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Source at commit b386be689295730688885552666ea40b2e639b14 created 11 years 11 months ago. By Maarten ter Huurne, Revert "MIPS: JZ4740: reset: Initialize hibernate wakeup counters." | |
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1 | /* |
2 | * linux/fs/mbcache.c |
3 | * (C) 2001-2002 Andreas Gruenbacher, <a.gruenbacher@computer.org> |
4 | */ |
5 | |
6 | /* |
7 | * Filesystem Meta Information Block Cache (mbcache) |
8 | * |
9 | * The mbcache caches blocks of block devices that need to be located |
10 | * by their device/block number, as well as by other criteria (such |
11 | * as the block's contents). |
12 | * |
13 | * There can only be one cache entry in a cache per device and block number. |
14 | * Additional indexes need not be unique in this sense. The number of |
15 | * additional indexes (=other criteria) can be hardwired at compile time |
16 | * or specified at cache create time. |
17 | * |
18 | * Each cache entry is of fixed size. An entry may be `valid' or `invalid' |
19 | * in the cache. A valid entry is in the main hash tables of the cache, |
20 | * and may also be in the lru list. An invalid entry is not in any hashes |
21 | * or lists. |
22 | * |
23 | * A valid cache entry is only in the lru list if no handles refer to it. |
24 | * Invalid cache entries will be freed when the last handle to the cache |
25 | * entry is released. Entries that cannot be freed immediately are put |
26 | * back on the lru list. |
27 | */ |
28 | |
29 | #include <linux/kernel.h> |
30 | #include <linux/module.h> |
31 | |
32 | #include <linux/hash.h> |
33 | #include <linux/fs.h> |
34 | #include <linux/mm.h> |
35 | #include <linux/slab.h> |
36 | #include <linux/sched.h> |
37 | #include <linux/init.h> |
38 | #include <linux/mbcache.h> |
39 | |
40 | |
41 | #ifdef MB_CACHE_DEBUG |
42 | # define mb_debug(f...) do { \ |
43 | printk(KERN_DEBUG f); \ |
44 | printk("\n"); \ |
45 | } while (0) |
46 | #define mb_assert(c) do { if (!(c)) \ |
47 | printk(KERN_ERR "assertion " #c " failed\n"); \ |
48 | } while(0) |
49 | #else |
50 | # define mb_debug(f...) do { } while(0) |
51 | # define mb_assert(c) do { } while(0) |
52 | #endif |
53 | #define mb_error(f...) do { \ |
54 | printk(KERN_ERR f); \ |
55 | printk("\n"); \ |
56 | } while(0) |
57 | |
58 | #define MB_CACHE_WRITER ((unsigned short)~0U >> 1) |
59 | |
60 | static DECLARE_WAIT_QUEUE_HEAD(mb_cache_queue); |
61 | |
62 | MODULE_AUTHOR("Andreas Gruenbacher <a.gruenbacher@computer.org>"); |
63 | MODULE_DESCRIPTION("Meta block cache (for extended attributes)"); |
64 | MODULE_LICENSE("GPL"); |
65 | |
66 | EXPORT_SYMBOL(mb_cache_create); |
67 | EXPORT_SYMBOL(mb_cache_shrink); |
68 | EXPORT_SYMBOL(mb_cache_destroy); |
69 | EXPORT_SYMBOL(mb_cache_entry_alloc); |
70 | EXPORT_SYMBOL(mb_cache_entry_insert); |
71 | EXPORT_SYMBOL(mb_cache_entry_release); |
72 | EXPORT_SYMBOL(mb_cache_entry_free); |
73 | EXPORT_SYMBOL(mb_cache_entry_get); |
74 | #if !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0) |
75 | EXPORT_SYMBOL(mb_cache_entry_find_first); |
76 | EXPORT_SYMBOL(mb_cache_entry_find_next); |
77 | #endif |
78 | |
79 | /* |
80 | * Global data: list of all mbcache's, lru list, and a spinlock for |
81 | * accessing cache data structures on SMP machines. The lru list is |
82 | * global across all mbcaches. |
83 | */ |
84 | |
85 | static LIST_HEAD(mb_cache_list); |
86 | static LIST_HEAD(mb_cache_lru_list); |
87 | static DEFINE_SPINLOCK(mb_cache_spinlock); |
88 | |
89 | /* |
