Blame view
fs/mbcache.c
12 KB
f9a61eb4e mbcache2: reimple... |
1 2 3 4 5 6 |
#include <linux/spinlock.h> #include <linux/slab.h> #include <linux/list.h> #include <linux/list_bl.h> #include <linux/module.h> #include <linux/sched.h> |
c2f3140fe mbcache2: limit c... |
7 |
#include <linux/workqueue.h> |
7a2508e1b mbcache2: rename ... |
8 |
#include <linux/mbcache.h> |
f9a61eb4e mbcache2: reimple... |
9 10 11 12 |
/* * Mbcache is a simple key-value store. Keys need not be unique, however * key-value pairs are expected to be unique (we use this fact in |
c07dfcb45 mbcache: make mbc... |
13 |
* mb_cache_entry_delete()). |
f9a61eb4e mbcache2: reimple... |
14 15 |
* * Ext2 and ext4 use this cache for deduplication of extended attribute blocks. |
dec214d00 ext4: xattr inode... |
16 17 18 19 20 |
* Ext4 also uses it for deduplication of xattr values stored in inodes. * They use hash of data as a key and provide a value that may represent a * block or inode number. That's why keys need not be unique (hash of different * data may be the same). However user provided value always uniquely * identifies a cache entry. |
f9a61eb4e mbcache2: reimple... |
21 22 23 24 25 |
* * We provide functions for creation and removal of entries, search by key, * and a special "delete entry with given key-value pair" operation. Fixed * size hash table is used for fast key lookups. */ |
7a2508e1b mbcache2: rename ... |
26 |
struct mb_cache { |
f9a61eb4e mbcache2: reimple... |
27 28 29 30 |
/* Hash table of entries */ struct hlist_bl_head *c_hash; /* log2 of hash table size */ int c_bucket_bits; |
c2f3140fe mbcache2: limit c... |
31 |
/* Maximum entries in cache to avoid degrading hash too much */ |
132d4e2d5 mbcache: use cons... |
32 |
unsigned long c_max_entries; |
f0c8b4623 mbcache2: Use ref... |
33 34 35 |
/* Protects c_list, c_entry_count */ spinlock_t c_list_lock; struct list_head c_list; |
f9a61eb4e mbcache2: reimple... |
36 37 38 |
/* Number of entries in cache */ unsigned long c_entry_count; struct shrinker c_shrink; |
c2f3140fe mbcache2: limit c... |
39 40 |
/* Work for shrinking when the cache has too many entries */ struct work_struct c_shrink_work; |
f9a61eb4e mbcache2: reimple... |
41 |
}; |
7a2508e1b mbcache2: rename ... |
42 |
static struct kmem_cache *mb_entry_cache; |
f9a61eb4e mbcache2: reimple... |
43 |
|
7a2508e1b mbcache2: rename ... |
44 |
static unsigned long mb_cache_shrink(struct mb_cache *cache, |
132d4e2d5 mbcache: use cons... |
45 |
unsigned long nr_to_scan); |
c2f3140fe mbcache2: limit c... |
46 |
|
dc8d5e565 mbcache: get rid ... |
47 48 |
static inline struct hlist_bl_head *mb_cache_entry_head(struct mb_cache *cache, u32 key) |
f0c8b4623 mbcache2: Use ref... |
49 |
{ |
dc8d5e565 mbcache: get rid ... |
50 |
return &cache->c_hash[hash_32(key, cache->c_bucket_bits)]; |
f0c8b4623 mbcache2: Use ref... |
51 |
} |
c2f3140fe mbcache2: limit c... |
52 53 54 55 56 |
/* * Number of entries to reclaim synchronously when there are too many entries * in cache */ #define SYNC_SHRINK_BATCH 64 |
f9a61eb4e mbcache2: reimple... |
