Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
f9a61eb4 JK |
2 | #include <linux/spinlock.h> |
3 | #include <linux/slab.h> | |
4 | #include <linux/list.h> | |
5 | #include <linux/list_bl.h> | |
6 | #include <linux/module.h> | |
7 | #include <linux/sched.h> | |
c2f3140f | 8 | #include <linux/workqueue.h> |
7a2508e1 | 9 | #include <linux/mbcache.h> |
f9a61eb4 JK |
10 | |
11 | /* | |
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 | |
3dc96bba | 14 | * mb_cache_entry_delete_or_get()). |
f9a61eb4 JK |
15 | * |
16 | * Ext2 and ext4 use this cache for deduplication of extended attribute blocks. | |
dec214d0 TE |
17 | * Ext4 also uses it for deduplication of xattr values stored in inodes. |
18 | * They use hash of data as a key and provide a value that may represent a | |
19 | * block or inode number. That's why keys need not be unique (hash of different | |
20 | * data may be the same). However user provided value always uniquely | |
21 | * identifies a cache entry. | |
f9a61eb4 JK |
22 | * |
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. | |
26 | */ | |
27 | ||
7a2508e1 | 28 | struct mb_cache { |
f9a61eb4 JK |
29 | /* Hash table of entries */ |
30 | struct hlist_bl_head *c_hash; | |
31 | /* log2 of hash table size */ | |
32 | int c_bucket_bits; | |
c2f3140f | 33 | /* Maximum entries in cache to avoid degrading hash too much */ |
132d4e2d | 34 | unsigned long c_max_entries; |
f0c8b462 JK |
35 | /* Protects c_list, c_entry_count */ |
36 | spinlock_t c_list_lock; | |
37 | struct list_head c_list; | |
f9a61eb4 JK |
38 | /* Number of entries in cache */ |
39 | unsigned long c_entry_count; | |
40 | struct shrinker c_shrink; | |
c2f3140f JK |
41 | /* Work for shrinking when the cache has too many entries */ |
42 | struct work_struct c_shrink_work; | |
f9a61eb4 JK |
43 | }; |
44 | ||
7a2508e1 | 45 | static struct kmem_cache *mb_entry_cache; |
f9a61eb4 | 46 | |
7a2508e1 | 47 | static unsigned long mb_cache_shrink(struct mb_cache *cache, |
132d4e2d | 48 | unsigned long nr_to_scan); |
c2f3140f | 49 | |
dc8d5e56 AG |
50 | static inline struct hlist_bl_head *mb_cache_entry_head(struct mb_cache *cache, |
51 | u32 key) | |
f0c8b462 | 52 | { |
dc8d5e56 | 53 | return &cache->c_hash[hash_32(key, cache->c_bucket_bits)]; |
f0c8b462 JK |
54 | } |
55 | ||
c2f3140f JK |
56 | /* |
57 | * Number of entries to reclaim synchronously when there are too many entries | |
58 | * in cache | |
59 | */ | |
60 | #define SYNC_SHRINK_BATCH 64 | |
61 | ||
f9a61eb4 | 62 | /* |
7a2508e1 | 63 | * mb_cache_entry_create - create entry in cache |
f9a61eb4 JK |
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 | |
c07dfcb4 TE |
67 | * @value - value of the entry |
68 | * @reusable - is the entry reusable by others? | |
f9a61eb4 | 69 | * |
c07dfcb4 TE |
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. | |
72 | * Otherwise 0 is returned. | |
f9a61eb4 | 73 | */ |
7a2508e1 | 74 | int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key, |
c07dfcb4 | 75 | u64 value, bool reusable) |
f9a61eb4 | 76 | { |
7a2508e1 | 77 | struct mb_cache_entry *entry, *dup; |
f9a61eb4 JK |
78 | struct hlist_bl_node *dup_node; |
