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Commit | Line | Data |
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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 | ||
8fb883f3 | 166 | if (fscache_object_is_active(object)) { |
52bd75fd | 167 | fscache_stat(&fscache_n_cop_attr_changed); |
440f0aff | 168 | ret = object->cache->ops->attr_changed(object); |
52bd75fd | 169 | fscache_stat_d(&fscache_n_cop_attr_changed); |
440f0aff DH |
170 | if (ret < 0) |
171 | fscache_abort_object(object); | |
172 | } | |
b5108822 | 173 | |
1f372dff | 174 | fscache_op_complete(op, true); |
b5108822 DH |
175 | _leave(""); |
176 | } | |
177 | ||
178 | /* | |
179 | * notification that the attributes on an object have changed | |
180 | */ | |
181 | int __fscache_attr_changed(struct fscache_cookie *cookie) | |
182 | { | |
183 | struct fscache_operation *op; | |
184 | struct fscache_object *object; | |
8fb883f3 | 185 | bool wake_cookie; |
b5108822 DH |
186 | |
187 | _enter("%p", cookie); | |
188 | ||
189 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
190 | ||
191 | fscache_stat(&fscache_n_attr_changed); | |
192 | ||
193 | op = kzalloc(sizeof(*op), GFP_KERNEL); | |
194 | if (!op) { | |
195 | fscache_stat(&fscache_n_attr_changed_nomem); | |
196 | _leave(" = -ENOMEM"); | |
197 | return -ENOMEM; | |
198 | } | |
199 | ||
8af7c124 | 200 | fscache_operation_init(op, fscache_attr_changed_op, NULL); |
8fb883f3 DH |
201 | op->flags = FSCACHE_OP_ASYNC | |
202 | (1 << FSCACHE_OP_EXCLUSIVE) | | |
203 | (1 << FSCACHE_OP_UNUSE_COOKIE); | |
b5108822 DH |
204 | |
205 | spin_lock(&cookie->lock); | |
206 | ||
94d30ae9 DH |
207 | if (!fscache_cookie_enabled(cookie) || |
208 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
209 | goto nobufs; |
210 | object = hlist_entry(cookie->backing_objects.first, | |
211 | struct fscache_object, cookie_link); | |
212 | ||
8fb883f3 | 213 | __fscache_use_cookie(cookie); |
b5108822 DH |
214 | if (fscache_submit_exclusive_op(object, op) < 0) |
215 | goto nobufs; | |
216 | spin_unlock(&cookie->lock); | |
217 | fscache_stat(&fscache_n_attr_changed_ok); | |
218 | fscache_put_operation(op); | |
219 | _leave(" = 0"); | |
220 | return 0; | |
221 | ||
222 | nobufs: | |
8fb883f3 | 223 | wake_cookie = __fscache_unuse_cookie(cookie); |
b5108822 DH |
224 | spin_unlock(&cookie->lock); |
225 | kfree(op); | |
8fb883f3 DH |
226 | if (wake_cookie) |
227 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
228 | fscache_stat(&fscache_n_attr_changed_nobufs); |
229 | _leave(" = %d", -ENOBUFS); | |
230 | return -ENOBUFS; | |
231 | } | |
232 | EXPORT_SYMBOL(__fscache_attr_changed); | |
233 | ||
b5108822 DH |
234 | /* |
235 | * release a retrieval op reference | |
236 | */ | |
237 | static void fscache_release_retrieval_op(struct fscache_operation *_op) | |
238 | { | |
239 | struct fscache_retrieval *op = | |
240 | container_of(_op, struct fscache_retrieval, op); | |
241 | ||
242 | _enter("{OP%x}", op->op.debug_id); | |
243 | ||
1bb4b7f9 | 244 | ASSERTCMP(atomic_read(&op->n_pages), ==, 0); |
9f10523f | 245 | |
b5108822 DH |
246 | fscache_hist(fscache_retrieval_histogram, op->start_time); |
247 | if (op->context) | |
248 | fscache_put_context(op->op.object->cookie, op->context); | |
249 | ||
250 | _leave(""); | |
251 | } | |
252 | ||
253 | /* | |
254 | * allocate a retrieval op | |
255 | */ | |
256 | static struct fscache_retrieval *fscache_alloc_retrieval( | |
1362729b | 257 | struct fscache_cookie *cookie, |
b5108822 DH |
258 | struct address_space *mapping, |