57 |
/* |
7a2508e1b mbcache2: rename ... |
58 |
* mb_cache_entry_create - create entry in cache |
f9a61eb4e mbcache2: reimple... |
59 60 61 |
* @cache - cache where the entry should be created * @mask - gfp mask with which the entry should be allocated * @key - key of the entry |
c07dfcb45 mbcache: make mbc... |
62 63 |
* @value - value of the entry * @reusable - is the entry reusable by others? |
f9a61eb4e mbcache2: reimple... |
64 |
* |
c07dfcb45 mbcache: make mbc... |
65 66 67 |
* Creates entry in @cache with key @key and value @value. The function returns * -EBUSY if entry with the same key and value already exists in cache. * Otherwise 0 is returned. |
f9a61eb4e mbcache2: reimple... |
68 |
*/ |
7a2508e1b mbcache2: rename ... |
69 |
int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key, |
c07dfcb45 mbcache: make mbc... |
70 |
u64 value, bool reusable) |
f9a61eb4e mbcache2: reimple... |
71 |
{ |
7a2508e1b mbcache2: rename ... |
72 |
struct mb_cache_entry *entry, *dup; |
f9a61eb4e mbcache2: reimple... |
73 74 |
struct hlist_bl_node *dup_node; struct hlist_bl_head *head; |
c2f3140fe mbcache2: limit c... |
75 76 77 78 79 |
/* Schedule background reclaim if there are too many entries */ if (cache->c_entry_count >= cache->c_max_entries) schedule_work(&cache->c_shrink_work); /* Do some sync reclaim if background reclaim cannot keep up */ if (cache->c_entry_count >= 2*cache->c_max_entries) |
7a2508e1b mbcache2: rename ... |
80 |
mb_cache_shrink(cache, SYNC_SHRINK_BATCH); |
c2f3140fe mbcache2: limit c... |
81 |
|
7a2508e1b mbcache2: rename ... |
82 |
entry = kmem_cache_alloc(mb_entry_cache, mask); |
f9a61eb4e mbcache2: reimple... |
83 84 |
if (!entry) return -ENOMEM; |
f0c8b4623 mbcache2: Use ref... |
85 |
INIT_LIST_HEAD(&entry->e_list); |
f9a61eb4e mbcache2: reimple... |
86 87 88 |
/* One ref for hash, one ref returned */ atomic_set(&entry->e_refcnt, 1); entry->e_key = key; |
c07dfcb45 mbcache: make mbc... |
89 |
entry->e_value = value; |
6048c64b2 mbcache: add reus... |
90 |
entry->e_reusable = reusable; |
3876bbe27 mbcache: initiali... |
91 |
entry->e_referenced = 0; |
dc8d5e565 mbcache: get rid ... |
92 |
head = mb_cache_entry_head(cache, key); |
f9a61eb4e mbcache2: reimple... |
93 94 |
hlist_bl_lock(head); hlist_bl_for_each_entry(dup, dup_node, head, e_hash_list) { |
c07dfcb45 mbcache: make mbc... |
95 |
if (dup->e_key == key && dup->e_value == value) { |
f9a61eb4e mbcache2: reimple... |
96 |
hlist_bl_unlock(head); |
7a2508e1b mbcache2: rename ... |
97 |
kmem_cache_free(mb_entry_cache, entry); |
f9a61eb4e mbcache2: reimple... |
98 99 100 101 102 |
return -EBUSY; } } hlist_bl_add_head(&entry->e_hash_list, head); hlist_bl_unlock(head); |
f0c8b4623 mbcache2: Use ref... |
103 104 |
spin_lock(&cache->c_list_lock); list_add_tail(&entry->e_list, &cache->c_list); |
f9a61eb4e mbcache2: reimple... |
105 106 107 |
/* Grab ref for LRU list */ atomic_inc(&entry->e_refcnt); cache->c_entry_count++; |
f0c8b4623 mbcache2: Use ref... |
108 |
spin_unlock(&cache->c_list_lock); |
f9a61eb4e mbcache2: reimple... |
109 110 111 |