79 | struct hlist_bl_head *head; | |
80 | ||
c2f3140f JK |
81 | /* Schedule background reclaim if there are too many entries */ |
82 | if (cache->c_entry_count >= cache->c_max_entries) | |
83 | schedule_work(&cache->c_shrink_work); | |
84 | /* Do some sync reclaim if background reclaim cannot keep up */ | |
85 | if (cache->c_entry_count >= 2*cache->c_max_entries) | |
7a2508e1 | 86 | mb_cache_shrink(cache, SYNC_SHRINK_BATCH); |
c2f3140f | 87 | |
7a2508e1 | 88 | entry = kmem_cache_alloc(mb_entry_cache, mask); |
f9a61eb4 JK |
89 | if (!entry) |
90 | return -ENOMEM; | |
91 | ||
f0c8b462 | 92 | INIT_LIST_HEAD(&entry->e_list); |
f9a61eb4 JK |
93 | /* One ref for hash, one ref returned */ |
94 | atomic_set(&entry->e_refcnt, 1); | |
95 | entry->e_key = key; | |
c07dfcb4 | 96 | entry->e_value = value; |
6048c64b | 97 | entry->e_reusable = reusable; |
3876bbe2 | 98 | entry->e_referenced = 0; |
dc8d5e56 | 99 | head = mb_cache_entry_head(cache, key); |
f9a61eb4 JK |
100 | hlist_bl_lock(head); |
101 | hlist_bl_for_each_entry(dup, dup_node, head, e_hash_list) { | |
c07dfcb4 | 102 | if (dup->e_key == key && dup->e_value == value) { |
f9a61eb4 | 103 | hlist_bl_unlock(head); |
7a2508e1 | 104 | kmem_cache_free(mb_entry_cache, entry); |
f9a61eb4 JK |
105 | return -EBUSY; |
106 | } | |
107 | } | |
108 | hlist_bl_add_head(&entry->e_hash_list, head); | |
109 | hlist_bl_unlock(head); | |
110 | ||
f0c8b462 JK |
111 | spin_lock(&cache->c_list_lock); |
112 | list_add_tail(&entry->e_list, &cache->c_list); | |
f9a61eb4 JK |
113 | /* Grab ref for LRU list */ |
114 | atomic_inc(&entry->e_refcnt); | |
115 | cache->c_entry_count++; | |
f0c8b462 | 116 | spin_unlock(&cache->c_list_lock); |
f9a61eb4 JK |
117 | |
118 | return 0; | |
119 | } | |
7a2508e1 | 120 | EXPORT_SYMBOL(mb_cache_entry_create); |
f9a61eb4 | 121 | |
7a2508e1 | 122 | void __mb_cache_entry_free(struct mb_cache_entry *entry) |
f9a61eb4 | 123 | { |
7a2508e1 | 124 | kmem_cache_free(mb_entry_cache, entry); |
f9a61eb4 | 125 | } |
7a2508e1 | 126 | EXPORT_SYMBOL(__mb_cache_entry_free); |
f9a61eb4 | 127 | |
3dc96bba JK |
128 | /* |
129 | * mb_cache_entry_wait_unused - wait to be the last user of the entry | |
130 | * | |
131 | * @entry - entry to work on | |
132 | * | |
133 | * Wait to be the last user of the entry. | |
134 | */ | |
135 | void mb_cache_entry_wait_unused(struct mb_cache_entry *entry) | |
136 | { | |
137 | wait_var_event(&entry->e_refcnt, atomic_read(&entry->e_refcnt) <= 3); | |
138 | } | |
139 | EXPORT_SYMBOL(mb_cache_entry_wait_unused); | |
140 | ||
7a2508e1 JK |
141 | static struct mb_cache_entry *__entry_find(struct mb_cache *cache, |
142 | struct mb_cache_entry *entry, | |
143 | u32 key) | |
f9a61eb4 | 144 | { |
7a2508e1 | 145 | struct mb_cache_entry *old_entry = entry; |
f9a61eb4 JK |
146 | struct hlist_bl_node *node; |
147 | struct hlist_bl_head *head; | |
148 | ||
dc8d5e56 | 149 | head = mb_cache_entry_head(cache, key); |
f9a61eb4 JK |
150 | hlist_bl_lock(head); |
151 | if (entry && !hlist_bl_unhashed(&entry->e_hash_list)) | |
152 | node = entry->e_hash_list.next; | |
153 | else | |
154 | node = hlist_bl_first(head); | |
155 | while (node) { | |