90 | * What the mbcache registers as to get shrunk dynamically. |
91 | */ |
92 | |
93 | static int mb_cache_shrink_fn(struct shrinker *shrink, |
94 | struct shrink_control *sc); |
95 | |
96 | static struct shrinker mb_cache_shrinker = { |
97 | .shrink = mb_cache_shrink_fn, |
98 | .seeks = DEFAULT_SEEKS, |
99 | }; |
100 | |
101 | static inline int |
102 | __mb_cache_entry_is_hashed(struct mb_cache_entry *ce) |
103 | { |
104 | return !list_empty(&ce->e_block_list); |
105 | } |
106 | |
107 | |
108 | static void |
109 | __mb_cache_entry_unhash(struct mb_cache_entry *ce) |
110 | { |
111 | if (__mb_cache_entry_is_hashed(ce)) { |
112 | list_del_init(&ce->e_block_list); |
113 | list_del(&ce->e_index.o_list); |
114 | } |
115 | } |
116 | |
117 | |
118 | static void |
119 | __mb_cache_entry_forget(struct mb_cache_entry *ce, gfp_t gfp_mask) |
120 | { |
121 | struct mb_cache *cache = ce->e_cache; |
122 | |
123 | mb_assert(!(ce->e_used || ce->e_queued)); |
124 | kmem_cache_free(cache->c_entry_cache, ce); |
125 | atomic_dec(&cache->c_entry_count); |
126 | } |
127 | |
128 | |
129 | static void |
130 | __mb_cache_entry_release_unlock(struct mb_cache_entry *ce) |
131 | __releases(mb_cache_spinlock) |
132 | { |
133 | /* Wake up all processes queuing for this cache entry. */ |
134 | if (ce->e_queued) |
135 | wake_up_all(&mb_cache_queue); |
136 | if (ce->e_used >= MB_CACHE_WRITER) |
137 | ce->e_used -= MB_CACHE_WRITER; |
138 | ce->e_used--; |
139 | if (!(ce->e_used || ce->e_queued)) { |
140 | if (!__mb_cache_entry_is_hashed(ce)) |
141 | goto forget; |
142 | mb_assert(list_empty(&ce->e_lru_list)); |
143 | list_add_tail(&ce->e_lru_list, &mb_cache_lru_list); |
144 | } |
145 | spin_unlock(&mb_cache_spinlock); |
146 | return; |
147 | forget: |
148 | spin_unlock(&mb_cache_spinlock); |
149 | __mb_cache_entry_forget(ce, GFP_KERNEL); |
150 | } |
151 | |
152 | |
153 | /* |
154 | * mb_cache_shrink_fn() memory pressure callback |
155 | * |
156 | * This function is called by the kernel memory management when memory |
157 | * gets low. |
158 | * |
159 | * @shrink: (ignored) |
160 | * @sc: shrink_control passed from reclaim |
161 | * |
162 | * Returns the number of objects which are present in the cache. |
163 | */ |
164 | static int |
165 | mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc) |
166 | { |
167 | LIST_HEAD(free_list); |
168 | struct mb_cache *cache; |
169 | struct mb_cache_entry *entry, *tmp; |
170 | int count = 0; |
171 | int nr_to_scan = sc->nr_to_scan; |
172 | gfp_t gfp_mask = sc->gfp_mask; |
173 | |
174 | mb_debug("trying to free %d entries", nr_to_scan); |
175 | spin_lock(&mb_cache_spinlock); |
176 | while (nr_to_scan-- && !list_empty(&mb_cache_lru_list)) { |
177 | struct mb_cache_entry *ce = |
178 | list_entry(mb_cache_lru_list.next, |
179 | struct mb_cache_entry, e_lru_list); |
180 | list_move_tail(&ce->e_lru_list, &free_list); |
181 | __mb_cache_entry_unhash(ce); |
182 | } |
183 | list_for_each_entry(cache, &mb_cache_list, c_cache_list) { |
184 | mb_debug("cache %s (%d)", cache->c_name, |
185 | atomic_read(&cache->c_entry_count)); |
186 | count += atomic_read(&cache->c_entry_count); |
187 | } |
188 | spin_unlock(&mb_cache_spinlock); |
189 | list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) { |
190 | __mb_cache_entry_forget(entry, gfp_mask); |
191 | } |
192 | return (count / 100) * sysctl_vfs_cache_pressure; |
193 | } |
194 | |
195 | |
196 | /* |
197 | * mb_cache_create() create a new cache |
198 | * |
199 | * All entries in one cache are equal size. Cache entries may be from |
