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18#ifndef _LINUX_FSCACHE_CACHE_H
19#define _LINUX_FSCACHE_CACHE_H
20
21#include <linux/fscache.h>
22#include <linux/sched.h>
23#include <linux/workqueue.h>
24
25#define NR_MAXCACHES BITS_PER_LONG
26
27struct fscache_cache;
28struct fscache_cache_ops;
29struct fscache_object;
30struct fscache_operation;
31
32
33
34
35struct fscache_cache_tag {
36 struct list_head link;
37 struct fscache_cache *cache;
38 unsigned long flags;
39#define FSCACHE_TAG_RESERVED 0
40 atomic_t usage;
41 char name[0];
42};
43
44
45
46
47struct fscache_cache {
48 const struct fscache_cache_ops *ops;
49 struct fscache_cache_tag *tag;
50 struct kobject *kobj;
51 struct list_head link;
52 size_t max_index_size;
53 char identifier[36];
54
55
56 struct work_struct op_gc;
57 struct list_head object_list;
58 struct list_head op_gc_list;
59 spinlock_t object_list_lock;
60 spinlock_t op_gc_list_lock;
61 atomic_t object_count;
62 struct fscache_object *fsdef;
63 unsigned long flags;
64#define FSCACHE_IOERROR 0
65#define FSCACHE_CACHE_WITHDRAWN 1
66};
67
68extern wait_queue_head_t fscache_cache_cleared_wq;
69
70
71
72
73
74
75typedef void (*fscache_operation_release_t)(struct fscache_operation *op);
76typedef void (*fscache_operation_processor_t)(struct fscache_operation *op);
77typedef void (*fscache_operation_cancel_t)(struct fscache_operation *op);
78
79enum fscache_operation_state {
80 FSCACHE_OP_ST_BLANK,
81 FSCACHE_OP_ST_INITIALISED,
82 FSCACHE_OP_ST_PENDING,
83 FSCACHE_OP_ST_IN_PROGRESS,
84 FSCACHE_OP_ST_COMPLETE,
85 FSCACHE_OP_ST_CANCELLED,
86 FSCACHE_OP_ST_DEAD
87};
88
89struct fscache_operation {
90 struct work_struct work;
91 struct list_head pend_link;
92 struct fscache_object *object;
93
94 unsigned long flags;
95#define FSCACHE_OP_TYPE 0x000f
96#define FSCACHE_OP_ASYNC 0x0001
97#define FSCACHE_OP_MYTHREAD 0x0002
98#define FSCACHE_OP_WAITING 4
99#define FSCACHE_OP_EXCLUSIVE 5
100#define FSCACHE_OP_DEC_READ_CNT 6
101#define FSCACHE_OP_UNUSE_COOKIE 7
102#define FSCACHE_OP_KEEP_FLAGS 0x00f0
103
104 enum fscache_operation_state state;
105 atomic_t usage;
106 unsigned debug_id;
107
108
109
110
111 fscache_operation_processor_t processor;
112
113
114 fscache_operation_cancel_t cancel;
115
116
117 fscache_operation_release_t release;
118};
119
120extern atomic_t fscache_op_debug_id;
121extern void fscache_op_work_func(struct work_struct *work);
122
123extern void fscache_enqueue_operation(struct fscache_operation *);
124extern void fscache_op_complete(struct fscache_operation *, bool);
125extern void fscache_put_operation(struct fscache_operation *);
126extern void fscache_operation_init(struct fscache_operation *,
127 fscache_operation_processor_t,
128 fscache_operation_cancel_t,
129 fscache_operation_release_t);
130
131
132
133
134struct fscache_retrieval {
135 struct fscache_operation op;
136 struct fscache_cookie *cookie;
137 struct address_space *mapping;
138 fscache_rw_complete_t end_io_func;
139 void *context;
140 struct list_head to_do;
141 unsigned long start_time;
142 atomic_t n_pages;
143};
144
145typedef int (*fscache_page_retrieval_func_t)(struct fscache_retrieval *op,
146 struct page *page,
147 gfp_t gfp);
148
149typedef int (*fscache_pages_retrieval_func_t)(struct fscache_retrieval *op,
150 struct list_head *pages,
151 unsigned *nr_pages,
152 gfp_t gfp);
153
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158
159
160static inline
161struct fscache_retrieval *fscache_get_retrieval(struct fscache_retrieval *op)
162{
163 atomic_inc(&op->op.usage);
164 return op;
165}
166
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171
172
173static inline void fscache_enqueue_retrieval(struct fscache_retrieval *op)
174{
175 fscache_enqueue_operation(&op->op);
176}
177
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180
181
182
183static inline void fscache_retrieval_complete(struct fscache_retrieval *op,
184 int n_pages)
185{
186 atomic_sub(n_pages, &op->n_pages);
187 if (atomic_read(&op->n_pages) <= 0)
188 fscache_op_complete(&op->op, true);
189}
190
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193
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195
