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0dfc41d1 DH |
1 | /* General filesystem caching backing cache interface |
2 | * | |
3 | * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | * | |
11 | * NOTE!!! See: | |
12 | * | |
13 | * Documentation/filesystems/caching/backend-api.txt | |
14 | * | |
15 | * for a description of the cache backend interface declared here. | |
16 | */ | |
17 | ||
18 | #ifndef _LINUX_FSCACHE_CACHE_H | |
19 | #define _LINUX_FSCACHE_CACHE_H | |
20 | ||
21 | #include <linux/fscache.h> | |
22 | #include <linux/sched.h> | |
8b8edefa | 23 | #include <linux/workqueue.h> |
0dfc41d1 DH |
24 | |
25 | #define NR_MAXCACHES BITS_PER_LONG | |
26 | ||
27 | struct fscache_cache; | |
28 | struct fscache_cache_ops; | |
29 | struct fscache_object; | |
30 | struct fscache_operation; | |
31 | ||
0dfc41d1 DH |
32 | /* |
33 | * cache tag definition | |
34 | */ | |
35 | struct fscache_cache_tag { | |
36 | struct list_head link; | |
37 | struct fscache_cache *cache; /* cache referred to by this tag */ | |
38 | unsigned long flags; | |
39 | #define FSCACHE_TAG_RESERVED 0 /* T if tag is reserved for a cache */ | |
40 | atomic_t usage; | |
41 | char name[0]; /* tag name */ | |
42 | }; | |
43 | ||
44 | /* | |
45 | * cache definition | |
46 | */ | |
47 | struct fscache_cache { | |
48 | const struct fscache_cache_ops *ops; | |
49 | struct fscache_cache_tag *tag; /* tag representing this cache */ | |
50 | struct kobject *kobj; /* system representation of this cache */ | |
51 | struct list_head link; /* link in list of caches */ | |
52 | size_t max_index_size; /* maximum size of index data */ | |
53 | char identifier[36]; /* cache label */ | |
54 | ||
55 | /* node management */ | |
56 | struct work_struct op_gc; /* operation garbage collector */ | |
57 | struct list_head object_list; /* list of data/index objects */ | |
58 | struct list_head op_gc_list; /* list of ops to be deleted */ | |
59 | spinlock_t object_list_lock; | |
60 | spinlock_t op_gc_list_lock; | |
61 | atomic_t object_count; /* no. of live objects in this cache */ | |
62 | struct fscache_object *fsdef; /* object for the fsdef index */ | |
63 | unsigned long flags; | |
64 | #define FSCACHE_IOERROR 0 /* cache stopped on I/O error */ | |
65 | #define FSCACHE_CACHE_WITHDRAWN 1 /* cache has been withdrawn */ | |
66 | }; | |
67 | ||
68 | extern wait_queue_head_t fscache_cache_cleared_wq; | |
69 | ||
70 | /* | |
71 | * operation to be applied to a cache object | |
72 | * - retrieval initiation operations are done in the context of the process | |
73 | * that issued them, and not in an async thread pool | |
74 | */ | |
75 | typedef void (*fscache_operation_release_t)(struct fscache_operation *op); | |
76 | typedef void (*fscache_operation_processor_t)(struct fscache_operation *op); | |
77 | ||
78 | struct fscache_operation { | |
8af7c124 | 79 | struct work_struct work; /* record for async ops */ |
0dfc41d1 DH |
80 | struct list_head pend_link; /* link in object->pending_ops */ |
81 | struct fscache_object *object; /* object to be operated upon */ | |
82 | ||
83 | unsigned long flags; | |
84 | #define FSCACHE_OP_TYPE 0x000f /* operation type */ | |
8af7c124 TH |
85 | #define FSCACHE_OP_ASYNC 0x0001 /* - async op, processor may sleep for disk */ |
86 | #define FSCACHE_OP_MYTHREAD 0x0002 /* - processing is done be issuing thread, not pool */ | |