200 | * multiple devices. If this is the first mbcache created, registers |
201 | * the cache with kernel memory management. Returns NULL if no more |
202 | * memory was available. |
203 | * |
204 | * @name: name of the cache (informal) |
205 | * @bucket_bits: log2(number of hash buckets) |
206 | */ |
207 | struct mb_cache * |
208 | mb_cache_create(const char *name, int bucket_bits) |
209 | { |
210 | int n, bucket_count = 1 << bucket_bits; |
211 | struct mb_cache *cache = NULL; |
212 | |
213 | cache = kmalloc(sizeof(struct mb_cache), GFP_KERNEL); |
214 | if (!cache) |
215 | return NULL; |
216 | cache->c_name = name; |
217 | atomic_set(&cache->c_entry_count, 0); |
218 | cache->c_bucket_bits = bucket_bits; |
219 | cache->c_block_hash = kmalloc(bucket_count * sizeof(struct list_head), |
220 | GFP_KERNEL); |
221 | if (!cache->c_block_hash) |
222 | goto fail; |
223 | for (n=0; n<bucket_count; n++) |
224 | INIT_LIST_HEAD(&cache->c_block_hash[n]); |
225 | cache->c_index_hash = kmalloc(bucket_count * sizeof(struct list_head), |
226 | GFP_KERNEL); |
227 | if (!cache->c_index_hash) |
228 | goto fail; |
229 | for (n=0; n<bucket_count; n++) |
230 | INIT_LIST_HEAD(&cache->c_index_hash[n]); |
231 | cache->c_entry_cache = kmem_cache_create(name, |
232 | sizeof(struct mb_cache_entry), 0, |
233 | SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL); |
234 | if (!cache->c_entry_cache) |
235 | goto fail2; |
236 | |
237 | /* |
238 | * Set an upper limit on the number of cache entries so that the hash |
239 | * chains won't grow too long. |
240 | */ |
241 | cache->c_max_entries = bucket_count << 4; |
242 | |
243 | spin_lock(&mb_cache_spinlock); |
244 | list_add(&cache->c_cache_list, &mb_cache_list); |
245 | spin_unlock(&mb_cache_spinlock); |
246 | return cache; |
247 | |
248 | fail2: |
249 | kfree(cache->c_index_hash); |
250 | |
251 | fail: |
252 | kfree(cache->c_block_hash); |
253 | kfree(cache); |
254 | return NULL; |
255 | } |
256 | |
257 | |
258 | /* |
259 | * mb_cache_shrink() |
260 | * |
261 | * Removes all cache entries of a device from the cache. All cache entries |
262 | * currently in use cannot be freed, and thus remain in the cache. All others |
263 | * are freed. |
264 | * |
265 | * @bdev: which device's cache entries to shrink |
266 | */ |
267 | void |
268 | mb_cache_shrink(struct block_device *bdev) |
269 | { |
270 | LIST_HEAD(free_list); |
271 | struct list_head *l, *ltmp; |
272 | |
273 | spin_lock(&mb_cache_spinlock); |
274 | list_for_each_safe(l, ltmp, &mb_cache_lru_list) { |
275 | struct mb_cache_entry *ce = |
276 | list_entry(l, struct mb_cache_entry, e_lru_list); |
277 | if (ce->e_bdev == bdev) { |
278 | list_move_tail(&ce->e_lru_list, &free_list); |
279 | __mb_cache_entry_unhash(ce); |
280 | } |
281 | } |
282 | spin_unlock(&mb_cache_spinlock); |
283 | list_for_each_safe(l, ltmp, &free_list) { |
284 | __mb_cache_entry_forget(list_entry(l, struct mb_cache_entry, |
285 | e_lru_list), GFP_KERNEL); |
286 | } |
287 | } |
288 | |
289 | |
290 | /* |
291 | * mb_cache_destroy() |
292 | * |
293 | * Shrinks the cache to its minimum possible size (hopefully 0 entries), |
294 | * and then destroys it. If this was the last mbcache, un-registers the |
295 | * mbcache from kernel memory management. |
296 | */ |
297 | void |
298 | mb_cache_destroy(struct mb_cache *cache) |
299 | { |
300 | LIST_HEAD(free_list); |
301 | struct list_head *l, *ltmp; |
302 | |
303 | spin_lock(&mb_cache_spinlock); |
304 | list_for_each_safe(l, ltmp, &mb_cache_lru_list) { |
