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b5108822 DH |
1 | /* Cache page management and data I/O routines |
2 | * | |
3 | * Copyright (C) 2004-2008 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 | ||
12 | #define FSCACHE_DEBUG_LEVEL PAGE | |
13 | #include <linux/module.h> | |
14 | #include <linux/fscache-cache.h> | |
15 | #include <linux/buffer_head.h> | |
16 | #include <linux/pagevec.h> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
b5108822 DH |
18 | #include "internal.h" |
19 | ||
20 | /* | |
21 | * check to see if a page is being written to the cache | |
22 | */ | |
23 | bool __fscache_check_page_write(struct fscache_cookie *cookie, struct page *page) | |
24 | { | |
25 | void *val; | |
26 | ||
27 | rcu_read_lock(); | |
28 | val = radix_tree_lookup(&cookie->stores, page->index); | |
29 | rcu_read_unlock(); | |
30 | ||
31 | return val != NULL; | |
32 | } | |
33 | EXPORT_SYMBOL(__fscache_check_page_write); | |
34 | ||
35 | /* | |
36 | * wait for a page to finish being written to the cache | |
37 | */ | |
38 | void __fscache_wait_on_page_write(struct fscache_cookie *cookie, struct page *page) | |
39 | { | |
40 | wait_queue_head_t *wq = bit_waitqueue(&cookie->flags, 0); | |
41 | ||
42 | wait_event(*wq, !__fscache_check_page_write(cookie, page)); | |
43 | } | |
44 | EXPORT_SYMBOL(__fscache_wait_on_page_write); | |
45 | ||
201a1542 DH |
46 | /* |
47 | * decide whether a page can be released, possibly by cancelling a store to it | |
48 | * - we're allowed to sleep if __GFP_WAIT is flagged | |
49 | */ | |
50 | bool __fscache_maybe_release_page(struct fscache_cookie *cookie, | |
51 | struct page *page, | |
52 | gfp_t gfp) | |
53 | { | |
54 | struct page *xpage; | |
55 | void *val; | |
56 | ||
57 | _enter("%p,%p,%x", cookie, page, gfp); | |
58 | ||
8c209ce7 | 59 | try_again: |
201a1542 DH |
60 | rcu_read_lock(); |
61 | val = radix_tree_lookup(&cookie->stores, page->index); | |
62 | if (!val) { | |
63 | rcu_read_unlock(); | |
64 | fscache_stat(&fscache_n_store_vmscan_not_storing); | |
65 | __fscache_uncache_page(cookie, page); | |
66 | return true; | |
67 | } | |
68 | ||
69 | /* see if the page is actually undergoing storage - if so we can't get | |
70 | * rid of it till the cache has finished with it */ | |
71 | if (radix_tree_tag_get(&cookie->stores, page->index, | |
72 | FSCACHE_COOKIE_STORING_TAG)) { | |
73 | rcu_read_unlock(); | |
74 | goto page_busy; | |
75 | } | |
76 | ||
77 | /* the page is pending storage, so we attempt to cancel the store and | |
78 | * discard the store request so that the page can be reclaimed */ | |
79 | spin_lock(&cookie->stores_lock); | |
80 | rcu_read_unlock(); | |
81 | ||
82 | if (radix_tree_tag_get(&cookie->stores, page->index, | |
83 | FSCACHE_COOKIE_STORING_TAG)) { | |
84 | /* the page started to undergo storage whilst we were looking, | |
85 | * so now we can only wait or return */ | |
86 | spin_unlock(&cookie->stores_lock); | |
87 | goto page_busy; | |
88 | } | |
89 | ||
90 | xpage = radix_tree_delete(&cookie->stores, page->index); | |
91 | spin_unlock(&cookie->stores_lock); | |
92 | ||
93 | if (xpage) { | |
94 | fscache_stat(&fscache_n_store_vmscan_cancelled); | |
95 | fscache_stat(&fscache_n_store_radix_deletes); | |
96 | ASSERTCMP(xpage, ==, page); | |
97 | } else { | |
98 | fscache_stat(&fscache_n_store_vmscan_gone); | |
99 | } | |
100 | ||
101 | wake_up_bit(&cookie->flags, 0); | |
102 | if (xpage) | |
103 | page_cache_release(xpage); | |
104 | __fscache_uncache_page(cookie, page); | |
105 | return true; | |
106 | ||
107 | page_busy: | |
8c209ce7 DH |
108 | /* We will wait here if we're allowed to, but that could deadlock the |
109 | * allocator as the work threads writing to the cache may all end up | |
110 | * sleeping on memory allocation, so we may need to impose a timeout | |
111 | * too. */ | |
0c59a95d | 112 | if (!(gfp & __GFP_WAIT) || !(gfp & __GFP_FS)) { |
8c209ce7 DH |
113 | fscache_stat(&fscache_n_store_vmscan_busy); |
114 | return false; | |
115 | } | |
116 | ||
117 | fscache_stat(&fscache_n_store_vmscan_wait); | |
118 | __fscache_wait_on_page_write(cookie, page); | |
119 | gfp &= ~__GFP_WAIT; | |
120 | goto try_again; | |
201a1542 DH |
121 | } |
122 | EXPORT_SYMBOL(__fscache_maybe_release_page); | |
123 | ||
b5108822 DH |
124 | /* |
125 | * note that a page has finished being written to the cache | |
126 | */ | |
1bccf513 DH |
127 | static void fscache_end_page_write(struct fscache_object *object, |
128 | struct page *page) | |
b5108822 | 129 | { |
1bccf513 DH |
130 | struct fscache_cookie *cookie; |
131 | struct page *xpage = NULL; | |
b5108822 | 132 | |
1bccf513 DH |
133 | spin_lock(&object->lock); |
134 | cookie = object->cookie; | |
135 | if (cookie) { | |
136 | /* delete the page from the tree if it is now no longer | |
137 | * pending */ | |
138 | spin_lock(&cookie->stores_lock); | |
201a1542 DH |
139 | radix_tree_tag_clear(&cookie->stores, page->index, |
140 | FSCACHE_COOKIE_STORING_TAG); | |
285e728b DH |
141 | if (!radix_tree_tag_get(&cookie->stores, page->index, |
142 | FSCACHE_COOKIE_PENDING_TAG)) { | |
143 | fscache_stat(&fscache_n_store_radix_deletes); | |
144 | xpage = radix_tree_delete(&cookie->stores, page->index); | |
145 | } | |
1bccf513 DH |