196
197static inline void fscache_put_retrieval(struct fscache_retrieval *op)
198{
199 fscache_put_operation(&op->op);
200}
201
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208
209struct fscache_storage {
210 struct fscache_operation op;
211 pgoff_t store_limit;
212};
213
214
215
216
217struct fscache_cache_ops {
218
219 const char *name;
220
221
222 struct fscache_object *(*alloc_object)(struct fscache_cache *cache,
223 struct fscache_cookie *cookie);
224
225
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227
228 int (*lookup_object)(struct fscache_object *object);
229
230
231 void (*lookup_complete)(struct fscache_object *object);
232
233
234 struct fscache_object *(*grab_object)(struct fscache_object *object);
235
236
237 int (*pin_object)(struct fscache_object *object);
238
239
240 void (*unpin_object)(struct fscache_object *object);
241
242
243
244 bool (*check_consistency)(struct fscache_operation *op);
245
246
247 void (*update_object)(struct fscache_object *object);
248
249
250 void (*invalidate_object)(struct fscache_operation *op);
251
252
253
254 void (*drop_object)(struct fscache_object *object);
255
256
257 void (*put_object)(struct fscache_object *object);
258
259
260 void (*sync_cache)(struct fscache_cache *cache);
261
262
263
264 int (*attr_changed)(struct fscache_object *object);
265
266
267 int (*reserve_space)(struct fscache_object *object, loff_t i_size);
268
269
270
271 fscache_page_retrieval_func_t read_or_alloc_page;
272
273
274
275 fscache_pages_retrieval_func_t read_or_alloc_pages;
276
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278
279 fscache_page_retrieval_func_t allocate_page;
280
281
282
283 fscache_pages_retrieval_func_t allocate_pages;
284
285
286 int (*write_page)(struct fscache_storage *op, struct page *page);
287
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290
291
292 void (*uncache_page)(struct fscache_object *object,
293 struct page *page);
294
295
296 void (*dissociate_pages)(struct fscache_cache *cache);
297};
298
299extern struct fscache_cookie fscache_fsdef_index;
300
301
302
303
304enum {
305 FSCACHE_OBJECT_EV_NEW_CHILD,
306 FSCACHE_OBJECT_EV_PARENT_READY,
307 FSCACHE_OBJECT_EV_UPDATE,
308 FSCACHE_OBJECT_EV_INVALIDATE,
309 FSCACHE_OBJECT_EV_CLEARED,
310 FSCACHE_OBJECT_EV_ERROR,
311 FSCACHE_OBJECT_EV_KILL,
312 NR_FSCACHE_OBJECT_EVENTS
313};
314
315#define FSCACHE_OBJECT_EVENTS_MASK ((1UL << NR_FSCACHE_OBJECT_EVENTS) - 1)
316
317
318
319
320struct fscache_transition {
321 unsigned long events;
322 const struct fscache_state *transit_to;
323};
324
325struct fscache_state {
326 char name[24];
327 char short_name[8];
328 const struct fscache_state *(*work)(struct fscache_object *object,
329 int event);
330 const struct fscache_transition transitions[];
331};
332
333
334
335
336struct fscache_object {
337 const struct fscache_state *state;
338 const struct fscache_transition *oob_table;
339 int debug_id;
340 int n_children;
341 int n_ops;
342 int n_obj_ops;
343 int n_in_progress;
344 int n_exclusive;
345 atomic_t n_reads;
346 spinlock_t lock;
347
348 unsigned long lookup_jif;
349 unsigned long oob_event_mask;
350 unsigned long event_mask;
351 unsigned long events;
352
353
354 unsigned long flags;
355#define FSCACHE_OBJECT_LOCK 0
356#define FSCACHE_OBJECT_PENDING_WRITE 1
357#define FSCACHE_OBJECT_WAITING 2
358#define FSCACHE_OBJECT_IS_LIVE 3
359#define FSCACHE_OBJECT_IS_LOOKED_UP 4
360#define FSCACHE_OBJECT_IS_AVAILABLE 5
361#define FSCACHE_OBJECT_RETIRED 6
362#define FSCACHE_OBJECT_KILLED_BY_CACHE 7
363
364 struct list_head cache_link;
365 struct hlist_node cookie_link;
366 struct fscache_cache *cache;
367 struct fscache_cookie *cookie;
368 struct fscache_object *parent;
369 struct work_struct work;
370 struct list_head dependents;
371 struct list_head dep_link;
372 struct list_head pending_ops;
373#ifdef CONFIG_FSCACHE_OBJECT_LIST
374 struct rb_node objlist_link;
375#endif
376 pgoff_t store_limit;
377 loff_t store_limit_l;
378};
379
380extern void fscache_object_init(struct fscache_object *, struct fscache_cookie *,
381 struct fscache_cache *);
