 * They use hash of data as a key and provide a value that may represent a
20 * data may be the same). However user provided value always uniquely
23 * We provide functions for creation and removal of entries, search by key,
24 * and a special "delete entry with given key-value pair" operation. Fixed
25 * size hash table is used for fast key lookups.
51 u32 key) in mb_cache_entry_head() argument
53 return &cache->c_hash[hash_32(key, cache->c_bucket_bits)]; in mb_cache_entry_head()
63 * mb_cache_entry_create - create entry in cache
64 * @cache - cache where the entry should be created
65 * @mask - gfp mask with which the entry should be allocated
66 * @key - key of the entry
67 * @value - value of the entry
68 * @reusable - is the entry reusable by others?
70 * Creates entry in @cache with key @key and value @value. The function returns
71 * -EBUSY if entry with the same key and value already exists in cache.
74 int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key, in mb_cache_entry_create() argument
75 u64 value, bool reusable) in mb_cache_entry_create() argument
82 if (cache->c_entry_count >= cache->c_max_entries) in mb_cache_entry_create()
83 schedule_work(&cache->c_shrink_work); in mb_cache_entry_create()
85 if (cache->c_entry_count >= 2*cache->c_max_entries) in mb_cache_entry_create()
90 return -ENOMEM; in mb_cache_entry_create()
92 INIT_LIST_HEAD(&entry->e_list); in mb_cache_entry_create()
97 * avoids nesting of cache->c_list_lock into hash table bit locks which in mb_cache_entry_create()
100 atomic_set(&entry->e_refcnt, 2); in mb_cache_entry_create()
101 entry->e_key = key; in mb_cache_entry_create()
102 entry->e_value = value; in mb_cache_entry_create()
103 entry->e_flags = 0; in mb_cache_entry_create()
105 set_bit(MBE_REUSABLE_B, &entry->e_flags); in mb_cache_entry_create()
106 head = mb_cache_entry_head(cache, key); in mb_cache_entry_create()
109 if (dup->e_key == key && dup->e_value == value) { in mb_cache_entry_create()
112 return -EBUSY; in mb_cache_entry_create()
115 hlist_bl_add_head(&entry->e_hash_list, head); in mb_cache_entry_create()
117 spin_lock(&cache->c_list_lock); in mb_cache_entry_create()
118 list_add_tail(&entry->e_list, &cache->c_list); in mb_cache_entry_create()
119 cache->c_entry_count++; in mb_cache_entry_create()
120 spin_unlock(&cache->c_list_lock); in mb_cache_entry_create()
131 head = mb_cache_entry_head(cache, entry->e_key); in __mb_cache_entry_free()
133 hlist_bl_del(&entry->e_hash_list); in __mb_cache_entry_free()
140 * mb_cache_entry_wait_unused - wait to be the last user of the entry
142 * @entry - entry to work on
148 wait_var_event(&entry->e_refcnt, atomic_read(&entry->e_refcnt) <= 2); in mb_cache_entry_wait_unused()
154 u32 key) in __entry_find() argument
160 head = mb_cache_entry_head(cache, key); in __entry_find()
162 if (entry && !hlist_bl_unhashed(&entry->e_hash_list)) in __entry_find()
163 node = entry->e_hash_list.next; in __entry_find()
169 if (entry->e_key == key && in __entry_find()
170 test_bit(MBE_REUSABLE_B, &entry->e_flags) && in __entry_find()
171 atomic_inc_not_zero(&entry->e_refcnt)) in __entry_find()
173 node = node->next; in __entry_find()
185 * mb_cache_entry_find_first - find the first reusable entry with the given key
187 * @key: key to look for
189 * Search in @cache for a reusable entry with key @key. Grabs reference to the
193 u32 key) in mb_cache_entry_find_first() argument
195 return __entry_find(cache, NULL, key); in mb_cache_entry_find_first()
200 * mb_cache_entry_find_next - find next reusable entry with the same key
204 * Finds next reusable entry in the hash chain which has the same key as @entry.