0dfc41d1 DH |
87 | #define FSCACHE_OP_WAITING 4 /* cleared when op is woken */ |
88 | #define FSCACHE_OP_EXCLUSIVE 5 /* exclusive op, other ops must wait */ | |
89 | #define FSCACHE_OP_DEAD 6 /* op is now dead */ | |
4fbf4291 DH |
90 | #define FSCACHE_OP_DEC_READ_CNT 7 /* decrement object->n_reads on destruction */ |
91 | #define FSCACHE_OP_KEEP_FLAGS 0xc0 /* flags to keep when repurposing an op */ | |
0dfc41d1 DH |
92 | |
93 | atomic_t usage; | |
94 | unsigned debug_id; /* debugging ID */ | |
95 | ||
96 | /* operation processor callback | |
97 | * - can be NULL if FSCACHE_OP_WAITING is going to be used to perform | |
98 | * the op in a non-pool thread */ | |
99 | fscache_operation_processor_t processor; | |
100 | ||
101 | /* operation releaser */ | |
102 | fscache_operation_release_t release; | |
440f0aff | 103 | |
8af7c124 TH |
104 | #ifdef CONFIG_WORKQUEUE_DEBUGFS |
105 | struct work_struct put_work; /* work to delay operation put */ | |
440f0aff DH |
106 | const char *name; /* operation name */ |
107 | const char *state; /* operation state */ | |
108 | #define fscache_set_op_name(OP, N) do { (OP)->name = (N); } while(0) | |
109 | #define fscache_set_op_state(OP, S) do { (OP)->state = (S); } while(0) | |
110 | #else | |
111 | #define fscache_set_op_name(OP, N) do { } while(0) | |
112 | #define fscache_set_op_state(OP, S) do { } while(0) | |
113 | #endif | |
0dfc41d1 DH |
114 | }; |
115 | ||
116 | extern atomic_t fscache_op_debug_id; | |
8af7c124 | 117 | extern void fscache_op_work_func(struct work_struct *work); |
0dfc41d1 DH |
118 | |
119 | extern void fscache_enqueue_operation(struct fscache_operation *); | |
120 | extern void fscache_put_operation(struct fscache_operation *); | |
121 | ||
122 | /** | |
123 | * fscache_operation_init - Do basic initialisation of an operation | |
124 | * @op: The operation to initialise | |
125 | * @release: The release function to assign | |
126 | * | |
127 | * Do basic initialisation of an operation. The caller must still set flags, | |
8af7c124 | 128 | * object and processor if needed. |
0dfc41d1 DH |
129 | */ |
130 | static inline void fscache_operation_init(struct fscache_operation *op, | |
8af7c124 TH |
131 | fscache_operation_processor_t processor, |
132 | fscache_operation_release_t release) | |
0dfc41d1 | 133 | { |
8af7c124 | 134 | INIT_WORK(&op->work, fscache_op_work_func); |
0dfc41d1 DH |
135 | atomic_set(&op->usage, 1); |
136 | op->debug_id = atomic_inc_return(&fscache_op_debug_id); | |
8af7c124 | 137 | op->processor = processor; |
0dfc41d1 DH |
138 | op->release = release; |
139 | INIT_LIST_HEAD(&op->pend_link); | |
440f0aff | 140 | fscache_set_op_state(op, "Init"); |
0dfc41d1 DH |
141 | } |
142 | ||
0dfc41d1 DH |
143 | /* |
144 | * data read operation | |
145 | */ | |
146 | struct fscache_retrieval { | |
147 | struct fscache_operation op; | |
148 | struct address_space *mapping; /* netfs pages */ | |
149 | fscache_rw_complete_t end_io_func; /* function to call on I/O completion */ | |
150 | void *context; /* netfs read context (pinned) */ | |
151 | struct list_head to_do; /* list of things to be done by the backend */ | |
152 | unsigned long start_time; /* time at which retrieval started */ | |
153 | }; | |
154 | ||
155 | typedef int (*fscache_page_retrieval_func_t)(struct fscache_retrieval *op, | |