259 | fscache_rw_complete_t end_io_func, | |
260 | void *context) | |
261 | { | |
262 | struct fscache_retrieval *op; | |
263 | ||
264 | /* allocate a retrieval operation and attempt to submit it */ | |
265 | op = kzalloc(sizeof(*op), GFP_NOIO); | |
266 | if (!op) { | |
267 | fscache_stat(&fscache_n_retrievals_nomem); | |
268 | return NULL; | |
269 | } | |
270 | ||
8af7c124 | 271 | fscache_operation_init(&op->op, NULL, fscache_release_retrieval_op); |
1362729b DH |
272 | op->op.flags = FSCACHE_OP_MYTHREAD | |
273 | (1UL << FSCACHE_OP_WAITING) | | |
274 | (1UL << FSCACHE_OP_UNUSE_COOKIE); | |
b5108822 DH |
275 | op->mapping = mapping; |
276 | op->end_io_func = end_io_func; | |
277 | op->context = context; | |
278 | op->start_time = jiffies; | |
b5108822 DH |
279 | INIT_LIST_HEAD(&op->to_do); |
280 | return op; | |
281 | } | |
282 | ||
283 | /* | |
284 | * wait for a deferred lookup to complete | |
285 | */ | |
da9803bc | 286 | int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie) |
b5108822 DH |
287 | { |
288 | unsigned long jif; | |
289 | ||
290 | _enter(""); | |
291 | ||
292 | if (!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) { | |
293 | _leave(" = 0 [imm]"); | |
294 | return 0; | |
295 | } | |
296 | ||
297 | fscache_stat(&fscache_n_retrievals_wait); | |
298 | ||
299 | jif = jiffies; | |
300 | if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP, | |
301 | fscache_wait_bit_interruptible, | |
302 | TASK_INTERRUPTIBLE) != 0) { | |
303 | fscache_stat(&fscache_n_retrievals_intr); | |
304 | _leave(" = -ERESTARTSYS"); | |
305 | return -ERESTARTSYS; | |
306 | } | |
307 | ||
308 | ASSERT(!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)); | |
309 | ||
310 | smp_rmb(); | |
311 | fscache_hist(fscache_retrieval_delay_histogram, jif); | |
312 | _leave(" = 0 [dly]"); | |
313 | return 0; | |
314 | } | |
315 | ||
91c7fbbf DH |
316 | /* |
317 | * Handle cancellation of a pending retrieval op | |
318 | */ | |
319 | static void fscache_do_cancel_retrieval(struct fscache_operation *_op) | |
320 | { | |
321 | struct fscache_retrieval *op = | |
322 | container_of(_op, struct fscache_retrieval, op); | |
323 | ||
1bb4b7f9 | 324 | atomic_set(&op->n_pages, 0); |
91c7fbbf DH |
325 | } |
326 | ||
60d543ca DH |
327 | /* |
328 | * wait for an object to become active (or dead) | |
329 | */ | |
da9803bc DH |
330 | int fscache_wait_for_operation_activation(struct fscache_object *object, |
331 | struct fscache_operation *op, | |
332 | atomic_t *stat_op_waits, | |
333 | atomic_t *stat_object_dead, | |
334 | void (*do_cancel)(struct fscache_operation *)) | |
60d543ca DH |
335 | { |
336 | int ret; | |
337 | ||
da9803bc | 338 | if (!test_bit(FSCACHE_OP_WAITING, &op->flags)) |
60d543ca DH |
339 | goto check_if_dead; |
340 | ||
341 | _debug(">>> WT"); | |
da9803bc DH |
342 | if (stat_op_waits) |
343 | fscache_stat(stat_op_waits); | |
344 | if (wait_on_bit(&op->flags, FSCACHE_OP_WAITING, | |
60d543ca | 345 | fscache_wait_bit_interruptible, |
9c04caa8 | 346 | TASK_INTERRUPTIBLE) != 0) { |
da9803bc | 347 | ret = fscache_cancel_op(op, do_cancel); |
60d543ca DH |
348 | if (ret == 0) |
349 | return -ERESTARTSYS; | |
350 | ||
351 | /* it's been removed from the pending queue by another party, | |
352 | * so we should get to run shortly */ | |
da9803bc | 353 | wait_on_bit(&op->flags, FSCACHE_OP_WAITING, |
60d543ca DH |
354 | fscache_wait_bit, TASK_UNINTERRUPTIBLE); |
355 | } | |
356 | _debug("<<< GO"); | |
357 | ||
358 | check_if_dead: | |
da9803bc DH |