382extern void fscache_object_destroy(struct fscache_object *);
383
384extern void fscache_object_lookup_negative(struct fscache_object *object);
385extern void fscache_obtained_object(struct fscache_object *object);
386
387static inline bool fscache_object_is_live(struct fscache_object *object)
388{
389 return test_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
390}
391
392static inline bool fscache_object_is_dying(struct fscache_object *object)
393{
394 return !fscache_object_is_live(object);
395}
396
397static inline bool fscache_object_is_available(struct fscache_object *object)
398{
399 return test_bit(FSCACHE_OBJECT_IS_AVAILABLE, &object->flags);
400}
401
402static inline bool fscache_cache_is_broken(struct fscache_object *object)
403{
404 return test_bit(FSCACHE_IOERROR, &object->cache->flags);
405}
406
407static inline bool fscache_object_is_active(struct fscache_object *object)
408{
409 return fscache_object_is_available(object) &&
410 fscache_object_is_live(object) &&
411 !fscache_cache_is_broken(object);
412}
413
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418
419
420static inline void fscache_object_destroyed(struct fscache_cache *cache)
421{
422 if (atomic_dec_and_test(&cache->object_count))
423 wake_up_all(&fscache_cache_cleared_wq);
424}
425
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431
432
433static inline void fscache_object_lookup_error(struct fscache_object *object)
434{
435 set_bit(FSCACHE_OBJECT_EV_ERROR, &object->events);
436}
437
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447
448
449static inline
450void fscache_set_store_limit(struct fscache_object *object, loff_t i_size)
451{
452 object->store_limit_l = i_size;
453 object->store_limit = i_size >> PAGE_SHIFT;
454 if (i_size & ~PAGE_MASK)
455 object->store_limit++;
456}
457
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465
466
467static inline void fscache_end_io(struct fscache_retrieval *op,
468 struct page *page, int error)
469{
470 op->end_io_func(page, op->context, error);
471}
472
473static inline void __fscache_use_cookie(struct fscache_cookie *cookie)
474{
475 atomic_inc(&cookie->n_active);
476}
477
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483
484
485static inline bool fscache_use_cookie(struct fscache_object *object)
486{
487 struct fscache_cookie *cookie = object->cookie;
488 return atomic_inc_not_zero(&cookie->n_active) != 0;
489}
490
491static inline bool __fscache_unuse_cookie(struct fscache_cookie *cookie)
492{
493 return atomic_dec_and_test(&cookie->n_active);
494}
495
496static inline void __fscache_wake_unused_cookie(struct fscache_cookie *cookie)
497{
498 wake_up_atomic_t(&cookie->n_active);
499}
500
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505
506
507
508static inline void fscache_unuse_cookie(struct fscache_object *object)
509{
510 struct fscache_cookie *cookie = object->cookie;
511 if (__fscache_unuse_cookie(cookie))
512 __fscache_wake_unused_cookie(cookie);
513}
514
515
516
517
518extern __printf(3, 4)
519void fscache_init_cache(struct fscache_cache *cache,
520 const struct fscache_cache_ops *ops,
521 const char *idfmt, ...);
522
523extern int fscache_add_cache(struct fscache_cache *cache,
524 struct fscache_object *fsdef,
525 const char *tagname);
526extern void fscache_withdraw_cache(struct fscache_cache *cache);
527
528extern void fscache_io_error(struct fscache_cache *cache);
529
530extern void fscache_mark_page_cached(struct fscache_retrieval *op,
531 struct page *page);
532
533extern void fscache_mark_pages_cached(struct fscache_retrieval *op,
534 struct pagevec *pagevec);
535
536extern bool fscache_object_sleep_till_congested(signed long *timeoutp);
537
538extern enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
539 const void *data,
540 uint16_t datalen);
541
542extern void fscache_object_retrying_stale(struct fscache_object *object);
543
544enum fscache_why_object_killed {
545 FSCACHE_OBJECT_IS_STALE,
546 FSCACHE_OBJECT_NO_SPACE,
547 FSCACHE_OBJECT_WAS_RETIRED,
548 FSCACHE_OBJECT_WAS_CULLED,
549};
550extern void fscache_object_mark_killed(struct fscache_object *object,
551 enum fscache_why_object_killed why);
552
553#endif
554