7a2508e1 | 156 | entry = hlist_bl_entry(node, struct mb_cache_entry, |
f9a61eb4 | 157 | e_hash_list); |
6048c64b | 158 | if (entry->e_key == key && entry->e_reusable) { |
f9a61eb4 JK |
159 | atomic_inc(&entry->e_refcnt); |
160 | goto out; | |
161 | } | |
162 | node = node->next; | |
163 | } | |
164 | entry = NULL; | |
165 | out: | |
166 | hlist_bl_unlock(head); | |
167 | if (old_entry) | |
7a2508e1 | 168 | mb_cache_entry_put(cache, old_entry); |
f9a61eb4 JK |
169 | |
170 | return entry; | |
171 | } | |
172 | ||
173 | /* | |
b649668c | 174 | * mb_cache_entry_find_first - find the first reusable entry with the given key |
f9a61eb4 JK |
175 | * @cache: cache where we should search |
176 | * @key: key to look for | |
177 | * | |
b649668c EB |
178 | * Search in @cache for a reusable entry with key @key. Grabs reference to the |
179 | * first reusable entry found and returns the entry. | |
f9a61eb4 | 180 | */ |
7a2508e1 JK |
181 | struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache, |
182 | u32 key) | |
f9a61eb4 JK |
183 | { |
184 | return __entry_find(cache, NULL, key); | |
185 | } | |
7a2508e1 | 186 | EXPORT_SYMBOL(mb_cache_entry_find_first); |
f9a61eb4 JK |
187 | |
188 | /* | |
b649668c | 189 | * mb_cache_entry_find_next - find next reusable entry with the same key |
f9a61eb4 JK |
190 | * @cache: cache where we should search |
191 | * @entry: entry to start search from | |
192 | * | |
b649668c EB |
193 | * Finds next reusable entry in the hash chain which has the same key as @entry. |
194 | * If @entry is unhashed (which can happen when deletion of entry races with the | |
195 | * search), finds the first reusable entry in the hash chain. The function drops | |
196 | * reference to @entry and returns with a reference to the found entry. | |
f9a61eb4 | 197 | */ |
7a2508e1 JK |
198 | struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache, |
199 | struct mb_cache_entry *entry) | |
f9a61eb4 JK |
200 | { |
201 | return __entry_find(cache, entry, entry->e_key); | |
202 | } | |
7a2508e1 | 203 | EXPORT_SYMBOL(mb_cache_entry_find_next); |
f9a61eb4 | 204 | |
6048c64b | 205 | /* |
c07dfcb4 | 206 | * mb_cache_entry_get - get a cache entry by value (and key) |
6048c64b | 207 | * @cache - cache we work with |
c07dfcb4 TE |
208 | * @key - key |
209 | * @value - value | |
6048c64b AG |
210 | */ |
211 | struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key, | |
c07dfcb4 | 212 | u64 value) |
6048c64b AG |
213 | { |
214 | struct hlist_bl_node *node; | |
215 | struct hlist_bl_head *head; | |
216 | struct mb_cache_entry *entry; | |
217 | ||
218 | head = mb_cache_entry_head(cache, key); | |
219 | hlist_bl_lock(head); | |
220 | hlist_bl_for_each_entry(entry, node, head, e_hash_list) { | |
c07dfcb4 | 221 | if (entry->e_key == key && entry->e_value == value) { |
6048c64b AG |
222 | atomic_inc(&entry->e_refcnt); |
223 | goto out; | |
224 | } | |
225 | } | |
226 | entry = NULL; | |
227 | out: | |
228 | hlist_bl_unlock(head); | |
229 | return entry; | |
230 | } | |
231 | EXPORT_SYMBOL(mb_cache_entry_get); | |
232 | ||
3dc96bba JK |
233 | /* mb_cache_entry_delete_or_get - remove a cache entry if it has no users |