212 return __entry_find(cache, entry, entry->e_key); in mb_cache_entry_find_next()
217 * mb_cache_entry_get - get a cache entry by value (and key)
218 * @cache - cache we work with
219 * @key - key
220 * @value - value
222 struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key, in mb_cache_entry_get() argument
223 u64 value) in mb_cache_entry_get() argument
229 head = mb_cache_entry_head(cache, key); in mb_cache_entry_get()
232 if (entry->e_key == key && entry->e_value == value && in mb_cache_entry_get()
233 atomic_inc_not_zero(&entry->e_refcnt)) in mb_cache_entry_get()
243 /* mb_cache_entry_delete_or_get - remove a cache entry if it has no users
244 * @cache - cache we work with
245 * @key - key
246 * @value - value
248 * Remove entry from cache @cache with key @key and value @value. The removal
255 u32 key, u64 value) in mb_cache_entry_delete_or_get() argument
259 entry = mb_cache_entry_get(cache, key, value); in mb_cache_entry_delete_or_get()
267 if (atomic_cmpxchg(&entry->e_refcnt, 2, 0) != 2) in mb_cache_entry_delete_or_get()
270 spin_lock(&cache->c_list_lock); in mb_cache_entry_delete_or_get()
271 if (!list_empty(&entry->e_list)) in mb_cache_entry_delete_or_get()
272 list_del_init(&entry->e_list); in mb_cache_entry_delete_or_get()
273 cache->c_entry_count--; in mb_cache_entry_delete_or_get()
274 spin_unlock(&cache->c_list_lock); in mb_cache_entry_delete_or_get()
280 /* mb_cache_entry_touch - cache entry got used
281 * @cache - cache the entry belongs to
282 * @entry - entry that got used
289 set_bit(MBE_REFERENCED_B, &entry->e_flags); in mb_cache_entry_touch()
296 struct mb_cache *cache = shrink->private_data; in mb_cache_count()
298 return cache->c_entry_count; in mb_cache_count()
308 spin_lock(&cache->c_list_lock); in mb_cache_shrink()
309 while (nr_to_scan-- && !list_empty(&cache->c_list)) { in mb_cache_shrink()
310 entry = list_first_entry(&cache->c_list, in mb_cache_shrink()
313 if (test_bit(MBE_REFERENCED_B, &entry->e_flags) || in mb_cache_shrink()
314 atomic_cmpxchg(&entry->e_refcnt, 1, 0) != 1) { in mb_cache_shrink()
315 clear_bit(MBE_REFERENCED_B, &entry->e_flags); in mb_cache_shrink()
316 list_move_tail(&entry->e_list, &cache->c_list); in mb_cache_shrink()
319 list_del_init(&entry->e_list); in mb_cache_shrink()
320 cache->c_entry_count--; in mb_cache_shrink()
321 spin_unlock(&cache->c_list_lock); in mb_cache_shrink()
325 spin_lock(&cache->c_list_lock); in mb_cache_shrink()
327 spin_unlock(&cache->c_list_lock); in mb_cache_shrink()
335 struct mb_cache *cache = shrink->private_data; in mb_cache_scan()
336 return mb_cache_shrink(cache, sc->nr_to_scan); in mb_cache_scan()
346 mb_cache_shrink(cache, cache->c_max_entries / SHRINK_DIVISOR); in mb_cache_shrink_worker()
350 * mb_cache_create - create cache
364 cache->c_bucket_bits = bucket_bits; in mb_cache_create()
365 cache->c_max_entries = bucket_count << 4; in mb_cache_create()
366 INIT_LIST_HEAD(&cache->c_list); in mb_cache_create()
367 spin_lock_init(&cache->c_list_lock); in mb_cache_create()
368 cache->c_hash = kmalloc_array(bucket_count, in mb_cache_create()
371 if (!cache->c_hash) { in mb_cache_create()
376 INIT_HLIST_BL_HEAD(&cache->c_hash[i]); in mb_cache_create()
378 cache->c_shrink = shrinker_alloc(0, "mbcache-shrinker"); in mb_cache_create()
379 if (!cache->c_shrink) { in mb_cache_create()
380 kfree(cache->c_hash); in mb_cache_create()
385 cache->c_shrink->count_objects = mb_cache_count; in mb_cache_create()
386 cache->c_shrink->scan_objects = mb_cache_scan; in mb_cache_create()
387 cache->c_shrink->private_data = cache; in mb_cache_create()
389 shrinker_register(cache->c_shrink); in mb_cache_create()
391 INIT_WORK(&cache->c_shrink_work, mb_cache_shrink_worker); in mb_cache_create()
401 * mb_cache_destroy - destroy cache
411 shrinker_free(cache->c_shrink); in mb_cache_destroy()
417 list_for_each_entry_safe(entry, next, &cache->c_list, e_list) { in mb_cache_destroy()
418 list_del(&entry->e_list); in mb_cache_destroy()
419 WARN_ON(atomic_read(&entry->e_refcnt) != 1); in mb_cache_destroy()
422 kfree(cache->c_hash); in mb_cache_destroy()
431 return -ENOMEM; in mbcache_init()