305 | struct mb_cache_entry *ce = |
306 | list_entry(l, struct mb_cache_entry, e_lru_list); |
307 | if (ce->e_cache == cache) { |
308 | list_move_tail(&ce->e_lru_list, &free_list); |
309 | __mb_cache_entry_unhash(ce); |
310 | } |
311 | } |
312 | list_del(&cache->c_cache_list); |
313 | spin_unlock(&mb_cache_spinlock); |
314 | |
315 | list_for_each_safe(l, ltmp, &free_list) { |
316 | __mb_cache_entry_forget(list_entry(l, struct mb_cache_entry, |
317 | e_lru_list), GFP_KERNEL); |
318 | } |
319 | |
320 | if (atomic_read(&cache->c_entry_count) > 0) { |
321 | mb_error("cache %s: %d orphaned entries", |
322 | cache->c_name, |
323 | atomic_read(&cache->c_entry_count)); |
324 | } |
325 | |
326 | kmem_cache_destroy(cache->c_entry_cache); |
327 | |
328 | kfree(cache->c_index_hash); |
329 | kfree(cache->c_block_hash); |
330 | kfree(cache); |
331 | } |
332 | |
333 | /* |
334 | * mb_cache_entry_alloc() |
335 | * |
336 | * Allocates a new cache entry. The new entry will not be valid initially, |
337 | * and thus cannot be looked up yet. It should be filled with data, and |
338 | * then inserted into the cache using mb_cache_entry_insert(). Returns NULL |
339 | * if no more memory was available. |
340 | */ |
341 | struct mb_cache_entry * |
342 | mb_cache_entry_alloc(struct mb_cache *cache, gfp_t gfp_flags) |
343 | { |
344 | struct mb_cache_entry *ce = NULL; |
345 | |
346 | if (atomic_read(&cache->c_entry_count) >= cache->c_max_entries) { |
347 | spin_lock(&mb_cache_spinlock); |
348 | if (!list_empty(&mb_cache_lru_list)) { |
349 | ce = list_entry(mb_cache_lru_list.next, |
350 | struct mb_cache_entry, e_lru_list); |
351 | list_del_init(&ce->e_lru_list); |
352 | __mb_cache_entry_unhash(ce); |
353 | } |
354 | spin_unlock(&mb_cache_spinlock); |
355 | } |
356 | if (!ce) { |
357 | ce = kmem_cache_alloc(cache->c_entry_cache, gfp_flags); |
358 | if (!ce) |
359 | return NULL; |
360 | atomic_inc(&cache->c_entry_count); |
361 | INIT_LIST_HEAD(&ce->e_lru_list); |
362 | INIT_LIST_HEAD(&ce->e_block_list); |
363 | ce->e_cache = cache; |
364 | ce->e_queued = 0; |
365 | } |
366 | ce->e_used = 1 + MB_CACHE_WRITER; |
367 | return ce; |
368 | } |
369 | |
370 | |
371 | /* |
372 | * mb_cache_entry_insert() |
373 | * |
374 | * Inserts an entry that was allocated using mb_cache_entry_alloc() into |
375 | * the cache. After this, the cache entry can be looked up, but is not yet |
376 | * in the lru list as the caller still holds a handle to it. Returns 0 on |
377 | * success, or -EBUSY if a cache entry for that device + inode exists |
378 | * already (this may happen after a failed lookup, but when another process |
379 | * has inserted the same cache entry in the meantime). |
380 | * |
381 | * @bdev: device the cache entry belongs to |
382 | * @block: block number |
383 | * @key: lookup key |
384 | */ |
385 | int |
386 | mb_cache_entry_insert(struct mb_cache_entry *ce, struct block_device *bdev, |
387 | sector_t block, unsigned int key) |
388 | { |
389 | struct mb_cache *cache = ce->e_cache; |
390 | unsigned int bucket; |
391 | struct list_head *l; |
392 | int error = -EBUSY; |
393 | |
394 | bucket = hash_long((unsigned long)bdev + (block & 0xffffffff), |
395 | cache->c_bucket_bits); |
396 | spin_lock(&mb_cache_spinlock); |
397 | list_for_each_prev(l, &cache->c_block_hash[bucket]) { |
398 | struct mb_cache_entry *ce = |
399 | list_entry(l, struct mb_cache_entry, e_block_list); |
400 | if (ce->e_bdev == bdev && ce->e_block == block) |
401 | goto out; |
402 | } |
403 | __mb_cache_entry_unhash(ce); |
404 | ce->e_bdev = bdev; |