234 | * @cache - cache we work with | |
235 | * @key - key | |
236 | * @value - value | |
237 | * | |
238 | * Remove entry from cache @cache with key @key and value @value. The removal | |
239 | * happens only if the entry is unused. The function returns NULL in case the | |
240 | * entry was successfully removed or there's no entry in cache. Otherwise the | |
241 | * function grabs reference of the entry that we failed to delete because it | |
242 | * still has users and return it. | |
243 | */ | |
244 | struct mb_cache_entry *mb_cache_entry_delete_or_get(struct mb_cache *cache, | |
245 | u32 key, u64 value) | |
246 | { | |
247 | struct hlist_bl_node *node; | |
248 | struct hlist_bl_head *head; | |
249 | struct mb_cache_entry *entry; | |
250 | ||
251 | head = mb_cache_entry_head(cache, key); | |
252 | hlist_bl_lock(head); | |
253 | hlist_bl_for_each_entry(entry, node, head, e_hash_list) { | |
254 | if (entry->e_key == key && entry->e_value == value) { | |
255 | if (atomic_read(&entry->e_refcnt) > 2) { | |
256 | atomic_inc(&entry->e_refcnt); | |
257 | hlist_bl_unlock(head); | |
258 | return entry; | |
259 | } | |
260 | /* We keep hash list reference to keep entry alive */ | |
261 | hlist_bl_del_init(&entry->e_hash_list); | |
262 | hlist_bl_unlock(head); | |
263 | spin_lock(&cache->c_list_lock); | |
264 | if (!list_empty(&entry->e_list)) { | |
265 | list_del_init(&entry->e_list); | |
266 | if (!WARN_ONCE(cache->c_entry_count == 0, | |
267 | "mbcache: attempt to decrement c_entry_count past zero")) | |
268 | cache->c_entry_count--; | |
269 | atomic_dec(&entry->e_refcnt); | |
270 | } | |
271 | spin_unlock(&cache->c_list_lock); | |
272 | mb_cache_entry_put(cache, entry); | |
273 | return NULL; | |
274 | } | |
275 | } | |
276 | hlist_bl_unlock(head); | |
277 | ||
278 | return NULL; | |
279 | } | |
280 | EXPORT_SYMBOL(mb_cache_entry_delete_or_get); | |
281 | ||
7a2508e1 | 282 | /* mb_cache_entry_touch - cache entry got used |
f9a61eb4 JK |
283 | * @cache - cache the entry belongs to |
284 | * @entry - entry that got used | |
285 | * | |
f0c8b462 | 286 | * Marks entry as used to give hit higher chances of surviving in cache. |
f9a61eb4 | 287 | */ |
7a2508e1 JK |
288 | void mb_cache_entry_touch(struct mb_cache *cache, |
289 | struct mb_cache_entry *entry) | |
f9a61eb4 | 290 | { |
dc8d5e56 | 291 | entry->e_referenced = 1; |
f9a61eb4 | 292 | } |
7a2508e1 | 293 | EXPORT_SYMBOL(mb_cache_entry_touch); |
f9a61eb4 | 294 | |
7a2508e1 JK |
295 | static unsigned long mb_cache_count(struct shrinker *shrink, |
296 | struct shrink_control *sc) | |
f9a61eb4 | 297 | { |
7a2508e1 JK |
298 | struct mb_cache *cache = container_of(shrink, struct mb_cache, |
299 | c_shrink); | |
f9a61eb4 JK |
300 | |
301 | return cache->c_entry_count; | |
302 | } | |
303 | ||
304 | /* Shrink number of entries in cache */ | |
7a2508e1 | 305 | static unsigned long mb_cache_shrink(struct mb_cache *cache, |
132d4e2d | 306 | unsigned long nr_to_scan) |
f9a61eb4 | 307 | { |
7a2508e1 | 308 | struct mb_cache_entry *entry; |
f9a61eb4 | 309 | struct hlist_bl_head *head; |
132d4e2d | 310 | unsigned long shrunk = 0; |
f9a61eb4 | 311 | |
f0c8b462 JK |