156 | struct page *page, | |
157 | gfp_t gfp); | |
158 | ||
159 | typedef int (*fscache_pages_retrieval_func_t)(struct fscache_retrieval *op, | |
160 | struct list_head *pages, | |
161 | unsigned *nr_pages, | |
162 | gfp_t gfp); | |
163 | ||
164 | /** | |
165 | * fscache_get_retrieval - Get an extra reference on a retrieval operation | |
166 | * @op: The retrieval operation to get a reference on | |
167 | * | |
168 | * Get an extra reference on a retrieval operation. | |
169 | */ | |
170 | static inline | |
171 | struct fscache_retrieval *fscache_get_retrieval(struct fscache_retrieval *op) | |
172 | { | |
173 | atomic_inc(&op->op.usage); | |
174 | return op; | |
175 | } | |
176 | ||
177 | /** | |
178 | * fscache_enqueue_retrieval - Enqueue a retrieval operation for processing | |
179 | * @op: The retrieval operation affected | |
180 | * | |
181 | * Enqueue a retrieval operation for processing by the FS-Cache thread pool. | |
182 | */ | |
183 | static inline void fscache_enqueue_retrieval(struct fscache_retrieval *op) | |
184 | { | |
185 | fscache_enqueue_operation(&op->op); | |
186 | } | |
187 | ||
188 | /** | |
189 | * fscache_put_retrieval - Drop a reference to a retrieval operation | |
190 | * @op: The retrieval operation affected | |
191 | * | |
192 | * Drop a reference to a retrieval operation. | |
193 | */ | |
194 | static inline void fscache_put_retrieval(struct fscache_retrieval *op) | |
195 | { | |
196 | fscache_put_operation(&op->op); | |
197 | } | |
198 | ||
199 | /* | |
200 | * cached page storage work item | |
201 | * - used to do three things: | |
202 | * - batch writes to the cache | |
203 | * - do cache writes asynchronously | |
204 | * - defer writes until cache object lookup completion | |
205 | */ | |
206 | struct fscache_storage { | |
207 | struct fscache_operation op; | |
208 | pgoff_t store_limit; /* don't write more than this */ | |
209 | }; | |
210 | ||
211 | /* | |
212 | * cache operations | |
213 | */ | |
214 | struct fscache_cache_ops { | |
215 | /* name of cache provider */ | |
216 | const char *name; | |
217 | ||
218 | /* allocate an object record for a cookie */ | |
219 | struct fscache_object *(*alloc_object)(struct fscache_cache *cache, | |
220 | struct fscache_cookie *cookie); | |
221 | ||
fee096de DH |
222 | /* look up the object for a cookie |
223 | * - return -ETIMEDOUT to be requeued | |
224 | */ | |
225 | int (*lookup_object)(struct fscache_object *object); | |
0dfc41d1 DH |
226 | |
227 | /* finished looking up */ | |
228 | void (*lookup_complete)(struct fscache_object *object); | |
229 | ||
230 | /* increment the usage count on this object (may fail if unmounting) */ | |
231 | struct fscache_object *(*grab_object)(struct fscache_object *object); | |
232 | ||
233 | /* pin an object in the cache */ | |
234 | int (*pin_object)(struct fscache_object *object); | |
235 | ||
236 | /* unpin an object in the cache */ | |
237 | void (*unpin_object)(struct fscache_object *object); | |
238 | ||
25985edc | 239 | /* store the updated auxiliary data on an object */ |
0dfc41d1 DH |
240 | void (*update_object)(struct fscache_object *object); |
241 | ||
242 | /* discard the resources pinned by an object and effect retirement if | |
243 | * necessary */ | |
244 | void (*drop_object)(struct fscache_object *object); | |
245 | ||
246 | /* dispose of a reference to an object */ | |