405 | ce->e_block = block; |
406 | list_add(&ce->e_block_list, &cache->c_block_hash[bucket]); |
407 | ce->e_index.o_key = key; |
408 | bucket = hash_long(key, cache->c_bucket_bits); |
409 | list_add(&ce->e_index.o_list, &cache->c_index_hash[bucket]); |
410 | error = 0; |
411 | out: |
412 | spin_unlock(&mb_cache_spinlock); |
413 | return error; |
414 | } |
415 | |
416 | |
417 | /* |
418 | * mb_cache_entry_release() |
419 | * |
420 | * Release a handle to a cache entry. When the last handle to a cache entry |
421 | * is released it is either freed (if it is invalid) or otherwise inserted |
422 | * in to the lru list. |
423 | */ |
424 | void |
425 | mb_cache_entry_release(struct mb_cache_entry *ce) |
426 | { |
427 | spin_lock(&mb_cache_spinlock); |
428 | __mb_cache_entry_release_unlock(ce); |
429 | } |
430 | |
431 | |
432 | /* |
433 | * mb_cache_entry_free() |
434 | * |
435 | * This is equivalent to the sequence mb_cache_entry_takeout() -- |
436 | * mb_cache_entry_release(). |
437 | */ |
438 | void |
439 | mb_cache_entry_free(struct mb_cache_entry *ce) |
440 | { |
441 | spin_lock(&mb_cache_spinlock); |
442 | mb_assert(list_empty(&ce->e_lru_list)); |
443 | __mb_cache_entry_unhash(ce); |
444 | __mb_cache_entry_release_unlock(ce); |
445 | } |
446 | |
447 | |
448 | /* |
449 | * mb_cache_entry_get() |
450 | * |
451 | * Get a cache entry by device / block number. (There can only be one entry |
452 | * in the cache per device and block.) Returns NULL if no such cache entry |
453 | * exists. The returned cache entry is locked for exclusive access ("single |
454 | * writer"). |
455 | */ |
456 | struct mb_cache_entry * |
457 | mb_cache_entry_get(struct mb_cache *cache, struct block_device *bdev, |
458 | sector_t block) |
459 | { |
460 | unsigned int bucket; |
461 | struct list_head *l; |
462 | struct mb_cache_entry *ce; |
463 | |
464 | bucket = hash_long((unsigned long)bdev + (block & 0xffffffff), |
465 | cache->c_bucket_bits); |
466 | spin_lock(&mb_cache_spinlock); |
467 | list_for_each(l, &cache->c_block_hash[bucket]) { |
468 | ce = list_entry(l, struct mb_cache_entry, e_block_list); |
469 | if (ce->e_bdev == bdev && ce->e_block == block) { |
470 | DEFINE_WAIT(wait); |
471 | |
472 | if (!list_empty(&ce->e_lru_list)) |
473 | list_del_init(&ce->e_lru_list); |
474 | |
475 | while (ce->e_used > 0) { |
476 | ce->e_queued++; |
477 | prepare_to_wait(&mb_cache_queue, &wait, |
478 | TASK_UNINTERRUPTIBLE); |
479 | spin_unlock(&mb_cache_spinlock); |
480 | schedule(); |
481 | spin_lock(&mb_cache_spinlock); |
482 | ce->e_queued--; |
483 | } |
484 | finish_wait(&mb_cache_queue, &wait); |
485 | ce->e_used += 1 + MB_CACHE_WRITER; |
486 | |
487 | if (!__mb_cache_entry_is_hashed(ce)) { |
488 | __mb_cache_entry_release_unlock(ce); |
489 | return NULL; |
490 | } |
491 | goto cleanup; |
492 | } |
493 | } |
494 | ce = NULL; |
495 | |
496 | cleanup: |
497 | spin_unlock(&mb_cache_spinlock); |
498 | return ce; |
499 | } |
500 | |
501 | #if !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0) |
502 | |
503 | static struct mb_cache_entry * |
504 | __mb_cache_entry_find(struct list_head *l, struct list_head *head, |
505 | struct block_device *bdev, unsigned int key) |
506 | { |
507 | while (l != head) { |
508 | struct mb_cache_entry *ce = |
509 | list_entry(l, struct mb_cache_entry, e_index.o_list); |
510 | if (ce->e_bdev == bdev && ce->e_index.o_key == key) { |
511 | DEFINE_WAIT(wait); |
512 | |
513 | if (!list_empty(&ce->e_lru_list)) |
514 | list_del_init(&ce->e_lru_list); |