return 0; } |
7a2508e1b mbcache2: rename ... |
112 |
EXPORT_SYMBOL(mb_cache_entry_create); |
f9a61eb4e mbcache2: reimple... |
113 |
|
7a2508e1b mbcache2: rename ... |
114 |
void __mb_cache_entry_free(struct mb_cache_entry *entry) |
f9a61eb4e mbcache2: reimple... |
115 |
{ |
7a2508e1b mbcache2: rename ... |
116 |
kmem_cache_free(mb_entry_cache, entry); |
f9a61eb4e mbcache2: reimple... |
117 |
} |
7a2508e1b mbcache2: rename ... |
118 |
EXPORT_SYMBOL(__mb_cache_entry_free); |
f9a61eb4e mbcache2: reimple... |
119 |
|
7a2508e1b mbcache2: rename ... |
120 121 122 |
static struct mb_cache_entry *__entry_find(struct mb_cache *cache, struct mb_cache_entry *entry, u32 key) |
f9a61eb4e mbcache2: reimple... |
123 |
{ |
7a2508e1b mbcache2: rename ... |
124 |
struct mb_cache_entry *old_entry = entry; |
f9a61eb4e mbcache2: reimple... |
125 126 |
struct hlist_bl_node *node; struct hlist_bl_head *head; |
dc8d5e565 mbcache: get rid ... |
127 |
head = mb_cache_entry_head(cache, key); |
f9a61eb4e mbcache2: reimple... |
128 129 130 131 132 133 |
hlist_bl_lock(head); if (entry && !hlist_bl_unhashed(&entry->e_hash_list)) node = entry->e_hash_list.next; else node = hlist_bl_first(head); while (node) { |
7a2508e1b mbcache2: rename ... |
134 |
entry = hlist_bl_entry(node, struct mb_cache_entry, |
f9a61eb4e mbcache2: reimple... |
135 |
e_hash_list); |
6048c64b2 mbcache: add reus... |
136 |
if (entry->e_key == key && entry->e_reusable) { |
f9a61eb4e mbcache2: reimple... |
137 138 139 140 141 142 143 144 145 |
atomic_inc(&entry->e_refcnt); goto out; } node = node->next; } entry = NULL; out: hlist_bl_unlock(head); if (old_entry) |
7a2508e1b mbcache2: rename ... |
146 |
mb_cache_entry_put(cache, old_entry); |
f9a61eb4e mbcache2: reimple... |
147 148 149 150 151 |
return entry; } /* |
b649668c0 mbcache: document... |
152 |
* mb_cache_entry_find_first - find the first reusable entry with the given key |
f9a61eb4e mbcache2: reimple... |
153 154 155 |
* @cache: cache where we should search * @key: key to look for * |
b649668c0 mbcache: document... |
156 157 |
* Search in @cache for a reusable entry with key @key. Grabs reference to the * first reusable entry found and returns the entry. |
f9a61eb4e mbcache2: reimple... |
158 |
*/ |
7a2508e1b mbcache2: rename ... |
159 160 |
struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache, u32 key) |
f9a61eb4e mbcache2: reimple... |
161 162 163 |
{ return __entry_find(cache, NULL, key); } |
7a2508e1b mbcache2: rename ... |
164 |
EXPORT_SYMBOL(mb_cache_entry_find_first); |
f9a61eb4e mbcache2: reimple... |
165 166 |
/* |
b649668c0 mbcache: document... |
167 |
* mb_cache_entry_find_next - find next reusable entry with the same key |
f9a61eb4e mbcache2: reimple... |
168 169 170 |
* @cache: cache where we should search * @entry: entry to start search from * |
b649668c0 mbcache: document... |
171 172 173 174 |
* Finds next reusable entry in the hash chain which has the same key as @entry. * If @entry is unhashed (which can happen when deletion of entry races with the * search), finds the first reusable entry in the hash chain. The function drops * reference to @entry and returns with a reference to the found entry. |