146 | spin_unlock(&cookie->stores_lock); |
147 | wake_up_bit(&cookie->flags, 0); | |
148 | } | |
149 | spin_unlock(&object->lock); | |
150 | if (xpage) | |
151 | page_cache_release(xpage); | |
b5108822 DH |
152 | } |
153 | ||
154 | /* | |
155 | * actually apply the changed attributes to a cache object | |
156 | */ | |
157 | static void fscache_attr_changed_op(struct fscache_operation *op) | |
158 | { | |
159 | struct fscache_object *object = op->object; | |
440f0aff | 160 | int ret; |
b5108822 DH |
161 | |
162 | _enter("{OBJ%x OP%x}", object->debug_id, op->debug_id); | |
163 | ||
164 | fscache_stat(&fscache_n_attr_changed_calls); | |
165 | ||
1362729b DH |
166 | if (fscache_object_is_active(object) && |
167 | fscache_use_cookie(object)) { | |
52bd75fd | 168 | fscache_stat(&fscache_n_cop_attr_changed); |
440f0aff | 169 | ret = object->cache->ops->attr_changed(object); |
52bd75fd | 170 | fscache_stat_d(&fscache_n_cop_attr_changed); |
1362729b | 171 | fscache_unuse_cookie(object); |
440f0aff DH |
172 | if (ret < 0) |
173 | fscache_abort_object(object); | |
174 | } | |
b5108822 | 175 | |
1f372dff | 176 | fscache_op_complete(op, true); |
b5108822 DH |
177 | _leave(""); |
178 | } | |
179 | ||
180 | /* | |
181 | * notification that the attributes on an object have changed | |
182 | */ | |
183 | int __fscache_attr_changed(struct fscache_cookie *cookie) | |
184 | { | |
185 | struct fscache_operation *op; | |
186 | struct fscache_object *object; | |
187 | ||
188 | _enter("%p", cookie); | |
189 | ||
190 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
191 | ||
192 | fscache_stat(&fscache_n_attr_changed); | |
193 | ||
194 | op = kzalloc(sizeof(*op), GFP_KERNEL); | |
195 | if (!op) { | |
196 | fscache_stat(&fscache_n_attr_changed_nomem); | |
197 | _leave(" = -ENOMEM"); | |
198 | return -ENOMEM; | |
199 | } | |
200 | ||
8af7c124 TH |
201 | fscache_operation_init(op, fscache_attr_changed_op, NULL); |
202 | op->flags = FSCACHE_OP_ASYNC | (1 << FSCACHE_OP_EXCLUSIVE); | |
b5108822 DH |
203 | |
204 | spin_lock(&cookie->lock); | |
205 | ||
206 | if (hlist_empty(&cookie->backing_objects)) | |
207 | goto nobufs; | |
208 | object = hlist_entry(cookie->backing_objects.first, | |
209 | struct fscache_object, cookie_link); | |
210 | ||
211 | if (fscache_submit_exclusive_op(object, op) < 0) | |
212 | goto nobufs; | |
213 | spin_unlock(&cookie->lock); | |
214 | fscache_stat(&fscache_n_attr_changed_ok); | |
215 | fscache_put_operation(op); | |
216 | _leave(" = 0"); | |
217 | return 0; | |
218 | ||
219 | nobufs: | |
220 | spin_unlock(&cookie->lock); | |
221 | kfree(op); | |
222 | fscache_stat(&fscache_n_attr_changed_nobufs); | |
223 | _leave(" = %d", -ENOBUFS); | |
224 | return -ENOBUFS; | |
225 | } | |
226 | EXPORT_SYMBOL(__fscache_attr_changed); | |
227 | ||
b5108822 DH |
228 | /* |
229 | * release a retrieval op reference | |
230 | */ | |
231 | static void fscache_release_retrieval_op(struct fscache_operation *_op) | |
232 | { | |
233 | struct fscache_retrieval *op = | |
234 | container_of(_op, struct fscache_retrieval, op); | |
235 | ||
236 | _enter("{OP%x}", op->op.debug_id); | |
237 | ||
1bb4b7f9 | 238 | ASSERTCMP(atomic_read(&op->n_pages), ==, 0); |
9f10523f | 239 | |
b5108822 DH |
240 | fscache_hist(fscache_retrieval_histogram, op->start_time); |
241 | if (op->context) | |
242 | fscache_put_context(op->op.object->cookie, op->context); | |
243 | ||
244 | _leave(""); | |
245 | } | |
246 | ||
247 | /* | |
248 | * allocate a retrieval op | |
249 | */ | |
250 | static struct fscache_retrieval *fscache_alloc_retrieval( | |
1362729b | 251 | struct fscache_cookie *cookie, |
b5108822 DH |
252 | struct address_space *mapping, |
253 | fscache_rw_complete_t end_io_func, | |
254 | void *context) | |
255 | { | |
256 | struct fscache_retrieval *op; | |
257 | ||
258 | /* allocate a retrieval operation and attempt to submit it */ | |
259 | op = kzalloc(sizeof(*op), GFP_NOIO); | |
260 | if (!op) { | |
261 | fscache_stat(&fscache_n_retrievals_nomem); | |
262 | return NULL; | |
263 | } | |
264 | ||
8af7c124 | 265 | fscache_operation_init(&op->op, NULL, fscache_release_retrieval_op); |
1362729b DH |
266 | atomic_inc(&cookie->n_active); |
267 | op->op.flags = FSCACHE_OP_MYTHREAD | | |
268 | (1UL << FSCACHE_OP_WAITING) | | |
269 | (1UL << FSCACHE_OP_UNUSE_COOKIE); | |
b5108822 DH |
270 | op->mapping = mapping; |
271 | op->end_io_func = end_io_func; | |
272 | op->context = context; | |
273 | op->start_time = jiffies; | |
b5108822 DH |
274 | INIT_LIST_HEAD(&op->to_do); |
275 | return op; | |
276 | } | |
277 | ||
278 | /* | |
279 | * wait for a deferred lookup to complete | |
280 | */ | |
da9803bc | 281 | int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie) |
b5108822 DH |
282 | { |
283 | unsigned long jif; | |
284 | ||
285 | _enter(""); | |
286 | ||
287 | if (!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) { | |
288 | _leave(" = 0 [imm]"); | |
289 | return 0; | |
290 | } | |
291 | ||
292 | fscache_stat(&fscache_n_retrievals_wait); | |
293 | ||
294 | jif = jiffies; | |
295 | if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP, | |
296 | fscache_wait_bit_interruptible, | |
297 | TASK_INTERRUPTIBLE) != 0) { | |
298 | fscache_stat(&fscache_n_retrievals_intr); | |
