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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
32enum fscache_obj_ref_trace {
33 fscache_obj_get_add_to_deps,
34 fscache_obj_get_queue,
35 fscache_obj_put_alloc_fail,
36 fscache_obj_put_attach_fail,
37 fscache_obj_put_drop_obj,
38 fscache_obj_put_enq_dep,
39 fscache_obj_put_queue,
40 fscache_obj_put_work,
41 fscache_obj_ref__nr_traces
42};
43
44
45
46
47struct fscache_cache_tag {
48 struct list_head link;
49 struct fscache_cache *cache;
50 unsigned long flags;
51#define FSCACHE_TAG_RESERVED 0
52 atomic_t usage;
53 char name[0];
54};
55
56
57
58
59struct fscache_cache {
60 const struct fscache_cache_ops *ops;
61 struct fscache_cache_tag *tag;
62 struct kobject *kobj;
63 struct list_head link;
64 size_t max_index_size;
65 char identifier[36];
66
67
68 struct work_struct op_gc;
69 struct list_head object_list;
70 struct list_head op_gc_list;
71 spinlock_t object_list_lock;
72 spinlock_t op_gc_list_lock;
73 atomic_t object_count;
74 struct fscache_object *fsdef;
75 unsigned long flags;
76#define FSCACHE_IOERROR 0
77#define FSCACHE_CACHE_WITHDRAWN 1
78};
79
80extern wait_queue_head_t fscache_cache_cleared_wq;
81
82
83
84
85
86
87typedef void (*fscache_operation_release_t)(struct fscache_operation *op);
88typedef void (*fscache_operation_processor_t)(struct fscache_operation *op);
89typedef void (*fscache_operation_cancel_t)(struct fscache_operation *op);
90
91enum fscache_operation_state {
92 FSCACHE_OP_ST_BLANK,
93 FSCACHE_OP_ST_INITIALISED,
94 FSCACHE_OP_ST_PENDING,
95 FSCACHE_OP_ST_IN_PROGRESS,
96 FSCACHE_OP_ST_COMPLETE,
97 FSCACHE_OP_ST_CANCELLED,
98 FSCACHE_OP_ST_DEAD
99};
100
101struct fscache_operation {
102 struct work_struct work;
103 struct list_head pend_link;
104 struct fscache_object *object;
105
106 unsigned long flags;
107#define FSCACHE_OP_TYPE 0x000f
108#define FSCACHE_OP_ASYNC 0x0001
109#define FSCACHE_OP_MYTHREAD 0x0002
110#define FSCACHE_OP_WAITING 4
111#define FSCACHE_OP_EXCLUSIVE 5
112#define FSCACHE_OP_DEC_READ_CNT 6
113#define FSCACHE_OP_UNUSE_COOKIE 7
114#define FSCACHE_OP_KEEP_FLAGS 0x00f0
115
116 enum fscache_operation_state state;
117 atomic_t usage;
118 unsigned debug_id;
119
120
121
122
123 fscache_operation_processor_t processor;
124
125
126 fscache_operation_cancel_t cancel;
127
128
129 fscache_operation_release_t release;
130};
131
132extern atomic_t fscache_op_debug_id;
133extern void fscache_op_work_func(struct work_struct *work);
134
135extern void fscache_enqueue_operation(struct fscache_operation *);
136extern void fscache_op_complete(struct fscache_operation *, bool);
137extern void fscache_put_operation(struct fscache_operation *);
138extern void fscache_operation_init(struct fscache_cookie *,
139 struct fscache_operation *,
140 fscache_operation_processor_t,
141 fscache_operation_cancel_t,
142 fscache_operation_release_t);
143
144
145
146
147struct fscache_retrieval {
148 struct fscache_operation op;
149 struct fscache_cookie *cookie;
150 struct address_space *mapping;
151 fscache_rw_complete_t end_io_func;
152 void *context;
153 struct list_head to_do;
154 unsigned long start_time;
155 atomic_t n_pages;
156};
157
158typedef int (*fscache_page_retrieval_func_t)(struct fscache_retrieval *op,
159 struct page *page,
160 gfp_t gfp);
161
162typedef int (*fscache_pages_retrieval_func_t)(struct fscache_retrieval *op,
163 struct list_head *pages,
164 unsigned *nr_pages,
165 gfp_t gfp);
166
167
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169
170
171
172
173static inline
174struct fscache_retrieval *fscache_get_retrieval(struct fscache_retrieval *op)
175{
176 atomic_inc(&op->op.usage);
177 return op;
178}
179
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181
182
183
184
185
186static inline void fscache_enqueue_retrieval(struct fscache_retrieval *op)
187{
188 fscache_enqueue_operation(&op->op);
189}
190
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193
194
195
196static inline void fscache_retrieval_complete(struct fscache_retrieval *op,
197 int n_pages)
198{
199 if (atomic_sub_return_relaxed(n_pages, &op->n_pages) <= 0)
200 fscache_op_complete(&op->op, false);
201}
202
203
204
205
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207