f9a61eb4e mbcache2: reimple... |
175 |
*/ |
7a2508e1b mbcache2: rename ... |
176 177 |
struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache, struct mb_cache_entry *entry) |
f9a61eb4e mbcache2: reimple... |
178 179 180 |
{ return __entry_find(cache, entry, entry->e_key); } |
7a2508e1b mbcache2: rename ... |
181 |
EXPORT_SYMBOL(mb_cache_entry_find_next); |
f9a61eb4e mbcache2: reimple... |
182 |
|
6048c64b2 mbcache: add reus... |
183 |
/* |
c07dfcb45 mbcache: make mbc... |
184 |
* mb_cache_entry_get - get a cache entry by value (and key) |
6048c64b2 mbcache: add reus... |
185 |
* @cache - cache we work with |
c07dfcb45 mbcache: make mbc... |
186 187 |
* @key - key * @value - value |
6048c64b2 mbcache: add reus... |
188 189 |
*/ struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key, |
c07dfcb45 mbcache: make mbc... |
190 |
u64 value) |
6048c64b2 mbcache: add reus... |
191 192 193 194 195 196 197 198 |
{ struct hlist_bl_node *node; struct hlist_bl_head *head; struct mb_cache_entry *entry; head = mb_cache_entry_head(cache, key); hlist_bl_lock(head); hlist_bl_for_each_entry(entry, node, head, e_hash_list) { |
c07dfcb45 mbcache: make mbc... |
199 |
if (entry->e_key == key && entry->e_value == value) { |
6048c64b2 mbcache: add reus... |
200 201 202 203 204 205 206 207 208 209 |
atomic_inc(&entry->e_refcnt); goto out; } } entry = NULL; out: hlist_bl_unlock(head); return entry; } EXPORT_SYMBOL(mb_cache_entry_get); |
c07dfcb45 mbcache: make mbc... |
210 |
/* mb_cache_entry_delete - remove a cache entry |
f9a61eb4e mbcache2: reimple... |
211 |
* @cache - cache we work with |
c07dfcb45 mbcache: make mbc... |
212 213 |
* @key - key * @value - value |
f9a61eb4e mbcache2: reimple... |
214 |
* |
c07dfcb45 mbcache: make mbc... |
215 |
* Remove entry from cache @cache with key @key and value @value. |
f9a61eb4e mbcache2: reimple... |
216 |
*/ |
c07dfcb45 mbcache: make mbc... |
217 |
void mb_cache_entry_delete(struct mb_cache *cache, u32 key, u64 value) |
f9a61eb4e mbcache2: reimple... |
218 219 220 |
{ struct hlist_bl_node *node; struct hlist_bl_head *head; |
7a2508e1b mbcache2: rename ... |
221 |
struct mb_cache_entry *entry; |
f9a61eb4e mbcache2: reimple... |
222 |
|
dc8d5e565 mbcache: get rid ... |
223 |
head = mb_cache_entry_head(cache, key); |
f9a61eb4e mbcache2: reimple... |
224 225 |
hlist_bl_lock(head); hlist_bl_for_each_entry(entry, node, head, e_hash_list) { |
c07dfcb45 mbcache: make mbc... |
226 |
if (entry->e_key == key && entry->e_value == value) { |
f9a61eb4e mbcache2: reimple... |
227 228 229 |
/* We keep hash list reference to keep entry alive */ hlist_bl_del_init(&entry->e_hash_list); hlist_bl_unlock(head); |
f0c8b4623 mbcache2: Use ref... |
230 231 232 |
spin_lock(&cache->c_list_lock); if (!list_empty(&entry->e_list)) { list_del_init(&entry->e_list); |
9ee93ba3c mbcache: make sur... |
233 234 235 |
if (!WARN_ONCE(cache->c_entry_count == 0, "mbcache: attempt to decrement c_entry_count past zero")) cache->c_entry_count--; |