299 | _leave(" = -ERESTARTSYS"); | |
300 | return -ERESTARTSYS; | |
301 | } | |
302 | ||
303 | ASSERT(!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)); | |
304 | ||
305 | smp_rmb(); | |
306 | fscache_hist(fscache_retrieval_delay_histogram, jif); | |
307 | _leave(" = 0 [dly]"); | |
308 | return 0; | |
309 | } | |
310 | ||
91c7fbbf DH |
311 | /* |
312 | * Handle cancellation of a pending retrieval op | |
313 | */ | |
314 | static void fscache_do_cancel_retrieval(struct fscache_operation *_op) | |
315 | { | |
316 | struct fscache_retrieval *op = | |
317 | container_of(_op, struct fscache_retrieval, op); | |
318 | ||
1bb4b7f9 | 319 | atomic_set(&op->n_pages, 0); |
91c7fbbf DH |
320 | } |
321 | ||
60d543ca DH |
322 | /* |
323 | * wait for an object to become active (or dead) | |
324 | */ | |
da9803bc DH |
325 | int fscache_wait_for_operation_activation(struct fscache_object *object, |
326 | struct fscache_operation *op, | |
327 | atomic_t *stat_op_waits, | |
328 | atomic_t *stat_object_dead, | |
329 | void (*do_cancel)(struct fscache_operation *)) | |
60d543ca DH |
330 | { |
331 | int ret; | |
332 | ||
da9803bc | 333 | if (!test_bit(FSCACHE_OP_WAITING, &op->flags)) |
60d543ca DH |
334 | goto check_if_dead; |
335 | ||
336 | _debug(">>> WT"); | |
da9803bc DH |
337 | if (stat_op_waits) |
338 | fscache_stat(stat_op_waits); | |
339 | if (wait_on_bit(&op->flags, FSCACHE_OP_WAITING, | |
60d543ca | 340 | fscache_wait_bit_interruptible, |
9c04caa8 | 341 | TASK_INTERRUPTIBLE) != 0) { |
da9803bc | 342 | ret = fscache_cancel_op(op, do_cancel); |
60d543ca DH |
343 | if (ret == 0) |
344 | return -ERESTARTSYS; | |
345 | ||
346 | /* it's been removed from the pending queue by another party, | |
347 | * so we should get to run shortly */ | |
da9803bc | 348 | wait_on_bit(&op->flags, FSCACHE_OP_WAITING, |
60d543ca DH |
349 | fscache_wait_bit, TASK_UNINTERRUPTIBLE); |
350 | } | |
351 | _debug("<<< GO"); | |
352 | ||
353 | check_if_dead: | |
da9803bc DH |
354 | if (op->state == FSCACHE_OP_ST_CANCELLED) { |
355 | if (stat_object_dead) | |
356 | fscache_stat(stat_object_dead); | |
9f10523f DH |
357 | _leave(" = -ENOBUFS [cancelled]"); |
358 | return -ENOBUFS; | |
359 | } | |
60d543ca | 360 | if (unlikely(fscache_object_is_dead(object))) { |
da9803bc DH |
361 | pr_err("%s() = -ENOBUFS [obj dead %d]\n", __func__, op->state); |
362 | fscache_cancel_op(op, do_cancel); | |
363 | if (stat_object_dead) | |
364 | fscache_stat(stat_object_dead); | |
60d543ca DH |
365 | return -ENOBUFS; |
366 | } | |
367 | return 0; | |
368 | } | |
369 | ||
b5108822 DH |
370 | /* |
371 | * read a page from the cache or allocate a block in which to store it | |
372 | * - we return: | |
373 | * -ENOMEM - out of memory, nothing done | |
374 | * -ERESTARTSYS - interrupted | |
375 | * -ENOBUFS - no backing object available in which to cache the block | |
376 | * -ENODATA - no data available in the backing object for this block | |
377 | * 0 - dispatched a read - it'll call end_io_func() when finished | |
378 | */ | |
379 | int __fscache_read_or_alloc_page(struct fscache_cookie *cookie, | |
380 | struct page *page, | |
381 | fscache_rw_complete_t end_io_func, | |
382 | void *context, | |
383 | gfp_t gfp) | |
384 | { | |
385 | struct fscache_retrieval *op; | |
386 | struct fscache_object *object; | |
387 | int ret; | |
388 | ||
389 | _enter("%p,%p,,,", cookie, page); | |
390 | ||
391 | fscache_stat(&fscache_n_retrievals); | |
392 | ||
393 | if (hlist_empty(&cookie->backing_objects)) | |
394 | goto nobufs; | |
395 | ||
ef778e7a DH |
396 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
397 | _leave(" = -ENOBUFS [invalidating]"); | |
398 | return -ENOBUFS; | |
399 | } | |
400 | ||
b5108822 DH |
401 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); |
402 | ASSERTCMP(page, !=, NULL); | |
403 | ||
404 | if (fscache_wait_for_deferred_lookup(cookie) < 0) | |
405 | return -ERESTARTSYS; | |
406 | ||
1362729b DH |
407 | op = fscache_alloc_retrieval(cookie, page->mapping, |
408 | end_io_func,context); | |
b5108822 DH |
409 | if (!op) { |
410 | _leave(" = -ENOMEM"); | |
411 | return -ENOMEM; | |
412 | } | |
1bb4b7f9 | 413 | atomic_set(&op->n_pages, 1); |
b5108822 DH |
414 | |
415 | spin_lock(&cookie->lock); | |
416 | ||
417 | if (hlist_empty(&cookie->backing_objects)) | |
418 | goto nobufs_unlock; | |
419 | object = hlist_entry(cookie->backing_objects.first, | |
420 | struct fscache_object, cookie_link); | |
421 | ||
caaef690 | 422 | ASSERT(test_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)); |
b5108822 | 423 | |
4fbf4291 | 424 | atomic_inc(&object->n_reads); |
9f10523f | 425 | __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags); |
4fbf4291 | 426 | |
b5108822 | 427 | if (fscache_submit_op(object, &op->op) < 0) |
9f10523f | 428 | goto nobufs_unlock_dec; |
b5108822 DH |
429 | spin_unlock(&cookie->lock); |
430 | ||
431 | fscache_stat(&fscache_n_retrieval_ops); | |
432 | ||
433 | /* pin the netfs read context in case we need to do the actual netfs | |
434 | * read because we've encountered a cache read failure */ | |
435 | fscache_get_context(object->cookie, op->context); | |
436 | ||
437 | /* we wait for the operation to become active, and then process it | |
