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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
154
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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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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
191
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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
226
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#define FSCACHE_OBJECT_RUN_AFTER_DEAD 8
364
365 struct list_head cache_link;
366 struct hlist_node cookie_link;
367 struct fscache_cache *cache;
368 struct fscache_cookie *cookie;
369 struct fscache_object *parent;
370 struct work_struct work;
371 struct list_head dependents;
372 struct list_head dep_link;
373 struct list_head pending_ops;
374#ifdef CONFIG_FSCACHE_OBJECT_LIST
375 struct rb_node objlist_link;
376#endif
377 pgoff_t store_limit;
378 loff_t store_limit_l;
379};
380
381extern void fscache_object_init(struct fscache_object *, struct fscache_cookie *,
382 struct fscache_cache *);
383extern void fscache_object_destroy(struct fscache_object *);
384
385extern void fscache_object_lookup_negative(struct fscache_object *object);
386extern void fscache_obtained_object(struct fscache_object *object);
387
388static inline bool fscache_object_is_live(struct fscache_object *object)
389{
390 return test_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
391}
392
393static inline bool fscache_object_is_dying(struct fscache_object *object)
394{
395 return !fscache_object_is_live(object);
396}
397
398static inline bool fscache_object_is_available(struct fscache_object *object)
399{
400 return test_bit(FSCACHE_OBJECT_IS_AVAILABLE, &object->flags);
401}
402
403static inline bool fscache_cache_is_broken(struct fscache_object *object)
404{
405 return test_bit(FSCACHE_IOERROR, &object->cache->flags);
406}
407
408static inline bool fscache_object_is_active(struct fscache_object *object)
409{
410 return fscache_object_is_available(object) &&
411 fscache_object_is_live(object) &&
412 !fscache_cache_is_broken(object);
413}
414
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418
419
420
421static inline void fscache_object_destroyed(struct fscache_cache *cache)
422{
423 if (atomic_dec_and_test(&cache->object_count))
424 wake_up_all(&fscache_cache_cleared_wq);
425}
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430
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432
433
434static inline void fscache_object_lookup_error(struct fscache_object *object)
435{
436 set_bit(FSCACHE_OBJECT_EV_ERROR, &object->events);
437}
438
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448
449
450static inline
451void fscache_set_store_limit(struct fscache_object *object, loff_t i_size)
452{
453 object->store_limit_l = i_size;
454 object->store_limit = i_size >> PAGE_SHIFT;
455 if (i_size & ~PAGE_MASK)
456 object->store_limit++;
457}
458
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465
466
467
468static inline void fscache_end_io(struct fscache_retrieval *op,
469 struct page *page, int error)
470{
471 op->end_io_func(page, op->context, error);
472}
473
474static inline void __fscache_use_cookie(struct fscache_cookie *cookie)
475{
476 atomic_inc(&cookie->n_active);
477}
478
479
480
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483
484
485
486static inline bool fscache_use_cookie(struct fscache_object *object)
487{
488 struct fscache_cookie *cookie = object->cookie;
489 return atomic_inc_not_zero(&cookie->n_active) != 0;
490}
491
492static inline bool __fscache_unuse_cookie(struct fscache_cookie *cookie)
493{
494 return atomic_dec_and_test(&cookie->n_active);
495}
496
497static inline void __fscache_wake_unused_cookie(struct fscache_cookie *cookie)
498{
499 wake_up_atomic_t(&cookie->n_active);
500}
501
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506
507
508
509static inline void fscache_unuse_cookie(struct fscache_object *object)
510{
511 struct fscache_cookie *cookie = object->cookie;
512 if (__fscache_unuse_cookie(cookie))
513 __fscache_wake_unused_cookie(cookie);
514}
515
516
517
518
519extern __printf(3, 4)
520void fscache_init_cache(struct fscache_cache *cache,
521 const struct fscache_cache_ops *ops,
522 const char *idfmt, ...);
523
524extern int fscache_add_cache(struct fscache_cache *cache,
525 struct fscache_object *fsdef,
526 const char *tagname);
527extern void fscache_withdraw_cache(struct fscache_cache *cache);
528
529extern void fscache_io_error(struct fscache_cache *cache);
530
531extern void fscache_mark_page_cached(struct fscache_retrieval *op,
532 struct page *page);
533
534extern void fscache_mark_pages_cached(struct fscache_retrieval *op,
535 struct pagevec *pagevec);
536
537extern bool fscache_object_sleep_till_congested(signed long *timeoutp);
538
539extern enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
540 const void *data,
541 uint16_t datalen);
542
543extern void fscache_object_retrying_stale(struct fscache_object *object);
544
545enum fscache_why_object_killed {
546 FSCACHE_OBJECT_IS_STALE,
547 FSCACHE_OBJECT_NO_SPACE,
548 FSCACHE_OBJECT_WAS_RETIRED,
549 FSCACHE_OBJECT_WAS_CULLED,
550};
551extern void fscache_object_mark_killed(struct fscache_object *object,
552 enum fscache_why_object_killed why);
553
554#endif
555