f9a61eb4e mbcache2: reimple... |
236 237 |
atomic_dec(&entry->e_refcnt); } |
f0c8b4623 mbcache2: Use ref... |
238 |
spin_unlock(&cache->c_list_lock); |
7a2508e1b mbcache2: rename ... |
239 |
mb_cache_entry_put(cache, entry); |
f9a61eb4e mbcache2: reimple... |
240 241 242 243 244 |
return; } } hlist_bl_unlock(head); } |
c07dfcb45 mbcache: make mbc... |
245 |
EXPORT_SYMBOL(mb_cache_entry_delete); |
f9a61eb4e mbcache2: reimple... |
246 |
|
7a2508e1b mbcache2: rename ... |
247 |
/* mb_cache_entry_touch - cache entry got used |
f9a61eb4e mbcache2: reimple... |
248 249 250 |
* @cache - cache the entry belongs to * @entry - entry that got used * |
f0c8b4623 mbcache2: Use ref... |
251 |
* Marks entry as used to give hit higher chances of surviving in cache. |
f9a61eb4e mbcache2: reimple... |
252 |
*/ |
7a2508e1b mbcache2: rename ... |
253 254 |
void mb_cache_entry_touch(struct mb_cache *cache, struct mb_cache_entry *entry) |
f9a61eb4e mbcache2: reimple... |
255 |
{ |
dc8d5e565 mbcache: get rid ... |
256 |
entry->e_referenced = 1; |
f9a61eb4e mbcache2: reimple... |
257 |
} |
7a2508e1b mbcache2: rename ... |
258 |
EXPORT_SYMBOL(mb_cache_entry_touch); |
f9a61eb4e mbcache2: reimple... |
259 |
|
7a2508e1b mbcache2: rename ... |
260 261 |
static unsigned long mb_cache_count(struct shrinker *shrink, struct shrink_control *sc) |
f9a61eb4e mbcache2: reimple... |
262 |
{ |
7a2508e1b mbcache2: rename ... |
263 264 |
struct mb_cache *cache = container_of(shrink, struct mb_cache, c_shrink); |
f9a61eb4e mbcache2: reimple... |
265 266 267 268 269 |
return cache->c_entry_count; } /* Shrink number of entries in cache */ |
7a2508e1b mbcache2: rename ... |
270 |
static unsigned long mb_cache_shrink(struct mb_cache *cache, |
132d4e2d5 mbcache: use cons... |
271 |
unsigned long nr_to_scan) |
f9a61eb4e mbcache2: reimple... |
272 |
{ |
7a2508e1b mbcache2: rename ... |
273 |
struct mb_cache_entry *entry; |
f9a61eb4e mbcache2: reimple... |
274 |
struct hlist_bl_head *head; |
132d4e2d5 mbcache: use cons... |
275 |
unsigned long shrunk = 0; |
f9a61eb4e mbcache2: reimple... |
276 |
|
f0c8b4623 mbcache2: Use ref... |
277 278 279 |
spin_lock(&cache->c_list_lock); while (nr_to_scan-- && !list_empty(&cache->c_list)) { entry = list_first_entry(&cache->c_list, |
7a2508e1b mbcache2: rename ... |
280 |
struct mb_cache_entry, e_list); |
dc8d5e565 mbcache: get rid ... |
281 282 |
if (entry->e_referenced) { entry->e_referenced = 0; |
918b7306e mbcache: correctl... |
283 |
list_move_tail(&entry->e_list, &cache->c_list); |
f0c8b4623 mbcache2: Use ref... |
284 285 286 |
continue; } list_del_init(&entry->e_list); |
f9a61eb4e mbcache2: reimple... |
287 288 289 290 291 |
cache->c_entry_count--; /* * We keep LRU list reference so that entry doesn't go away * from under us. */ |
f0c8b4623 mbcache2: Use ref... |
292 |
spin_unlock(&cache->c_list_lock); |
dc8d5e565 mbcache: get rid ... |
293 |
head = mb_cache_entry_head(cache, entry->e_key); |
f9a61eb4e mbcache2: reimple... |
294 295 296 297 298 299 |