438 | * *here*, in this thread, and not in the thread pool */ | |
da9803bc DH |
439 | ret = fscache_wait_for_operation_activation( |
440 | object, &op->op, | |
60d543ca | 441 | __fscache_stat(&fscache_n_retrieval_op_waits), |
da9803bc DH |
442 | __fscache_stat(&fscache_n_retrievals_object_dead), |
443 | fscache_do_cancel_retrieval); | |
60d543ca DH |
444 | if (ret < 0) |
445 | goto error; | |
b5108822 DH |
446 | |
447 | /* ask the cache to honour the operation */ | |
448 | if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) { | |
52bd75fd | 449 | fscache_stat(&fscache_n_cop_allocate_page); |
b5108822 | 450 | ret = object->cache->ops->allocate_page(op, page, gfp); |
52bd75fd | 451 | fscache_stat_d(&fscache_n_cop_allocate_page); |
b5108822 DH |
452 | if (ret == 0) |
453 | ret = -ENODATA; | |
454 | } else { | |
52bd75fd | 455 | fscache_stat(&fscache_n_cop_read_or_alloc_page); |
b5108822 | 456 | ret = object->cache->ops->read_or_alloc_page(op, page, gfp); |
52bd75fd | 457 | fscache_stat_d(&fscache_n_cop_read_or_alloc_page); |
b5108822 DH |
458 | } |
459 | ||
5753c441 | 460 | error: |
b5108822 DH |
461 | if (ret == -ENOMEM) |
462 | fscache_stat(&fscache_n_retrievals_nomem); | |
463 | else if (ret == -ERESTARTSYS) | |
464 | fscache_stat(&fscache_n_retrievals_intr); | |
465 | else if (ret == -ENODATA) | |
466 | fscache_stat(&fscache_n_retrievals_nodata); | |
467 | else if (ret < 0) | |
468 | fscache_stat(&fscache_n_retrievals_nobufs); | |
469 | else | |
470 | fscache_stat(&fscache_n_retrievals_ok); | |
471 | ||
472 | fscache_put_retrieval(op); | |
473 | _leave(" = %d", ret); | |
474 | return ret; | |
475 | ||
9f10523f DH |
476 | nobufs_unlock_dec: |
477 | atomic_dec(&object->n_reads); | |
b5108822 DH |
478 | nobufs_unlock: |
479 | spin_unlock(&cookie->lock); | |
1362729b | 480 | atomic_dec(&cookie->n_active); |
b5108822 DH |
481 | kfree(op); |
482 | nobufs: | |
483 | fscache_stat(&fscache_n_retrievals_nobufs); | |
484 | _leave(" = -ENOBUFS"); | |
485 | return -ENOBUFS; | |
486 | } | |
487 | EXPORT_SYMBOL(__fscache_read_or_alloc_page); | |
488 | ||
489 | /* | |
490 | * read a list of page from the cache or allocate a block in which to store | |
491 | * them | |
492 | * - we return: | |
493 | * -ENOMEM - out of memory, some pages may be being read | |
494 | * -ERESTARTSYS - interrupted, some pages may be being read | |
495 | * -ENOBUFS - no backing object or space available in which to cache any | |
496 | * pages not being read | |
497 | * -ENODATA - no data available in the backing object for some or all of | |
498 | * the pages | |
499 | * 0 - dispatched a read on all pages | |
500 | * | |
501 | * end_io_func() will be called for each page read from the cache as it is | |
502 | * finishes being read | |
503 | * | |
504 | * any pages for which a read is dispatched will be removed from pages and | |
505 | * nr_pages | |
506 | */ | |
507 | int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie, | |
508 | struct address_space *mapping, | |
509 | struct list_head *pages, | |
510 | unsigned *nr_pages, | |
511 | fscache_rw_complete_t end_io_func, | |
512 | void *context, | |
513 | gfp_t gfp) | |
514 | { | |
b5108822 DH |
515 | struct fscache_retrieval *op; |
516 | struct fscache_object *object; | |
517 | int ret; | |
518 | ||
519 | _enter("%p,,%d,,,", cookie, *nr_pages); | |
520 | ||
521 | fscache_stat(&fscache_n_retrievals); | |
522 | ||
523 | if (hlist_empty(&cookie->backing_objects)) | |
524 | goto nobufs; | |
525 | ||
ef778e7a DH |
526 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
527 | _leave(" = -ENOBUFS [invalidating]"); | |
528 | return -ENOBUFS; | |
529 | } | |
530 | ||
b5108822 DH |
531 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); |
532 | ASSERTCMP(*nr_pages, >, 0); | |
533 | ASSERT(!list_empty(pages)); | |
534 | ||
535 | if (fscache_wait_for_deferred_lookup(cookie) < 0) | |
536 | return -ERESTARTSYS; | |
537 | ||
1362729b | 538 | op = fscache_alloc_retrieval(cookie, mapping, end_io_func, context); |
b5108822 DH |
539 | if (!op) |
540 | return -ENOMEM; | |
1bb4b7f9 | 541 | atomic_set(&op->n_pages, *nr_pages); |
b5108822 DH |
542 | |
543 | spin_lock(&cookie->lock); | |
544 | ||
545 | if (hlist_empty(&cookie->backing_objects)) | |
546 | goto nobufs_unlock; | |
547 | object = hlist_entry(cookie->backing_objects.first, | |
548 | struct fscache_object, cookie_link); | |
549 | ||
4fbf4291 | 550 | atomic_inc(&object->n_reads); |
9f10523f | 551 | __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags); |
4fbf4291 | 552 | |
b5108822 | 553 | if (fscache_submit_op(object, &op->op) < 0) |
9f10523f | 554 | goto nobufs_unlock_dec; |
b5108822 DH |
555 | spin_unlock(&cookie->lock); |
556 | ||
557 | fscache_stat(&fscache_n_retrieval_ops); | |
558 | ||
559 | /* pin the netfs read context in case we need to do the actual netfs | |
560 | * read because we've encountered a cache read failure */ | |
561 | fscache_get_context(object->cookie, op->context); | |
562 | ||
563 | /* we wait for the operation to become active, and then process it | |
564 | * *here*, in this thread, and not in the thread pool */ | |
da9803bc DH |
565 | ret = fscache_wait_for_operation_activation( |
566 | object, &op->op, | |