359 | if (op->state == FSCACHE_OP_ST_CANCELLED) { |
360 | if (stat_object_dead) | |
361 | fscache_stat(stat_object_dead); | |
9f10523f DH |
362 | _leave(" = -ENOBUFS [cancelled]"); |
363 | return -ENOBUFS; | |
364 | } | |
60d543ca | 365 | if (unlikely(fscache_object_is_dead(object))) { |
da9803bc DH |
366 | pr_err("%s() = -ENOBUFS [obj dead %d]\n", __func__, op->state); |
367 | fscache_cancel_op(op, do_cancel); | |
368 | if (stat_object_dead) | |
369 | fscache_stat(stat_object_dead); | |
60d543ca DH |
370 | return -ENOBUFS; |
371 | } | |
372 | return 0; | |
373 | } | |
374 | ||
b5108822 DH |
375 | /* |
376 | * read a page from the cache or allocate a block in which to store it | |
377 | * - we return: | |
378 | * -ENOMEM - out of memory, nothing done | |
379 | * -ERESTARTSYS - interrupted | |
380 | * -ENOBUFS - no backing object available in which to cache the block | |
381 | * -ENODATA - no data available in the backing object for this block | |
382 | * 0 - dispatched a read - it'll call end_io_func() when finished | |
383 | */ | |
384 | int __fscache_read_or_alloc_page(struct fscache_cookie *cookie, | |
385 | struct page *page, | |
386 | fscache_rw_complete_t end_io_func, | |
387 | void *context, | |
388 | gfp_t gfp) | |
389 | { | |
390 | struct fscache_retrieval *op; | |
391 | struct fscache_object *object; | |
8fb883f3 | 392 | bool wake_cookie = false; |
b5108822 DH |
393 | int ret; |
394 | ||
395 | _enter("%p,%p,,,", cookie, page); | |
396 | ||
397 | fscache_stat(&fscache_n_retrievals); | |
398 | ||
399 | if (hlist_empty(&cookie->backing_objects)) | |
400 | goto nobufs; | |
401 | ||
ef778e7a DH |
402 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
403 | _leave(" = -ENOBUFS [invalidating]"); | |
404 | return -ENOBUFS; | |
405 | } | |
406 | ||
b5108822 DH |
407 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); |
408 | ASSERTCMP(page, !=, NULL); | |
409 | ||
410 | if (fscache_wait_for_deferred_lookup(cookie) < 0) | |
411 | return -ERESTARTSYS; | |
412 | ||
1362729b | 413 | op = fscache_alloc_retrieval(cookie, page->mapping, |
94d30ae9 | 414 | end_io_func, context); |
b5108822 DH |
415 | if (!op) { |
416 | _leave(" = -ENOMEM"); | |
417 | return -ENOMEM; | |
418 | } | |
1bb4b7f9 | 419 | atomic_set(&op->n_pages, 1); |
b5108822 DH |
420 | |
421 | spin_lock(&cookie->lock); | |
422 | ||
94d30ae9 DH |
423 | if (!fscache_cookie_enabled(cookie) || |
424 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
425 | goto nobufs_unlock; |
426 | object = hlist_entry(cookie->backing_objects.first, | |
427 | struct fscache_object, cookie_link); | |
428 | ||
caaef690 | 429 | ASSERT(test_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)); |
b5108822 | 430 | |
8fb883f3 | 431 | __fscache_use_cookie(cookie); |
4fbf4291 | 432 | atomic_inc(&object->n_reads); |
9f10523f | 433 | __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags); |
4fbf4291 | 434 | |
b5108822 | 435 | if (fscache_submit_op(object, &op->op) < 0) |
9f10523f | 436 | goto nobufs_unlock_dec; |
b5108822 DH |
437 | spin_unlock(&cookie->lock); |
438 | ||
439 | fscache_stat(&fscache_n_retrieval_ops); | |
440 | ||
441 | /* pin the netfs read context in case we need to do the actual netfs | |
442 | * read because we've encountered a cache read failure */ | |
443 | fscache_get_context(object->cookie, op->context); | |
444 | ||
445 | /* we wait for the operation to become active, and then process it | |
446 | * *here*, in this thread, and not in the thread pool */ | |
da9803bc DH |
447 | ret = fscache_wait_for_operation_activation( |