208
209static inline void fscache_put_retrieval(struct fscache_retrieval *op)
210{
211 fscache_put_operation(&op->op);
212}
213
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219
220
221struct fscache_storage {
222 struct fscache_operation op;
223 pgoff_t store_limit;
224};
225
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227
228
229struct fscache_cache_ops {
230
231 const char *name;
232
233
234 struct fscache_object *(*alloc_object)(struct fscache_cache *cache,
235 struct fscache_cookie *cookie);
236
237
238
239
240 int (*lookup_object)(struct fscache_object *object);
241
242
243 void (*lookup_complete)(struct fscache_object *object);
244
245
246 struct fscache_object *(*grab_object)(struct fscache_object *object,
247 enum fscache_obj_ref_trace why);
248
249
250 int (*pin_object)(struct fscache_object *object);
251
252
253 void (*unpin_object)(struct fscache_object *object);
254
255
256
257 int (*check_consistency)(struct fscache_operation *op);
258
259
260 void (*update_object)(struct fscache_object *object);
261
262
263 void (*invalidate_object)(struct fscache_operation *op);
264
265
266
267 void (*drop_object)(struct fscache_object *object);
268
269
270 void (*put_object)(struct fscache_object *object,
271 enum fscache_obj_ref_trace why);
272
273
274 void (*sync_cache)(struct fscache_cache *cache);
275
276
277
278 int (*attr_changed)(struct fscache_object *object);
279
280
281 int (*reserve_space)(struct fscache_object *object, loff_t i_size);
282
283
284
285 fscache_page_retrieval_func_t read_or_alloc_page;
286
287
288
289 fscache_pages_retrieval_func_t read_or_alloc_pages;
290
291
292
293 fscache_page_retrieval_func_t allocate_page;
294
295
296
297 fscache_pages_retrieval_func_t allocate_pages;
298
299
300 int (*write_page)(struct fscache_storage *op, struct page *page);
301
302
303
304
305
306 void (*uncache_page)(struct fscache_object *object,
307 struct page *page);
308
309
310 void (*dissociate_pages)(struct fscache_cache *cache);
311};
312
313extern struct fscache_cookie fscache_fsdef_index;
314
315
316
317
318enum {
319 FSCACHE_OBJECT_EV_NEW_CHILD,
320 FSCACHE_OBJECT_EV_PARENT_READY,
321 FSCACHE_OBJECT_EV_UPDATE,
322 FSCACHE_OBJECT_EV_INVALIDATE,
323 FSCACHE_OBJECT_EV_CLEARED,
324 FSCACHE_OBJECT_EV_ERROR,
325 FSCACHE_OBJECT_EV_KILL,
326 NR_FSCACHE_OBJECT_EVENTS
327};
328
329#define FSCACHE_OBJECT_EVENTS_MASK ((1UL << NR_FSCACHE_OBJECT_EVENTS) - 1)
330
331
332
333
334struct fscache_transition {
335 unsigned long events;
336 const struct fscache_state *transit_to;
337};
338
339struct fscache_state {
340 char name[24];
341 char short_name[8];
342 const struct fscache_state *(*work)(struct fscache_object *object,
343 int event);
344 const struct fscache_transition transitions[];
345};
346
347
348
349
350struct fscache_object {
351 const struct fscache_state *state;
352 const struct fscache_transition *oob_table;
353 int debug_id;
354 int n_children;
355 int n_ops;
356 int n_obj_ops;
357 int n_in_progress;
358 int n_exclusive;
359 atomic_t n_reads;
360 spinlock_t lock;
361
362 unsigned long lookup_jif;
363 unsigned long oob_event_mask;
364 unsigned long event_mask;
365 unsigned long events;
366
367
368 unsigned long flags;
369#define FSCACHE_OBJECT_LOCK 0
370#define FSCACHE_OBJECT_PENDING_WRITE 1
371#define FSCACHE_OBJECT_WAITING 2
372#define FSCACHE_OBJECT_IS_LIVE 3
373#define FSCACHE_OBJECT_IS_LOOKED_UP 4
374#define FSCACHE_OBJECT_IS_AVAILABLE 5
375#define FSCACHE_OBJECT_RETIRED 6
376#define FSCACHE_OBJECT_KILLED_BY_CACHE 7
377#define FSCACHE_OBJECT_RUN_AFTER_DEAD 8
378
379 struct list_head cache_link;
380 struct hlist_node cookie_link;
381 struct fscache_cache *cache;
382 struct fscache_cookie *cookie;
383 struct fscache_object *parent;
384 struct work_struct work;
385 struct list_head dependents;
386 struct list_head dep_link;
387 struct list_head pending_ops;
388#ifdef CONFIG_FSCACHE_OBJECT_LIST
389 struct rb_node objlist_link;
390#endif
391 pgoff_t store_limit;
392 loff_t store_limit_l;
393};
394
395extern void fscache_object_init(struct fscache_object *, struct fscache_cookie *,
396 struct fscache_cache *);
397extern void fscache_object_destroy(struct fscache_object *);
398
399extern void fscache_object_lookup_negative(struct fscache_object *object);