60d543ca | 567 | __fscache_stat(&fscache_n_retrieval_op_waits), |
da9803bc DH |
568 | __fscache_stat(&fscache_n_retrievals_object_dead), |
569 | fscache_do_cancel_retrieval); | |
60d543ca DH |
570 | if (ret < 0) |
571 | goto error; | |
b5108822 DH |
572 | |
573 | /* ask the cache to honour the operation */ | |
52bd75fd DH |
574 | if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) { |
575 | fscache_stat(&fscache_n_cop_allocate_pages); | |
576 | ret = object->cache->ops->allocate_pages( | |
577 | op, pages, nr_pages, gfp); | |
578 | fscache_stat_d(&fscache_n_cop_allocate_pages); | |
579 | } else { | |
580 | fscache_stat(&fscache_n_cop_read_or_alloc_pages); | |
581 | ret = object->cache->ops->read_or_alloc_pages( | |
582 | op, pages, nr_pages, gfp); | |
583 | fscache_stat_d(&fscache_n_cop_read_or_alloc_pages); | |
584 | } | |
b5108822 | 585 | |
5753c441 | 586 | error: |
b5108822 DH |
587 | if (ret == -ENOMEM) |
588 | fscache_stat(&fscache_n_retrievals_nomem); | |
589 | else if (ret == -ERESTARTSYS) | |
590 | fscache_stat(&fscache_n_retrievals_intr); | |
591 | else if (ret == -ENODATA) | |
592 | fscache_stat(&fscache_n_retrievals_nodata); | |
593 | else if (ret < 0) | |
594 | fscache_stat(&fscache_n_retrievals_nobufs); | |
595 | else | |
596 | fscache_stat(&fscache_n_retrievals_ok); | |
597 | ||
598 | fscache_put_retrieval(op); | |
599 | _leave(" = %d", ret); | |
600 | return ret; | |
601 | ||
9f10523f DH |
602 | nobufs_unlock_dec: |
603 | atomic_dec(&object->n_reads); | |
b5108822 DH |
604 | nobufs_unlock: |
605 | spin_unlock(&cookie->lock); | |
1362729b | 606 | atomic_dec(&cookie->n_active); |
b5108822 DH |
607 | kfree(op); |
608 | nobufs: | |
609 | fscache_stat(&fscache_n_retrievals_nobufs); | |
610 | _leave(" = -ENOBUFS"); | |
611 | return -ENOBUFS; | |
612 | } | |
613 | EXPORT_SYMBOL(__fscache_read_or_alloc_pages); | |
614 | ||
615 | /* | |
616 | * allocate a block in the cache on which to store a page | |
617 | * - we return: | |
618 | * -ENOMEM - out of memory, nothing done | |
619 | * -ERESTARTSYS - interrupted | |
620 | * -ENOBUFS - no backing object available in which to cache the block | |
621 | * 0 - block allocated | |
622 | */ | |
623 | int __fscache_alloc_page(struct fscache_cookie *cookie, | |
624 | struct page *page, | |
625 | gfp_t gfp) | |
626 | { | |
627 | struct fscache_retrieval *op; | |
628 | struct fscache_object *object; | |
629 | int ret; | |
630 | ||
631 | _enter("%p,%p,,,", cookie, page); | |
632 | ||
633 | fscache_stat(&fscache_n_allocs); | |
634 | ||
635 | if (hlist_empty(&cookie->backing_objects)) | |
636 | goto nobufs; | |
637 | ||
638 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
639 | ASSERTCMP(page, !=, NULL); | |
640 | ||
ef778e7a DH |
641 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
642 | _leave(" = -ENOBUFS [invalidating]"); | |
643 | return -ENOBUFS; | |
644 | } | |
645 | ||
b5108822 DH |
646 | if (fscache_wait_for_deferred_lookup(cookie) < 0) |
647 | return -ERESTARTSYS; | |
648 | ||
1362729b | 649 | op = fscache_alloc_retrieval(cookie, page->mapping, NULL, NULL); |
b5108822 DH |
650 | if (!op) |
651 | return -ENOMEM; | |
1bb4b7f9 | 652 | atomic_set(&op->n_pages, 1); |
b5108822 DH |
653 | |
654 | spin_lock(&cookie->lock); | |
655 | ||
656 | if (hlist_empty(&cookie->backing_objects)) | |
657 | goto nobufs_unlock; | |
658 | object = hlist_entry(cookie->backing_objects.first, | |
659 | struct fscache_object, cookie_link); | |
660 | ||
661 | if (fscache_submit_op(object, &op->op) < 0) | |
662 | goto nobufs_unlock; | |
663 | spin_unlock(&cookie->lock); | |
664 | ||
665 | fscache_stat(&fscache_n_alloc_ops); | |
666 | ||
da9803bc DH |
667 | ret = fscache_wait_for_operation_activation( |
668 | object, &op->op, | |
60d543ca | 669 | __fscache_stat(&fscache_n_alloc_op_waits), |
da9803bc DH |
670 | __fscache_stat(&fscache_n_allocs_object_dead), |
671 | fscache_do_cancel_retrieval); | |
60d543ca DH |
672 | if (ret < 0) |
673 | goto error; | |
b5108822 DH |
674 | |
675 | /* ask the cache to honour the operation */ | |
52bd75fd | 676 | fscache_stat(&fscache_n_cop_allocate_page); |
b5108822 | 677 | ret = object->cache->ops->allocate_page(op, page, gfp); |
52bd75fd | 678 | fscache_stat_d(&fscache_n_cop_allocate_page); |
b5108822 | 679 | |
5753c441 DH |
680 | error: |
681 | if (ret == -ERESTARTSYS) | |
682 | fscache_stat(&fscache_n_allocs_intr); | |
683 | else if (ret < 0) | |
b5108822 DH |
684 | fscache_stat(&fscache_n_allocs_nobufs); |
685 | else | |
686 | fscache_stat(&fscache_n_allocs_ok); | |
687 | ||
688 | fscache_put_retrieval(op); | |
689 | _leave(" = %d", ret); | |
690 | return ret; | |
691 | ||
692 | nobufs_unlock: | |
693 | spin_unlock(&cookie->lock); | |
1362729b | 694 | atomic_dec(&cookie->n_active); |
b5108822 DH |
695 | kfree(op); |
696 | nobufs: | |
697 | fscache_stat(&fscache_n_allocs_nobufs); | |
698 | _leave(" = -ENOBUFS"); | |
699 | return -ENOBUFS; | |
700 | } | |
701 | EXPORT_SYMBOL(__fscache_alloc_page); | |
702 | ||
703 | /* | |
704 | * release a write op reference | |
705 | */ | |
706 | static void fscache_release_write_op(struct fscache_operation *_op) | |
707 | { | |
708 | _enter("{OP%x}", _op->debug_id); | |
709 | } | |
710 | ||
711 | /* | |