247 | void (*put_object)(struct fscache_object *object); | |
248 | ||
249 | /* sync a cache */ | |
250 | void (*sync_cache)(struct fscache_cache *cache); | |
251 | ||
252 | /* notification that the attributes of a non-index object (such as | |
253 | * i_size) have changed */ | |
254 | int (*attr_changed)(struct fscache_object *object); | |
255 | ||
256 | /* reserve space for an object's data and associated metadata */ | |
257 | int (*reserve_space)(struct fscache_object *object, loff_t i_size); | |
258 | ||
259 | /* request a backing block for a page be read or allocated in the | |
260 | * cache */ | |
261 | fscache_page_retrieval_func_t read_or_alloc_page; | |
262 | ||
263 | /* request backing blocks for a list of pages be read or allocated in | |
264 | * the cache */ | |
265 | fscache_pages_retrieval_func_t read_or_alloc_pages; | |
266 | ||
267 | /* request a backing block for a page be allocated in the cache so that | |
268 | * it can be written directly */ | |
269 | fscache_page_retrieval_func_t allocate_page; | |
270 | ||
271 | /* request backing blocks for pages be allocated in the cache so that | |
272 | * they can be written directly */ | |
273 | fscache_pages_retrieval_func_t allocate_pages; | |
274 | ||
275 | /* write a page to its backing block in the cache */ | |
276 | int (*write_page)(struct fscache_storage *op, struct page *page); | |
277 | ||
278 | /* detach backing block from a page (optional) | |
279 | * - must release the cookie lock before returning | |
280 | * - may sleep | |
281 | */ | |
282 | void (*uncache_page)(struct fscache_object *object, | |
283 | struct page *page); | |
284 | ||
285 | /* dissociate a cache from all the pages it was backing */ | |
286 | void (*dissociate_pages)(struct fscache_cache *cache); | |
287 | }; | |
288 | ||
289 | /* | |
290 | * data file or index object cookie | |
291 | * - a file will only appear in one cache | |
292 | * - a request to cache a file may or may not be honoured, subject to | |
293 | * constraints such as disk space | |
294 | * - indices are created on disk just-in-time | |
295 | */ | |
296 | struct fscache_cookie { | |
297 | atomic_t usage; /* number of users of this cookie */ | |
298 | atomic_t n_children; /* number of children of this cookie */ | |
299 | spinlock_t lock; | |
1bccf513 | 300 | spinlock_t stores_lock; /* lock on page store tree */ |
0dfc41d1 DH |
301 | struct hlist_head backing_objects; /* object(s) backing this file/index */ |
302 | const struct fscache_cookie_def *def; /* definition */ | |
303 | struct fscache_cookie *parent; /* parent of this entry */ | |
304 | void *netfs_data; /* back pointer to netfs */ | |
305 | struct radix_tree_root stores; /* pages to be stored on this cookie */ | |
306 | #define FSCACHE_COOKIE_PENDING_TAG 0 /* pages tag: pending write to cache */ | |
201a1542 | 307 | #define FSCACHE_COOKIE_STORING_TAG 1 /* pages tag: writing to cache */ |
0dfc41d1 DH |
308 | |
309 | unsigned long flags; | |
310 | #define FSCACHE_COOKIE_LOOKING_UP 0 /* T if non-index cookie being looked up still */ | |
311 | #define FSCACHE_COOKIE_CREATING 1 /* T if non-index object being created still */ | |
312 | #define FSCACHE_COOKIE_NO_DATA_YET 2 /* T if new object with no cached data yet */ | |
313 | #define FSCACHE_COOKIE_PENDING_FILL 3 /* T if pending initial fill on object */ | |