400extern void fscache_obtained_object(struct fscache_object *object);
401
402static inline bool fscache_object_is_live(struct fscache_object *object)
403{
404 return test_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
405}
406
407static inline bool fscache_object_is_dying(struct fscache_object *object)
408{
409 return !fscache_object_is_live(object);
410}
411
412static inline bool fscache_object_is_available(struct fscache_object *object)
413{
414 return test_bit(FSCACHE_OBJECT_IS_AVAILABLE, &object->flags);
415}
416
417static inline bool fscache_cache_is_broken(struct fscache_object *object)
418{
419 return test_bit(FSCACHE_IOERROR, &object->cache->flags);
420}
421
422static inline bool fscache_object_is_active(struct fscache_object *object)
423{
424 return fscache_object_is_available(object) &&
425 fscache_object_is_live(object) &&
426 !fscache_cache_is_broken(object);
427}
428
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432
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434
435static inline void fscache_object_destroyed(struct fscache_cache *cache)
436{
437 if (atomic_dec_and_test(&cache->object_count))
438 wake_up_all(&fscache_cache_cleared_wq);
439}
440
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443
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446
447
448static inline void fscache_object_lookup_error(struct fscache_object *object)
449{
450 set_bit(FSCACHE_OBJECT_EV_ERROR, &object->events);
451}
452
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462
463
464static inline
465void fscache_set_store_limit(struct fscache_object *object, loff_t i_size)
466{
467 object->store_limit_l = i_size;
468 object->store_limit = i_size >> PAGE_SHIFT;
469 if (i_size & ~PAGE_MASK)
470 object->store_limit++;
471}
472
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474
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480
481
482static inline void fscache_end_io(struct fscache_retrieval *op,
483 struct page *page, int error)
484{
485 op->end_io_func(page, op->context, error);
486}
487
488static inline void __fscache_use_cookie(struct fscache_cookie *cookie)
489{
490 atomic_inc(&cookie->n_active);
491}
492
493
494
495
496
497
498
499
500static inline bool fscache_use_cookie(struct fscache_object *object)
501{
502 struct fscache_cookie *cookie = object->cookie;
503 return atomic_inc_not_zero(&cookie->n_active) != 0;
504}
505
506static inline bool __fscache_unuse_cookie(struct fscache_cookie *cookie)
507{
508 return atomic_dec_and_test(&cookie->n_active);
509}
510
511static inline void __fscache_wake_unused_cookie(struct fscache_cookie *cookie)
512{
513 wake_up_var(&cookie->n_active);
514}
515
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519
520
521
522
523static inline void fscache_unuse_cookie(struct fscache_object *object)
524{
525 struct fscache_cookie *cookie = object->cookie;
526 if (__fscache_unuse_cookie(cookie))
527 __fscache_wake_unused_cookie(cookie);
528}
529
530
531
532
533extern __printf(3, 4)
534void fscache_init_cache(struct fscache_cache *cache,
535 const struct fscache_cache_ops *ops,
536 const char *idfmt, ...);
537
538extern int fscache_add_cache(struct fscache_cache *cache,
539 struct fscache_object *fsdef,
540 const char *tagname);
541extern void fscache_withdraw_cache(struct fscache_cache *cache);
542
543extern void fscache_io_error(struct fscache_cache *cache);
544
545extern void fscache_mark_page_cached(struct fscache_retrieval *op,
546 struct page *page);
547
548extern void fscache_mark_pages_cached(struct fscache_retrieval *op,
549 struct pagevec *pagevec);
550
551extern bool fscache_object_sleep_till_congested(signed long *timeoutp);
552
553extern enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
554 const void *data,
555 uint16_t datalen,
556 loff_t object_size);
557
558extern void fscache_object_retrying_stale(struct fscache_object *object);
559
560enum fscache_why_object_killed {
561 FSCACHE_OBJECT_IS_STALE,
562 FSCACHE_OBJECT_NO_SPACE,
563 FSCACHE_OBJECT_WAS_RETIRED,
564 FSCACHE_OBJECT_WAS_CULLED,
565};
566extern void fscache_object_mark_killed(struct fscache_object *object,
567 enum fscache_why_object_killed why);
568
569#endif
570