712 | * perform the background storage of a page into the cache | |
713 | */ | |
714 | static void fscache_write_op(struct fscache_operation *_op) | |
715 | { | |
716 | struct fscache_storage *op = | |
717 | container_of(_op, struct fscache_storage, op); | |
718 | struct fscache_object *object = op->op.object; | |
1bccf513 | 719 | struct fscache_cookie *cookie; |
b5108822 DH |
720 | struct page *page; |
721 | unsigned n; | |
722 | void *results[1]; | |
723 | int ret; | |
724 | ||
725 | _enter("{OP%x,%d}", op->op.debug_id, atomic_read(&op->op.usage)); | |
726 | ||
b5108822 | 727 | spin_lock(&object->lock); |
1bccf513 | 728 | cookie = object->cookie; |
b5108822 | 729 | |
7ef001e9 DH |
730 | if (!fscache_object_is_active(object)) { |
731 | /* If we get here, then the on-disk cache object likely longer | |
732 | * exists, so we should just cancel this write operation. | |
733 | */ | |
b5108822 | 734 | spin_unlock(&object->lock); |
1f372dff | 735 | fscache_op_complete(&op->op, false); |
7ef001e9 DH |
736 | _leave(" [inactive]"); |
737 | return; | |
738 | } | |
739 | ||
740 | if (!cookie) { | |
741 | /* If we get here, then the cookie belonging to the object was | |
742 | * detached, probably by the cookie being withdrawn due to | |
743 | * memory pressure, which means that the pages we might write | |
744 | * to the cache from no longer exist - therefore, we can just | |
745 | * cancel this write operation. | |
746 | */ | |
747 | spin_unlock(&object->lock); | |
1f372dff | 748 | fscache_op_complete(&op->op, false); |
caaef690 DH |
749 | _leave(" [cancel] op{f=%lx s=%u} obj{s=%s f=%lx}", |
750 | _op->flags, _op->state, object->state->short_name, | |
751 | object->flags); | |
b5108822 DH |
752 | return; |
753 | } | |
754 | ||
1bccf513 DH |
755 | spin_lock(&cookie->stores_lock); |
756 | ||
b5108822 DH |
757 | fscache_stat(&fscache_n_store_calls); |
758 | ||
759 | /* find a page to store */ | |
760 | page = NULL; | |
761 | n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, 1, | |
762 | FSCACHE_COOKIE_PENDING_TAG); | |
763 | if (n != 1) | |
764 | goto superseded; | |
765 | page = results[0]; | |
766 | _debug("gang %d [%lx]", n, page->index); | |
1bccf513 DH |
767 | if (page->index > op->store_limit) { |
768 | fscache_stat(&fscache_n_store_pages_over_limit); | |
b5108822 | 769 | goto superseded; |
1bccf513 | 770 | } |
b5108822 | 771 | |
08a66859 DC |
772 | radix_tree_tag_set(&cookie->stores, page->index, |
773 | FSCACHE_COOKIE_STORING_TAG); | |
774 | radix_tree_tag_clear(&cookie->stores, page->index, | |
775 | FSCACHE_COOKIE_PENDING_TAG); | |
b5108822 | 776 | |
1bccf513 | 777 | spin_unlock(&cookie->stores_lock); |
b5108822 | 778 | spin_unlock(&object->lock); |
b5108822 | 779 | |
08a66859 DC |
780 | fscache_stat(&fscache_n_store_pages); |
781 | fscache_stat(&fscache_n_cop_write_page); | |
782 | ret = object->cache->ops->write_page(op, page); | |
783 | fscache_stat_d(&fscache_n_cop_write_page); | |
08a66859 DC |
784 | fscache_end_page_write(object, page); |
785 | if (ret < 0) { | |
08a66859 | 786 | fscache_abort_object(object); |
1f372dff | 787 | fscache_op_complete(&op->op, true); |
08a66859 DC |
788 | } else { |
789 | fscache_enqueue_operation(&op->op); | |
b5108822 DH |
790 | } |
791 | ||
792 | _leave(""); | |
793 | return; | |
794 | ||
795 | superseded: | |
796 | /* this writer is going away and there aren't any more things to | |
797 | * write */ | |
798 | _debug("cease"); | |
1bccf513 | 799 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
800 | clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags); |
801 | spin_unlock(&object->lock); | |
1f372dff | 802 | fscache_op_complete(&op->op, true); |
b5108822 DH |
803 | _leave(""); |
804 | } | |
805 | ||
ef778e7a DH |
806 | /* |
807 | * Clear the pages pending writing for invalidation | |
808 | */ | |
809 | void fscache_invalidate_writes(struct fscache_cookie *cookie) | |
810 | { | |
811 | struct page *page; | |
812 | void *results[16]; | |
813 | int n, i; | |
814 | ||
815 | _enter(""); | |
816 | ||
ee8be57b SAS |
817 | for (;;) { |
818 | spin_lock(&cookie->stores_lock); | |
819 | n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, | |
820 | ARRAY_SIZE(results), | |
821 | FSCACHE_COOKIE_PENDING_TAG); | |
822 | if (n == 0) { | |
823 | spin_unlock(&cookie->stores_lock); | |
824 | break; | |
825 | } | |
826 | ||
ef778e7a DH |
827 | for (i = n - 1; i >= 0; i--) { |
828 | page = results[i]; | |
829 | radix_tree_delete(&cookie->stores, page->index); | |
830 | } | |
831 | ||
832 | spin_unlock(&cookie->stores_lock); | |
833 | ||
834 | for (i = n - 1; i >= 0; i--) | |
835 | page_cache_release(results[i]); | |
836 | } | |
837 | ||
ef778e7a DH |
838 | _leave(""); |
839 | } | |
840 | ||
b5108822 DH |
841 | /* |
842 | * request a page be stored in the cache | |
843 | * - returns: | |
844 | * -ENOMEM - out of memory, nothing done | |
845 | * -ENOBUFS - no backing object available in which to cache the page | |
846 | * 0 - dispatched a write - it'll call end_io_func() when finished | |
847 | * | |
848 | * if the cookie still has a backing object at this point, that object can be | |
849 | * in one of a few states with respect to storage processing: | |
850 | * | |
851 | * (1) negative lookup, object not yet created (FSCACHE_COOKIE_CREATING is | |