hlist_bl_lock(head); if (!hlist_bl_unhashed(&entry->e_hash_list)) { hlist_bl_del_init(&entry->e_hash_list); atomic_dec(&entry->e_refcnt); } hlist_bl_unlock(head); |
7a2508e1b mbcache2: rename ... |
300 |
if (mb_cache_entry_put(cache, entry)) |
f9a61eb4e mbcache2: reimple... |
301 302 |
shrunk++; cond_resched(); |
f0c8b4623 mbcache2: Use ref... |
303 |
spin_lock(&cache->c_list_lock); |
f9a61eb4e mbcache2: reimple... |
304 |
} |
f0c8b4623 mbcache2: Use ref... |
305 |
spin_unlock(&cache->c_list_lock); |
f9a61eb4e mbcache2: reimple... |
306 307 308 |
return shrunk; } |
7a2508e1b mbcache2: rename ... |
309 310 |
static unsigned long mb_cache_scan(struct shrinker *shrink, struct shrink_control *sc) |
c2f3140fe mbcache2: limit c... |
311 |
{ |
7a2508e1b mbcache2: rename ... |
312 |
struct mb_cache *cache = container_of(shrink, struct mb_cache, |
c2f3140fe mbcache2: limit c... |
313 |
c_shrink); |
132d4e2d5 mbcache: use cons... |
314 |
return mb_cache_shrink(cache, sc->nr_to_scan); |
c2f3140fe mbcache2: limit c... |
315 316 317 318 |
} /* We shrink 1/X of the cache when we have too many entries in it */ #define SHRINK_DIVISOR 16 |
7a2508e1b mbcache2: rename ... |
319 |
static void mb_cache_shrink_worker(struct work_struct *work) |
c2f3140fe mbcache2: limit c... |
320 |
{ |
7a2508e1b mbcache2: rename ... |
321 322 323 |
struct mb_cache *cache = container_of(work, struct mb_cache, c_shrink_work); mb_cache_shrink(cache, cache->c_max_entries / SHRINK_DIVISOR); |
c2f3140fe mbcache2: limit c... |
324 |
} |
f9a61eb4e mbcache2: reimple... |
325 |
/* |
7a2508e1b mbcache2: rename ... |
326 |
* mb_cache_create - create cache |
f9a61eb4e mbcache2: reimple... |
327 328 329 330 |
* @bucket_bits: log2 of the hash table size * * Create cache for keys with 2^bucket_bits hash entries. */ |
7a2508e1b mbcache2: rename ... |
331 |
struct mb_cache *mb_cache_create(int bucket_bits) |
f9a61eb4e mbcache2: reimple... |
332 |
{ |
7a2508e1b mbcache2: rename ... |
333 |
struct mb_cache *cache; |
132d4e2d5 mbcache: use cons... |
334 335 |
unsigned long bucket_count = 1UL << bucket_bits; unsigned long i; |
f9a61eb4e mbcache2: reimple... |
336 |
|
7a2508e1b mbcache2: rename ... |
337 |
cache = kzalloc(sizeof(struct mb_cache), GFP_KERNEL); |
f9a61eb4e mbcache2: reimple... |
338 339 340 |
if (!cache) goto err_out; cache->c_bucket_bits = bucket_bits; |
c2f3140fe mbcache2: limit c... |
341 |
cache->c_max_entries = bucket_count << 4; |
f0c8b4623 mbcache2: Use ref... |
342 343 |
INIT_LIST_HEAD(&cache->c_list); spin_lock_init(&cache->c_list_lock); |
6da2ec560 treewide: kmalloc... |
344 345 346 |
cache->c_hash = kmalloc_array(bucket_count, sizeof(struct hlist_bl_head), GFP_KERNEL); |
f9a61eb4e mbcache2: reimple... |
347 348 349 350 351 352 |
if (!cache->c_hash) { kfree(cache); goto err_out; } for (i = 0; i < bucket_count; i++) INIT_HLIST_BL_HEAD(&cache->c_hash[i]); |
7a2508e1b mbcache2: rename ... |
353 354 |
cache->c_shrink.count_objects = mb_cache_count; cache->c_shrink.scan_objects = mb_cache_scan; |
f9a61eb4e mbcache2: reimple... |
355 |
cache->c_shrink.seeks = DEFAULT_SEEKS; |