312 | spin_lock(&cache->c_list_lock); |
313 | while (nr_to_scan-- && !list_empty(&cache->c_list)) { | |
314 | entry = list_first_entry(&cache->c_list, | |
7a2508e1 | 315 | struct mb_cache_entry, e_list); |
58318914 | 316 | if (entry->e_referenced || atomic_read(&entry->e_refcnt) > 2) { |
dc8d5e56 | 317 | entry->e_referenced = 0; |
918b7306 | 318 | list_move_tail(&entry->e_list, &cache->c_list); |
f0c8b462 JK |
319 | continue; |
320 | } | |
321 | list_del_init(&entry->e_list); | |
f9a61eb4 JK |
322 | cache->c_entry_count--; |
323 | /* | |
324 | * We keep LRU list reference so that entry doesn't go away | |
325 | * from under us. | |
326 | */ | |
f0c8b462 | 327 | spin_unlock(&cache->c_list_lock); |
dc8d5e56 | 328 | head = mb_cache_entry_head(cache, entry->e_key); |
f9a61eb4 | 329 | hlist_bl_lock(head); |
58318914 JK |
330 | /* Now a reliable check if the entry didn't get used... */ |
331 | if (atomic_read(&entry->e_refcnt) > 2) { | |
332 | hlist_bl_unlock(head); | |
333 | spin_lock(&cache->c_list_lock); | |
334 | list_add_tail(&entry->e_list, &cache->c_list); | |
335 | cache->c_entry_count++; | |
336 | continue; | |
337 | } | |
f9a61eb4 JK |
338 | if (!hlist_bl_unhashed(&entry->e_hash_list)) { |
339 | hlist_bl_del_init(&entry->e_hash_list); | |
340 | atomic_dec(&entry->e_refcnt); | |
341 | } | |
342 | hlist_bl_unlock(head); | |
7a2508e1 | 343 | if (mb_cache_entry_put(cache, entry)) |
f9a61eb4 JK |
344 | shrunk++; |
345 | cond_resched(); | |
f0c8b462 | 346 | spin_lock(&cache->c_list_lock); |
f9a61eb4 | 347 | } |
f0c8b462 | 348 | spin_unlock(&cache->c_list_lock); |
f9a61eb4 JK |
349 | |
350 | return shrunk; | |
351 | } | |
352 | ||
7a2508e1 JK |
353 | static unsigned long mb_cache_scan(struct shrinker *shrink, |
354 | struct shrink_control *sc) | |
c2f3140f | 355 | { |
7a2508e1 | 356 | struct mb_cache *cache = container_of(shrink, struct mb_cache, |
c2f3140f | 357 | c_shrink); |
132d4e2d | 358 | return mb_cache_shrink(cache, sc->nr_to_scan); |
c2f3140f JK |
359 | } |
360 | ||
361 | /* We shrink 1/X of the cache when we have too many entries in it */ | |
362 | #define SHRINK_DIVISOR 16 | |
363 | ||
7a2508e1 | 364 | static void mb_cache_shrink_worker(struct work_struct *work) |
c2f3140f | 365 | { |
7a2508e1 JK |
366 | struct mb_cache *cache = container_of(work, struct mb_cache, |
367 | c_shrink_work); | |
368 | mb_cache_shrink(cache, cache->c_max_entries / SHRINK_DIVISOR); | |
c2f3140f JK |
369 | } |
370 | ||
f9a61eb4 | 371 | /* |
7a2508e1 | 372 | * mb_cache_create - create cache |
f9a61eb4 JK |
373 | * @bucket_bits: log2 of the hash table size |
374 | * | |
375 | * Create cache for keys with 2^bucket_bits hash entries. | |
376 | */ | |
7a2508e1 | 377 | struct mb_cache *mb_cache_create(int bucket_bits) |
f9a61eb4 | 378 | { |
7a2508e1 | 379 | struct mb_cache *cache; |
132d4e2d EB |
380 | unsigned long bucket_count = 1UL << bucket_bits; |
381 | unsigned long i; | |
f9a61eb4 | 382 | |
7a2508e1 | 383 | cache = kzalloc(sizeof(struct mb_cache), GFP_KERNEL); |
f9a61eb4 JK |
384 | if (!cache) |
385 | goto err_out; | |
386 | cache->c_bucket_bits = bucket_bits; | |
c2f3140f | 387 | cache->c_max_entries = bucket_count << 4; |