852 | * set) | |
853 | * | |
caaef690 | 854 | * (a) no writes yet |
b5108822 DH |
855 | * |
856 | * (b) writes deferred till post-creation (mark page for writing and | |
857 | * return immediately) | |
858 | * | |
859 | * (2) negative lookup, object created, initial fill being made from netfs | |
b5108822 DH |
860 | * |
861 | * (a) fill point not yet reached this page (mark page for writing and | |
862 | * return) | |
863 | * | |
864 | * (b) fill point passed this page (queue op to store this page) | |
865 | * | |
866 | * (3) object extant (queue op to store this page) | |
867 | * | |
868 | * any other state is invalid | |
869 | */ | |
870 | int __fscache_write_page(struct fscache_cookie *cookie, | |
871 | struct page *page, | |
872 | gfp_t gfp) | |
873 | { | |
874 | struct fscache_storage *op; | |
875 | struct fscache_object *object; | |
876 | int ret; | |
877 | ||
878 | _enter("%p,%x,", cookie, (u32) page->flags); | |
879 | ||
880 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
881 | ASSERT(PageFsCache(page)); | |
882 | ||
883 | fscache_stat(&fscache_n_stores); | |
884 | ||
ef778e7a DH |
885 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
886 | _leave(" = -ENOBUFS [invalidating]"); | |
887 | return -ENOBUFS; | |
888 | } | |
889 | ||
5f4f9f4a | 890 | op = kzalloc(sizeof(*op), GFP_NOIO | __GFP_NOMEMALLOC | __GFP_NORETRY); |
b5108822 DH |
891 | if (!op) |
892 | goto nomem; | |
893 | ||
8af7c124 TH |
894 | fscache_operation_init(&op->op, fscache_write_op, |
895 | fscache_release_write_op); | |
1362729b DH |
896 | op->op.flags = FSCACHE_OP_ASYNC | |
897 | (1 << FSCACHE_OP_WAITING) | | |
898 | (1 << FSCACHE_OP_UNUSE_COOKIE); | |
b5108822 DH |
899 | |
900 | ret = radix_tree_preload(gfp & ~__GFP_HIGHMEM); | |
901 | if (ret < 0) | |
902 | goto nomem_free; | |
903 | ||
904 | ret = -ENOBUFS; | |
905 | spin_lock(&cookie->lock); | |
906 | ||
907 | if (hlist_empty(&cookie->backing_objects)) | |
908 | goto nobufs; | |
909 | object = hlist_entry(cookie->backing_objects.first, | |
910 | struct fscache_object, cookie_link); | |
911 | if (test_bit(FSCACHE_IOERROR, &object->cache->flags)) | |
912 | goto nobufs; | |
913 | ||
914 | /* add the page to the pending-storage radix tree on the backing | |
915 | * object */ | |
916 | spin_lock(&object->lock); | |
1bccf513 | 917 | spin_lock(&cookie->stores_lock); |
b5108822 DH |
918 | |
919 | _debug("store limit %llx", (unsigned long long) object->store_limit); | |
920 | ||
921 | ret = radix_tree_insert(&cookie->stores, page->index, page); | |
922 | if (ret < 0) { | |
923 | if (ret == -EEXIST) | |
924 | goto already_queued; | |
925 | _debug("insert failed %d", ret); | |
926 | goto nobufs_unlock_obj; | |
927 | } | |
928 | ||
929 | radix_tree_tag_set(&cookie->stores, page->index, | |
930 | FSCACHE_COOKIE_PENDING_TAG); | |
931 | page_cache_get(page); | |
932 | ||
933 | /* we only want one writer at a time, but we do need to queue new | |
934 | * writers after exclusive ops */ | |
935 | if (test_and_set_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags)) | |
936 | goto already_pending; | |
937 | ||
1bccf513 | 938 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
939 | spin_unlock(&object->lock); |
940 | ||
941 | op->op.debug_id = atomic_inc_return(&fscache_op_debug_id); | |
942 | op->store_limit = object->store_limit; | |
943 | ||
1362729b | 944 | atomic_inc(&cookie->n_active); |
b5108822 DH |
945 | if (fscache_submit_op(object, &op->op) < 0) |
946 | goto submit_failed; | |
947 | ||
948 | spin_unlock(&cookie->lock); | |
949 | radix_tree_preload_end(); | |
950 | fscache_stat(&fscache_n_store_ops); | |
951 | fscache_stat(&fscache_n_stores_ok); | |
952 | ||
8af7c124 | 953 | /* the work queue now carries its own ref on the object */ |
b5108822 DH |
954 | fscache_put_operation(&op->op); |
955 | _leave(" = 0"); | |
956 | return 0; | |
957 | ||
958 | already_queued: | |
959 | fscache_stat(&fscache_n_stores_again); | |
960 | already_pending: | |
1bccf513 | 961 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
962 | spin_unlock(&object->lock); |
963 | spin_unlock(&cookie->lock); | |
964 | radix_tree_preload_end(); | |
965 | kfree(op); | |
966 | fscache_stat(&fscache_n_stores_ok); | |
967 | _leave(" = 0"); | |
968 | return 0; | |
969 | ||
970 | submit_failed: | |
1362729b | 971 | atomic_dec(&cookie->n_active); |
1bccf513 | 972 | spin_lock(&cookie->stores_lock); |
b5108822 | 973 | radix_tree_delete(&cookie->stores, page->index); |
1bccf513 | 974 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
975 | page_cache_release(page); |
976 | ret = -ENOBUFS; | |
977 | goto nobufs; | |
978 | ||
979 | nobufs_unlock_obj: | |
1147d0f9 | 980 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
981 | spin_unlock(&object->lock); |
982 | nobufs: | |
983 | spin_unlock(&cookie->lock); | |
984 | radix_tree_preload_end(); | |
985 | kfree(op); | |
986 | fscache_stat(&fscache_n_stores_nobufs); | |
987 | _leave(" = -ENOBUFS"); | |
988 | return -ENOBUFS; | |
989 | ||
990 | nomem_free: | |
991 | kfree(op); | |
992 | nomem: | |
993 | fscache_stat(&fscache_n_stores_oom); | |
994 | _leave(" = -ENOMEM"); | |
995 | return -ENOMEM; | |
996 | } | |
997 | EXPORT_SYMBOL(__fscache_write_page); | |