314 | #define FSCACHE_COOKIE_FILLING 4 /* T if filling object incrementally */ | |
315 | #define FSCACHE_COOKIE_UNAVAILABLE 5 /* T if cookie is unavailable (error, etc) */ | |
316 | }; | |
317 | ||
318 | extern struct fscache_cookie fscache_fsdef_index; | |
319 | ||
320 | /* | |
321 | * on-disk cache file or index handle | |
322 | */ | |
323 | struct fscache_object { | |
324 | enum fscache_object_state { | |
325 | FSCACHE_OBJECT_INIT, /* object in initial unbound state */ | |
326 | FSCACHE_OBJECT_LOOKING_UP, /* looking up object */ | |
327 | FSCACHE_OBJECT_CREATING, /* creating object */ | |
328 | ||
329 | /* active states */ | |
330 | FSCACHE_OBJECT_AVAILABLE, /* cleaning up object after creation */ | |
331 | FSCACHE_OBJECT_ACTIVE, /* object is usable */ | |
332 | FSCACHE_OBJECT_UPDATING, /* object is updating */ | |
333 | ||
334 | /* terminal states */ | |
335 | FSCACHE_OBJECT_DYING, /* object waiting for accessors to finish */ | |
336 | FSCACHE_OBJECT_LC_DYING, /* object cleaning up after lookup/create */ | |
337 | FSCACHE_OBJECT_ABORT_INIT, /* abort the init state */ | |
338 | FSCACHE_OBJECT_RELEASING, /* releasing object */ | |
339 | FSCACHE_OBJECT_RECYCLING, /* retiring object */ | |
340 | FSCACHE_OBJECT_WITHDRAWING, /* withdrawing object */ | |
341 | FSCACHE_OBJECT_DEAD, /* object is now dead */ | |
440f0aff | 342 | FSCACHE_OBJECT__NSTATES |
0dfc41d1 DH |
343 | } state; |
344 | ||
345 | int debug_id; /* debugging ID */ | |
346 | int n_children; /* number of child objects */ | |
347 | int n_ops; /* number of ops outstanding on object */ | |
348 | int n_obj_ops; /* number of object ops outstanding on object */ | |
349 | int n_in_progress; /* number of ops in progress */ | |
350 | int n_exclusive; /* number of exclusive ops queued */ | |
4fbf4291 | 351 | atomic_t n_reads; /* number of read ops in progress */ |
0dfc41d1 DH |
352 | spinlock_t lock; /* state and operations lock */ |
353 | ||
354 | unsigned long lookup_jif; /* time at which lookup started */ | |
355 | unsigned long event_mask; /* events this object is interested in */ | |
356 | unsigned long events; /* events to be processed by this object | |
357 | * (order is important - using fls) */ | |
358 | #define FSCACHE_OBJECT_EV_REQUEUE 0 /* T if object should be requeued */ | |
359 | #define FSCACHE_OBJECT_EV_UPDATE 1 /* T if object should be updated */ | |
360 | #define FSCACHE_OBJECT_EV_CLEARED 2 /* T if accessors all gone */ | |
361 | #define FSCACHE_OBJECT_EV_ERROR 3 /* T if fatal error occurred during processing */ | |
362 | #define FSCACHE_OBJECT_EV_RELEASE 4 /* T if netfs requested object release */ | |
363 | #define FSCACHE_OBJECT_EV_RETIRE 5 /* T if netfs requested object retirement */ | |
364 | #define FSCACHE_OBJECT_EV_WITHDRAW 6 /* T if cache requested object withdrawal */ | |
4fbf4291 | 365 | #define FSCACHE_OBJECT_EVENTS_MASK 0x7f /* mask of all events*/ |
0dfc41d1 DH |
366 | |
367 | unsigned long flags; | |
368 | #define FSCACHE_OBJECT_LOCK 0 /* T if object is busy being processed */ | |
369 | #define FSCACHE_OBJECT_PENDING_WRITE 1 /* T if object has pending write */ | |
370 | #define FSCACHE_OBJECT_WAITING 2 /* T if object is waiting on its parent */ | |
371 | ||
372 | struct list_head cache_link; /* link in cache->object_list */ | |
373 | struct hlist_node cookie_link; /* link in cookie->backing_objects */ | |