f0c8b462 JK |
388 | INIT_LIST_HEAD(&cache->c_list); |
389 | spin_lock_init(&cache->c_list_lock); | |
6da2ec56 KC |
390 | cache->c_hash = kmalloc_array(bucket_count, |
391 | sizeof(struct hlist_bl_head), | |
392 | GFP_KERNEL); | |
f9a61eb4 JK |
393 | if (!cache->c_hash) { |
394 | kfree(cache); | |
395 | goto err_out; | |
396 | } | |
397 | for (i = 0; i < bucket_count; i++) | |
398 | INIT_HLIST_BL_HEAD(&cache->c_hash[i]); | |
399 | ||
7a2508e1 JK |
400 | cache->c_shrink.count_objects = mb_cache_count; |
401 | cache->c_shrink.scan_objects = mb_cache_scan; | |
f9a61eb4 | 402 | cache->c_shrink.seeks = DEFAULT_SEEKS; |
8913f343 CY |
403 | if (register_shrinker(&cache->c_shrink)) { |
404 | kfree(cache->c_hash); | |
405 | kfree(cache); | |
406 | goto err_out; | |
407 | } | |
f9a61eb4 | 408 | |
7a2508e1 | 409 | INIT_WORK(&cache->c_shrink_work, mb_cache_shrink_worker); |
c2f3140f | 410 | |
f9a61eb4 JK |
411 | return cache; |
412 | ||
413 | err_out: | |
f9a61eb4 JK |
414 | return NULL; |
415 | } | |
7a2508e1 | 416 | EXPORT_SYMBOL(mb_cache_create); |
f9a61eb4 JK |
417 | |
418 | /* | |
7a2508e1 | 419 | * mb_cache_destroy - destroy cache |
f9a61eb4 JK |
420 | * @cache: the cache to destroy |
421 | * | |
422 | * Free all entries in cache and cache itself. Caller must make sure nobody | |
423 | * (except shrinker) can reach @cache when calling this. | |
424 | */ | |
7a2508e1 | 425 | void mb_cache_destroy(struct mb_cache *cache) |
f9a61eb4 | 426 | { |
7a2508e1 | 427 | struct mb_cache_entry *entry, *next; |
f9a61eb4 JK |
428 | |
429 | unregister_shrinker(&cache->c_shrink); | |
430 | ||
431 | /* | |
432 | * We don't bother with any locking. Cache must not be used at this | |
433 | * point. | |
434 | */ | |
f0c8b462 | 435 | list_for_each_entry_safe(entry, next, &cache->c_list, e_list) { |
f9a61eb4 JK |
436 | if (!hlist_bl_unhashed(&entry->e_hash_list)) { |
437 | hlist_bl_del_init(&entry->e_hash_list); | |
438 | atomic_dec(&entry->e_refcnt); | |
439 | } else | |
440 | WARN_ON(1); | |
f0c8b462 | 441 | list_del(&entry->e_list); |
f9a61eb4 | 442 | WARN_ON(atomic_read(&entry->e_refcnt) != 1); |
7a2508e1 | 443 | mb_cache_entry_put(cache, entry); |
f9a61eb4 JK |
444 | } |
445 | kfree(cache->c_hash); | |
446 | kfree(cache); | |
f9a61eb4 | 447 | } |
7a2508e1 | 448 | EXPORT_SYMBOL(mb_cache_destroy); |
f9a61eb4 | 449 | |
7a2508e1 | 450 | static int __init mbcache_init(void) |
f9a61eb4 | 451 | { |
7a2508e1 JK |
452 | mb_entry_cache = kmem_cache_create("mbcache", |
453 | sizeof(struct mb_cache_entry), 0, | |
f9a61eb4 | 454 | SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL); |
21d0f4fa EB |
455 | if (!mb_entry_cache) |
456 | return -ENOMEM; | |
f9a61eb4 JK |
457 | return 0; |
458 | } | |
459 | ||
7a2508e1 | 460 | static void __exit mbcache_exit(void) |
f9a61eb4 | 461 | { |
7a2508e1 | 462 | kmem_cache_destroy(mb_entry_cache); |
f9a61eb4 JK |
463 | } |
464 | ||
7a2508e1 JK |
465 | module_init(mbcache_init) |
466 | module_exit(mbcache_exit) | |
f9a61eb4 JK |
467 | |
468 | MODULE_AUTHOR("Jan Kara <jack@suse.cz>"); | |
469 | MODULE_DESCRIPTION("Meta block cache (for extended attributes)"); | |
470 | MODULE_LICENSE("GPL"); |