448 | object, &op->op, | |
60d543ca | 449 | __fscache_stat(&fscache_n_retrieval_op_waits), |
da9803bc DH |
450 | __fscache_stat(&fscache_n_retrievals_object_dead), |
451 | fscache_do_cancel_retrieval); | |
60d543ca DH |
452 | if (ret < 0) |
453 | goto error; | |
b5108822 DH |
454 | |
455 | /* ask the cache to honour the operation */ | |
456 | if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) { | |
52bd75fd | 457 | fscache_stat(&fscache_n_cop_allocate_page); |
b5108822 | 458 | ret = object->cache->ops->allocate_page(op, page, gfp); |
52bd75fd | 459 | fscache_stat_d(&fscache_n_cop_allocate_page); |
b5108822 DH |
460 | if (ret == 0) |
461 | ret = -ENODATA; | |
462 | } else { | |
52bd75fd | 463 | fscache_stat(&fscache_n_cop_read_or_alloc_page); |
b5108822 | 464 | ret = object->cache->ops->read_or_alloc_page(op, page, gfp); |
52bd75fd | 465 | fscache_stat_d(&fscache_n_cop_read_or_alloc_page); |
b5108822 DH |
466 | } |
467 | ||
5753c441 | 468 | error: |
b5108822 DH |
469 | if (ret == -ENOMEM) |
470 | fscache_stat(&fscache_n_retrievals_nomem); | |
471 | else if (ret == -ERESTARTSYS) | |
472 | fscache_stat(&fscache_n_retrievals_intr); | |
473 | else if (ret == -ENODATA) | |
474 | fscache_stat(&fscache_n_retrievals_nodata); | |
475 | else if (ret < 0) | |
476 | fscache_stat(&fscache_n_retrievals_nobufs); | |
477 | else | |
478 | fscache_stat(&fscache_n_retrievals_ok); | |
479 | ||
480 | fscache_put_retrieval(op); | |
481 | _leave(" = %d", ret); | |
482 | return ret; | |
483 | ||
9f10523f DH |
484 | nobufs_unlock_dec: |
485 | atomic_dec(&object->n_reads); | |
8fb883f3 | 486 | wake_cookie = __fscache_unuse_cookie(cookie); |
b5108822 DH |
487 | nobufs_unlock: |
488 | spin_unlock(&cookie->lock); | |
8fb883f3 DH |
489 | if (wake_cookie) |
490 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
491 | kfree(op); |
492 | nobufs: | |
493 | fscache_stat(&fscache_n_retrievals_nobufs); | |
494 | _leave(" = -ENOBUFS"); | |
495 | return -ENOBUFS; | |
496 | } | |
497 | EXPORT_SYMBOL(__fscache_read_or_alloc_page); | |
498 | ||
499 | /* | |
500 | * read a list of page from the cache or allocate a block in which to store | |
501 | * them | |
502 | * - we return: | |
503 | * -ENOMEM - out of memory, some pages may be being read | |
504 | * -ERESTARTSYS - interrupted, some pages may be being read | |
505 | * -ENOBUFS - no backing object or space available in which to cache any | |
506 | * pages not being read | |
507 | * -ENODATA - no data available in the backing object for some or all of | |
508 | * the pages | |
509 | * 0 - dispatched a read on all pages | |
510 | * | |
511 | * end_io_func() will be called for each page read from the cache as it is | |
512 | * finishes being read | |
513 | * | |
514 | * any pages for which a read is dispatched will be removed from pages and | |
515 | * nr_pages | |
516 | */ | |
517 | int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie, | |
518 | struct address_space *mapping, | |
519 | struct list_head *pages, | |
520 | unsigned *nr_pages, | |
521 | fscache_rw_complete_t end_io_func, | |
522 | void *context, | |
523 | gfp_t gfp) | |
524 | { | |
b5108822 DH |
525 | struct fscache_retrieval *op; |
526 | struct fscache_object *object; | |
8fb883f3 | 527 | bool wake_cookie = false; |
b5108822 DH |
528 | int ret; |
529 | ||
530 | _enter("%p,,%d,,,", cookie, *nr_pages); | |
531 | ||
532 | fscache_stat(&fscache_n_retrievals); | |
533 | ||
534 | if (hlist_empty(&cookie->backing_objects)) | |
535 | goto nobufs; | |