374 | struct fscache_cache *cache; /* cache that supplied this object */ | |
375 | struct fscache_cookie *cookie; /* netfs's file/index object */ | |
376 | struct fscache_object *parent; /* parent object */ | |
8b8edefa | 377 | struct work_struct work; /* attention scheduling record */ |
0dfc41d1 DH |
378 | struct list_head dependents; /* FIFO of dependent objects */ |
379 | struct list_head dep_link; /* link in parent's dependents list */ | |
380 | struct list_head pending_ops; /* unstarted operations on this object */ | |
4fbf4291 DH |
381 | #ifdef CONFIG_FSCACHE_OBJECT_LIST |
382 | struct rb_node objlist_link; /* link in global object list */ | |
383 | #endif | |
0dfc41d1 | 384 | pgoff_t store_limit; /* current storage limit */ |
a17754fb | 385 | loff_t store_limit_l; /* current storage limit */ |
0dfc41d1 DH |
386 | }; |
387 | ||
388 | extern const char *fscache_object_states[]; | |
389 | ||
390 | #define fscache_object_is_active(obj) \ | |
391 | (!test_bit(FSCACHE_IOERROR, &(obj)->cache->flags) && \ | |
392 | (obj)->state >= FSCACHE_OBJECT_AVAILABLE && \ | |
393 | (obj)->state < FSCACHE_OBJECT_DYING) | |
394 | ||
60d543ca DH |
395 | #define fscache_object_is_dead(obj) \ |
396 | (test_bit(FSCACHE_IOERROR, &(obj)->cache->flags) && \ | |
397 | (obj)->state >= FSCACHE_OBJECT_DYING) | |
398 | ||
8b8edefa | 399 | extern void fscache_object_work_func(struct work_struct *work); |
0dfc41d1 DH |
400 | |
401 | /** | |
402 | * fscache_object_init - Initialise a cache object description | |
403 | * @object: Object description | |
404 | * | |
405 | * Initialise a cache object description to its basic values. | |
406 | * | |
407 | * See Documentation/filesystems/caching/backend-api.txt for a complete | |
408 | * description. | |
409 | */ | |
410 | static inline | |
411 | void fscache_object_init(struct fscache_object *object, | |
412 | struct fscache_cookie *cookie, | |
413 | struct fscache_cache *cache) | |
414 | { | |
415 | atomic_inc(&cache->object_count); | |
416 | ||
417 | object->state = FSCACHE_OBJECT_INIT; | |
418 | spin_lock_init(&object->lock); | |
419 | INIT_LIST_HEAD(&object->cache_link); | |
420 | INIT_HLIST_NODE(&object->cookie_link); | |
8b8edefa | 421 | INIT_WORK(&object->work, fscache_object_work_func); |
0dfc41d1 DH |
422 | INIT_LIST_HEAD(&object->dependents); |
423 | INIT_LIST_HEAD(&object->dep_link); | |
424 | INIT_LIST_HEAD(&object->pending_ops); | |
425 | object->n_children = 0; | |
426 | object->n_ops = object->n_in_progress = object->n_exclusive = 0; | |
427 | object->events = object->event_mask = 0; | |
428 | object->flags = 0; | |
429 | object->store_limit = 0; | |
a17754fb | 430 | object->store_limit_l = 0; |
0dfc41d1 DH |
431 | object->cache = cache; |
432 | object->cookie = cookie; | |
433 | object->parent = NULL; | |
434 | } | |
435 | ||
436 | extern void fscache_object_lookup_negative(struct fscache_object *object); | |
437 | extern void fscache_obtained_object(struct fscache_object *object); | |
438 | ||
4fbf4291 DH |
439 | #ifdef CONFIG_FSCACHE_OBJECT_LIST |
440 | extern void fscache_object_destroy(struct fscache_object *object); | |
441 | #else | |
442 | #define fscache_object_destroy(object) do {} while(0) | |
443 | #endif | |
444 | ||
0dfc41d1 DH |
445 | /** |
446 | * fscache_object_destroyed - Note destruction of an object in a cache | |