8913f343c mbcache: fix to d... |
356 357 358 359 360 |
if (register_shrinker(&cache->c_shrink)) { kfree(cache->c_hash); kfree(cache); goto err_out; } |
f9a61eb4e mbcache2: reimple... |
361 |
|
7a2508e1b mbcache2: rename ... |
362 |
INIT_WORK(&cache->c_shrink_work, mb_cache_shrink_worker); |
c2f3140fe mbcache2: limit c... |
363 |
|
f9a61eb4e mbcache2: reimple... |
364 365 366 |
return cache; err_out: |
f9a61eb4e mbcache2: reimple... |
367 368 |
return NULL; } |
7a2508e1b mbcache2: rename ... |
369 |
EXPORT_SYMBOL(mb_cache_create); |
f9a61eb4e mbcache2: reimple... |
370 371 |
/* |
7a2508e1b mbcache2: rename ... |
372 |
* mb_cache_destroy - destroy cache |
f9a61eb4e mbcache2: reimple... |
373 374 375 376 377 |
* @cache: the cache to destroy * * Free all entries in cache and cache itself. Caller must make sure nobody * (except shrinker) can reach @cache when calling this. */ |
7a2508e1b mbcache2: rename ... |
378 |
void mb_cache_destroy(struct mb_cache *cache) |
f9a61eb4e mbcache2: reimple... |
379 |
{ |
7a2508e1b mbcache2: rename ... |
380 |
struct mb_cache_entry *entry, *next; |
f9a61eb4e mbcache2: reimple... |
381 382 383 384 385 386 387 |
unregister_shrinker(&cache->c_shrink); /* * We don't bother with any locking. Cache must not be used at this * point. */ |
f0c8b4623 mbcache2: Use ref... |
388 |
list_for_each_entry_safe(entry, next, &cache->c_list, e_list) { |
f9a61eb4e mbcache2: reimple... |
389 390 391 392 393 |
if (!hlist_bl_unhashed(&entry->e_hash_list)) { hlist_bl_del_init(&entry->e_hash_list); atomic_dec(&entry->e_refcnt); } else WARN_ON(1); |
f0c8b4623 mbcache2: Use ref... |
394 |
list_del(&entry->e_list); |
f9a61eb4e mbcache2: reimple... |
395 |
WARN_ON(atomic_read(&entry->e_refcnt) != 1); |
7a2508e1b mbcache2: rename ... |
396 |
mb_cache_entry_put(cache, entry); |
f9a61eb4e mbcache2: reimple... |
397 398 399 |
} kfree(cache->c_hash); kfree(cache); |
f9a61eb4e mbcache2: reimple... |
400 |
} |
7a2508e1b mbcache2: rename ... |
401 |
EXPORT_SYMBOL(mb_cache_destroy); |
f9a61eb4e mbcache2: reimple... |
402 |
|
7a2508e1b mbcache2: rename ... |
403 |
static int __init mbcache_init(void) |
f9a61eb4e mbcache2: reimple... |
404 |
{ |
7a2508e1b mbcache2: rename ... |
405 406 |
mb_entry_cache = kmem_cache_create("mbcache", sizeof(struct mb_cache_entry), 0, |
f9a61eb4e mbcache2: reimple... |
407 |
SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL); |
21d0f4fa8 mbcache: don't BU... |
408 409 |
if (!mb_entry_cache) return -ENOMEM; |
f9a61eb4e mbcache2: reimple... |
410 411 |
return 0; } |
7a2508e1b mbcache2: rename ... |
412 |
static void __exit mbcache_exit(void) |
f9a61eb4e mbcache2: reimple... |
413 |
{ |
7a2508e1b mbcache2: rename ... |
414 |
kmem_cache_destroy(mb_entry_cache); |
f9a61eb4e mbcache2: reimple... |
415 |
} |
7a2508e1b mbcache2: rename ... |
416 417 |
module_init(mbcache_init) module_exit(mbcache_exit) |
f9a61eb4e mbcache2: reimple... |
418 419 420 421 |
MODULE_AUTHOR("Jan Kara <jack@suse.cz>"); MODULE_DESCRIPTION("Meta block cache (for extended attributes)"); MODULE_LICENSE("GPL"); |