515 | |
516 | /* Incrementing before holding the lock gives readers |
517 | priority over writers. */ |
518 | ce->e_used++; |
519 | while (ce->e_used >= MB_CACHE_WRITER) { |
520 | ce->e_queued++; |
521 | prepare_to_wait(&mb_cache_queue, &wait, |
522 | TASK_UNINTERRUPTIBLE); |
523 | spin_unlock(&mb_cache_spinlock); |
524 | schedule(); |
525 | spin_lock(&mb_cache_spinlock); |
526 | ce->e_queued--; |
527 | } |
528 | finish_wait(&mb_cache_queue, &wait); |
529 | |
530 | if (!__mb_cache_entry_is_hashed(ce)) { |
531 | __mb_cache_entry_release_unlock(ce); |
532 | spin_lock(&mb_cache_spinlock); |
533 | return ERR_PTR(-EAGAIN); |
534 | } |
535 | return ce; |
536 | } |
537 | l = l->next; |
538 | } |
539 | return NULL; |
540 | } |
541 | |
542 | |
543 | /* |
544 | * mb_cache_entry_find_first() |
545 | * |
546 | * Find the first cache entry on a given device with a certain key in |
547 | * an additional index. Additional matches can be found with |
548 | * mb_cache_entry_find_next(). Returns NULL if no match was found. The |
549 | * returned cache entry is locked for shared access ("multiple readers"). |
550 | * |
551 | * @cache: the cache to search |
552 | * @bdev: the device the cache entry should belong to |
553 | * @key: the key in the index |
554 | */ |
555 | struct mb_cache_entry * |
556 | mb_cache_entry_find_first(struct mb_cache *cache, struct block_device *bdev, |
557 | unsigned int key) |
558 | { |
559 | unsigned int bucket = hash_long(key, cache->c_bucket_bits); |
560 | struct list_head *l; |
561 | struct mb_cache_entry *ce; |
562 | |
563 | spin_lock(&mb_cache_spinlock); |
564 | l = cache->c_index_hash[bucket].next; |
565 | ce = __mb_cache_entry_find(l, &cache->c_index_hash[bucket], bdev, key); |
566 | spin_unlock(&mb_cache_spinlock); |
567 | return ce; |
568 | } |
569 | |
570 | |
571 | /* |
572 | * mb_cache_entry_find_next() |
573 | * |
574 | * Find the next cache entry on a given device with a certain key in an |
575 | * additional index. Returns NULL if no match could be found. The previous |
576 | * entry is atomatically released, so that mb_cache_entry_find_next() can |
577 | * be called like this: |
578 | * |
579 | * entry = mb_cache_entry_find_first(); |
580 | * while (entry) { |
581 | * ... |
582 | * entry = mb_cache_entry_find_next(entry, ...); |
583 | * } |
584 | * |
585 | * @prev: The previous match |
586 | * @bdev: the device the cache entry should belong to |
587 | * @key: the key in the index |
588 | */ |
589 | struct mb_cache_entry * |
590 | mb_cache_entry_find_next(struct mb_cache_entry *prev, |
591 | struct block_device *bdev, unsigned int key) |
592 | { |
593 | struct mb_cache *cache = prev->e_cache; |
594 | unsigned int bucket = hash_long(key, cache->c_bucket_bits); |
595 | struct list_head *l; |
596 | struct mb_cache_entry *ce; |
597 | |
598 | spin_lock(&mb_cache_spinlock); |
599 | l = prev->e_index.o_list.next; |
600 | ce = __mb_cache_entry_find(l, &cache->c_index_hash[bucket], bdev, key); |
601 | __mb_cache_entry_release_unlock(prev); |
602 | return ce; |
603 | } |
604 | |
605 | #endif /* !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0) */ |
606 | |
607 | static int __init init_mbcache(void) |
608 | { |
609 | register_shrinker(&mb_cache_shrinker); |
610 | return 0; |
611 | } |
612 | |
613 | static void __exit exit_mbcache(void) |
614 | { |
615 | unregister_shrinker(&mb_cache_shrinker); |
616 | } |
617 | |
618 | module_init(init_mbcache) |
619 | module_exit(exit_mbcache) |
620 | |
621 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9