447 | * @cache: The cache from which the object came | |
448 | * | |
449 | * Note the destruction and deallocation of an object record in a cache. | |
450 | */ | |
451 | static inline void fscache_object_destroyed(struct fscache_cache *cache) | |
452 | { | |
453 | if (atomic_dec_and_test(&cache->object_count)) | |
454 | wake_up_all(&fscache_cache_cleared_wq); | |
455 | } | |
456 | ||
457 | /** | |
458 | * fscache_object_lookup_error - Note an object encountered an error | |
459 | * @object: The object on which the error was encountered | |
460 | * | |
461 | * Note that an object encountered a fatal error (usually an I/O error) and | |
462 | * that it should be withdrawn as soon as possible. | |
463 | */ | |
464 | static inline void fscache_object_lookup_error(struct fscache_object *object) | |
465 | { | |
466 | set_bit(FSCACHE_OBJECT_EV_ERROR, &object->events); | |
467 | } | |
468 | ||
469 | /** | |
470 | * fscache_set_store_limit - Set the maximum size to be stored in an object | |
471 | * @object: The object to set the maximum on | |
472 | * @i_size: The limit to set in bytes | |
473 | * | |
474 | * Set the maximum size an object is permitted to reach, implying the highest | |
475 | * byte that may be written. Intended to be called by the attr_changed() op. | |
476 | * | |
477 | * See Documentation/filesystems/caching/backend-api.txt for a complete | |
478 | * description. | |
479 | */ | |
480 | static inline | |
481 | void fscache_set_store_limit(struct fscache_object *object, loff_t i_size) | |
482 | { | |
a17754fb | 483 | object->store_limit_l = i_size; |
0dfc41d1 DH |
484 | object->store_limit = i_size >> PAGE_SHIFT; |
485 | if (i_size & ~PAGE_MASK) | |
486 | object->store_limit++; | |
487 | } | |
488 | ||
489 | /** | |
490 | * fscache_end_io - End a retrieval operation on a page | |
491 | * @op: The FS-Cache operation covering the retrieval | |
492 | * @page: The page that was to be fetched | |
493 | * @error: The error code (0 if successful) | |
494 | * | |
495 | * Note the end of an operation to retrieve a page, as covered by a particular | |
496 | * operation record. | |
497 | */ | |
498 | static inline void fscache_end_io(struct fscache_retrieval *op, | |
499 | struct page *page, int error) | |
500 | { | |
501 | op->end_io_func(page, op->context, error); | |
502 | } | |
503 | ||
504 | /* | |
505 | * out-of-line cache backend functions | |
506 | */ | |
507 | extern void fscache_init_cache(struct fscache_cache *cache, | |
508 | const struct fscache_cache_ops *ops, | |
509 | const char *idfmt, | |
510 | ...) __attribute__ ((format (printf, 3, 4))); | |
511 | ||
512 | extern int fscache_add_cache(struct fscache_cache *cache, | |
513 | struct fscache_object *fsdef, | |
514 | const char *tagname); | |
515 | extern void fscache_withdraw_cache(struct fscache_cache *cache); | |
516 | ||
517 | extern void fscache_io_error(struct fscache_cache *cache); | |
518 | ||
519 | extern void fscache_mark_pages_cached(struct fscache_retrieval *op, | |
520 | struct pagevec *pagevec); | |
521 | ||
8b8edefa TH |
522 | extern bool fscache_object_sleep_till_congested(signed long *timeoutp); |
523 | ||
0dfc41d1 DH |
524 | extern enum fscache_checkaux fscache_check_aux(struct fscache_object *object, |
525 | const void *data, | |
526 | uint16_t datalen); | |
527 | ||
528 | #endif /* _LINUX_FSCACHE_CACHE_H */ |