21  * identifies a cache entry.
24  * and a special "delete entry with given key-value pair" operation. Fixed
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.
77 	struct mb_cache_entry *entry, *dup;  in mb_cache_entry_create()  local
88 	entry = kmem_cache_alloc(mb_entry_cache, mask);  in mb_cache_entry_create()
89 	if (!entry)  in mb_cache_entry_create()
92 	INIT_LIST_HEAD(&entry->e_list);  in mb_cache_entry_create()
94 	atomic_set(&entry->e_refcnt, 1);  in mb_cache_entry_create()
95 	entry->e_key = key;  in mb_cache_entry_create()
96 	entry->e_value = value;  in mb_cache_entry_create()
97 	entry->e_reusable = reusable;  in mb_cache_entry_create()
98 	entry->e_referenced = 0;  in mb_cache_entry_create()
104 			kmem_cache_free(mb_entry_cache, entry);  in mb_cache_entry_create()
108 	hlist_bl_add_head(&entry->e_hash_list, head);  in mb_cache_entry_create()
112 	list_add_tail(&entry->e_list, &cache->c_list);  in mb_cache_entry_create()
114 	atomic_inc(&entry->e_refcnt);  in mb_cache_entry_create()
122 void __mb_cache_entry_free(struct mb_cache_entry *entry)  in __mb_cache_entry_free()  argument
124 	kmem_cache_free(mb_entry_cache, entry);  in __mb_cache_entry_free()
129 					   struct mb_cache_entry *entry,  in __entry_find()  argument
132 	struct mb_cache_entry *old_entry = entry;  in __entry_find()
138 	if (entry && !hlist_bl_unhashed(&entry->e_hash_list))  in __entry_find()
139 		node = entry->e_hash_list.next;  in __entry_find()
143 		entry = hlist_bl_entry(node, struct mb_cache_entry,  in __entry_find()
145 		if (entry->e_key == key && entry->e_reusable) {  in __entry_find()
146 			atomic_inc(&entry->e_refcnt);  in __entry_find()
151 	entry = NULL;  in __entry_find()
157 	return entry;  in __entry_find()
161  * mb_cache_entry_find_first - find the first reusable entry with the given key
165  * Search in @cache for a reusable entry with key @key. Grabs reference to the
166  * first reusable entry found and returns the entry.
176  * mb_cache_entry_find_next - find next reusable entry with the same key
178  * @entry: entry to start search from
180  * Finds next reusable entry in the hash chain which has the same key as @entry.
181  * If @entry is unhashed (which can happen when deletion of entry races with the
182  * search), finds the first reusable entry in the hash chain. The function drops
183  * reference to @entry and returns with a reference to the found entry.
186 						struct mb_cache_entry *entry)  in mb_cache_entry_find_next()  argument
188 	return __entry_find(cache, entry, entry->e_key);  in mb_cache_entry_find_next()
193  * mb_cache_entry_get - get a cache entry by value (and key)
203 	struct mb_cache_entry *entry;  in mb_cache_entry_get()  local
207 	hlist_bl_for_each_entry(entry, node, head, e_hash_list) {  in mb_cache_entry_get()
208 		if (entry->e_key == key && entry->e_value == value) {  in mb_cache_entry_get()
209 			atomic_inc(&entry->e_refcnt);  in mb_cache_entry_get()
213 	entry = NULL;  in mb_cache_entry_get()
216 	return entry;  in mb_cache_entry_get()
220 /* mb_cache_entry_delete - remove a cache entry
225  * Remove entry from cache @cache with key @key and value @value.
231 	struct mb_cache_entry *entry;  in mb_cache_entry_delete()  local
235 	hlist_bl_for_each_entry(entry, node, head, e_hash_list) {  in mb_cache_entry_delete()
236 		if (entry->e_key == key && entry->e_value == value) {  in mb_cache_entry_delete()
237 			/* We keep hash list reference to keep entry alive */  in mb_cache_entry_delete()
238 			hlist_bl_del_init(&entry->e_hash_list);  in mb_cache_entry_delete()
241 			if (!list_empty(&entry->e_list)) {  in mb_cache_entry_delete()
242 				list_del_init(&entry->e_list);  in mb_cache_entry_delete()
246 				atomic_dec(&entry->e_refcnt);  in mb_cache_entry_delete()
249 			mb_cache_entry_put(cache, entry);  in mb_cache_entry_delete()
257 /* mb_cache_entry_touch - cache entry got used
258  * @cache - cache the entry belongs to
259  * @entry - entry that got used
261  * Marks entry as used to give hit higher chances of surviving in cache.
264 			  struct mb_cache_entry *entry)  in mb_cache_entry_touch()  argument
266 	entry->e_referenced = 1;  in mb_cache_entry_touch()
283 	struct mb_cache_entry *entry;  in mb_cache_shrink()  local
289 		entry = list_first_entry(&cache->c_list,  in mb_cache_shrink()
291 		if (entry->e_referenced) {  in mb_cache_shrink()
292 			entry->e_referenced = 0;  in mb_cache_shrink()
293 			list_move_tail(&entry->e_list, &cache->c_list);  in mb_cache_shrink()
296 		list_del_init(&entry->e_list);  in mb_cache_shrink()
299 		 * We keep LRU list reference so that entry doesn't go away  in mb_cache_shrink()
303 		head = mb_cache_entry_head(cache, entry->e_key);  in mb_cache_shrink()
305 		if (!hlist_bl_unhashed(&entry->e_hash_list)) {  in mb_cache_shrink()
306 			hlist_bl_del_init(&entry->e_hash_list);  in mb_cache_shrink()
307 			atomic_dec(&entry->e_refcnt);  in mb_cache_shrink()
310 		if (mb_cache_entry_put(cache, entry))  in mb_cache_shrink()
394 	struct mb_cache_entry *entry, *next;  in mb_cache_destroy()  local
402 	list_for_each_entry_safe(entry, next, &cache->c_list, e_list) {  in mb_cache_destroy()
403 		if (!hlist_bl_unhashed(&entry->e_hash_list)) {  in mb_cache_destroy()
404 			hlist_bl_del_init(&entry->e_hash_list);  in mb_cache_destroy()
405 			atomic_dec(&entry->e_refcnt);  in mb_cache_destroy()
408 		list_del(&entry->e_list);  in mb_cache_destroy()
409 		WARN_ON(atomic_read(&entry->e_refcnt) != 1);  in mb_cache_destroy()
410 		mb_cache_entry_put(cache, entry);  in mb_cache_destroy()