998 | ||
999 | /* | |
1000 | * remove a page from the cache | |
1001 | */ | |
1002 | void __fscache_uncache_page(struct fscache_cookie *cookie, struct page *page) | |
1003 | { | |
1004 | struct fscache_object *object; | |
1005 | ||
1006 | _enter(",%p", page); | |
1007 | ||
1008 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
1009 | ASSERTCMP(page, !=, NULL); | |
1010 | ||
1011 | fscache_stat(&fscache_n_uncaches); | |
1012 | ||
1013 | /* cache withdrawal may beat us to it */ | |
1014 | if (!PageFsCache(page)) | |
1015 | goto done; | |
1016 | ||
1017 | /* get the object */ | |
1018 | spin_lock(&cookie->lock); | |
1019 | ||
1020 | if (hlist_empty(&cookie->backing_objects)) { | |
1021 | ClearPageFsCache(page); | |
1022 | goto done_unlock; | |
1023 | } | |
1024 | ||
1025 | object = hlist_entry(cookie->backing_objects.first, | |
1026 | struct fscache_object, cookie_link); | |
1027 | ||
1028 | /* there might now be stuff on disk we could read */ | |
1029 | clear_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); | |
1030 | ||
1031 | /* only invoke the cache backend if we managed to mark the page | |
1032 | * uncached here; this deals with synchronisation vs withdrawal */ | |
1033 | if (TestClearPageFsCache(page) && | |
1034 | object->cache->ops->uncache_page) { | |
1035 | /* the cache backend releases the cookie lock */ | |
52bd75fd | 1036 | fscache_stat(&fscache_n_cop_uncache_page); |
b5108822 | 1037 | object->cache->ops->uncache_page(object, page); |
52bd75fd | 1038 | fscache_stat_d(&fscache_n_cop_uncache_page); |
b5108822 DH |
1039 | goto done; |
1040 | } | |
1041 | ||
1042 | done_unlock: | |
1043 | spin_unlock(&cookie->lock); | |
1044 | done: | |
1045 | _leave(""); | |
1046 | } | |
1047 | EXPORT_SYMBOL(__fscache_uncache_page); | |
1048 | ||
c4d6d8db DH |
1049 | /** |
1050 | * fscache_mark_page_cached - Mark a page as being cached | |
1051 | * @op: The retrieval op pages are being marked for | |
1052 | * @page: The page to be marked | |
1053 | * | |
1054 | * Mark a netfs page as being cached. After this is called, the netfs | |
1055 | * must call fscache_uncache_page() to remove the mark. | |
1056 | */ | |
1057 | void fscache_mark_page_cached(struct fscache_retrieval *op, struct page *page) | |
1058 | { | |
1059 | struct fscache_cookie *cookie = op->op.object->cookie; | |
1060 | ||
1061 | #ifdef CONFIG_FSCACHE_STATS | |
1062 | atomic_inc(&fscache_n_marks); | |
1063 | #endif | |
1064 | ||
1065 | _debug("- mark %p{%lx}", page, page->index); | |
1066 | if (TestSetPageFsCache(page)) { | |
1067 | static bool once_only; | |
1068 | if (!once_only) { | |
1069 | once_only = true; | |
1070 | printk(KERN_WARNING "FS-Cache:" | |
1071 | " Cookie type %s marked page %lx" | |
1072 | " multiple times\n", | |
1073 | cookie->def->name, page->index); | |
1074 | } | |
1075 | } | |
1076 | ||
1077 | if (cookie->def->mark_page_cached) | |
1078 | cookie->def->mark_page_cached(cookie->netfs_data, | |
1079 | op->mapping, page); | |
1080 | } | |
1081 | EXPORT_SYMBOL(fscache_mark_page_cached); | |
1082 | ||
b5108822 DH |
1083 | /** |
1084 | * fscache_mark_pages_cached - Mark pages as being cached | |
1085 | * @op: The retrieval op pages are being marked for | |
1086 | * @pagevec: The pages to be marked | |
1087 | * | |
1088 | * Mark a bunch of netfs pages as being cached. After this is called, | |
1089 | * the netfs must call fscache_uncache_page() to remove the mark. | |
1090 | */ | |
1091 | void fscache_mark_pages_cached(struct fscache_retrieval *op, | |
1092 | struct pagevec *pagevec) | |
1093 | { | |
b5108822 DH |
1094 | unsigned long loop; |
1095 | ||
c4d6d8db DH |
1096 | for (loop = 0; loop < pagevec->nr; loop++) |
1097 | fscache_mark_page_cached(op, pagevec->pages[loop]); | |
b5108822 | 1098 | |
b5108822 DH |
1099 | pagevec_reinit(pagevec); |
1100 | } | |
1101 | EXPORT_SYMBOL(fscache_mark_pages_cached); | |
c902ce1b DH |
1102 | |
1103 | /* | |
1104 | * Uncache all the pages in an inode that are marked PG_fscache, assuming them | |
1105 | * to be associated with the given cookie. | |
1106 | */ | |
1107 | void __fscache_uncache_all_inode_pages(struct fscache_cookie *cookie, | |
1108 | struct inode *inode) | |
1109 | { | |
1110 | struct address_space *mapping = inode->i_mapping; | |
1111 | struct pagevec pvec; | |
1112 | pgoff_t next; | |
1113 | int i; | |
1114 | ||
1115 | _enter("%p,%p", cookie, inode); | |
1116 | ||
1117 | if (!mapping || mapping->nrpages == 0) { | |
1118 | _leave(" [no pages]"); | |
1119 | return; | |
1120 | } | |
1121 | ||
1122 | pagevec_init(&pvec, 0); | |
1123 | next = 0; | |
b307d465 JB |
1124 | do { |
1125 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) | |
1126 | break; | |
c902ce1b DH |
1127 | for (i = 0; i < pagevec_count(&pvec); i++) { |
1128 | struct page *page = pvec.pages[i]; | |
b307d465 | 1129 | next = page->index; |
c902ce1b DH |
1130 | if (PageFsCache(page)) { |
1131 | __fscache_wait_on_page_write(cookie, page); | |
1132 | __fscache_uncache_page(cookie, page); | |
1133 | } | |
1134 | } | |
1135 | pagevec_release(&pvec); | |
1136 | cond_resched(); | |
b307d465 | 1137 | } while (++next); |
c902ce1b DH |
1138 | |
1139 | _leave(""); | |
1140 | } | |
1141 | EXPORT_SYMBOL(__fscache_uncache_all_inode_pages); |