536 | ||
ef778e7a DH |
537 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
538 | _leave(" = -ENOBUFS [invalidating]"); | |
539 | return -ENOBUFS; | |
540 | } | |
541 | ||
b5108822 DH |
542 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); |
543 | ASSERTCMP(*nr_pages, >, 0); | |
544 | ASSERT(!list_empty(pages)); | |
545 | ||
546 | if (fscache_wait_for_deferred_lookup(cookie) < 0) | |
547 | return -ERESTARTSYS; | |
548 | ||
1362729b | 549 | op = fscache_alloc_retrieval(cookie, mapping, end_io_func, context); |
b5108822 DH |
550 | if (!op) |
551 | return -ENOMEM; | |
1bb4b7f9 | 552 | atomic_set(&op->n_pages, *nr_pages); |
b5108822 DH |
553 | |
554 | spin_lock(&cookie->lock); | |
555 | ||
94d30ae9 DH |
556 | if (!fscache_cookie_enabled(cookie) || |
557 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
558 | goto nobufs_unlock; |
559 | object = hlist_entry(cookie->backing_objects.first, | |
560 | struct fscache_object, cookie_link); | |
561 | ||
8fb883f3 | 562 | __fscache_use_cookie(cookie); |
4fbf4291 | 563 | atomic_inc(&object->n_reads); |
9f10523f | 564 | __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags); |
4fbf4291 | 565 | |
b5108822 | 566 | if (fscache_submit_op(object, &op->op) < 0) |
9f10523f | 567 | goto nobufs_unlock_dec; |
b5108822 DH |
568 | spin_unlock(&cookie->lock); |
569 | ||
570 | fscache_stat(&fscache_n_retrieval_ops); | |
571 | ||
572 | /* pin the netfs read context in case we need to do the actual netfs | |
573 | * read because we've encountered a cache read failure */ | |
574 | fscache_get_context(object->cookie, op->context); | |
575 | ||
576 | /* we wait for the operation to become active, and then process it | |
577 | * *here*, in this thread, and not in the thread pool */ | |
da9803bc DH |
578 | ret = fscache_wait_for_operation_activation( |
579 | object, &op->op, | |
60d543ca | 580 | __fscache_stat(&fscache_n_retrieval_op_waits), |
da9803bc DH |
581 | __fscache_stat(&fscache_n_retrievals_object_dead), |
582 | fscache_do_cancel_retrieval); | |
60d543ca DH |
583 | if (ret < 0) |
584 | goto error; | |
b5108822 DH |
585 | |
586 | /* ask the cache to honour the operation */ | |
52bd75fd DH |
587 | if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) { |
588 | fscache_stat(&fscache_n_cop_allocate_pages); | |
589 | ret = object->cache->ops->allocate_pages( | |
590 | op, pages, nr_pages, gfp); | |
591 | fscache_stat_d(&fscache_n_cop_allocate_pages); | |
592 | } else { | |
593 | fscache_stat(&fscache_n_cop_read_or_alloc_pages); | |
594 | ret = object->cache->ops->read_or_alloc_pages( | |
595 | op, pages, nr_pages, gfp); | |
596 | fscache_stat_d(&fscache_n_cop_read_or_alloc_pages); | |
597 | } | |
b5108822 | 598 | |
5753c441 | 599 | error: |
b5108822 DH |
600 | if (ret == -ENOMEM) |
601 | fscache_stat(&fscache_n_retrievals_nomem); | |
602 | else if (ret == -ERESTARTSYS) | |
603 | fscache_stat(&fscache_n_retrievals_intr); | |
604 | else if (ret == -ENODATA) | |
605 | fscache_stat(&fscache_n_retrievals_nodata); | |
606 | else if (ret < 0) | |
607 | fscache_stat(&fscache_n_retrievals_nobufs); | |
608 | else | |
609 | fscache_stat(&fscache_n_retrievals_ok); | |
610 | ||
611 | fscache_put_retrieval(op); | |
612 | _leave(" = %d", ret); | |
613 | return ret; | |
614 | ||
9f10523f DH |
615 | nobufs_unlock_dec: |
616 | atomic_dec(&object->n_reads); | |
8fb883f3 | 617 | wake_cookie = __fscache_unuse_cookie(cookie); |
b5108822 DH |
618 | nobufs_unlock: |
619 | spin_unlock(&cookie->lock); | |
620 | kfree(op); | |
8fb883f3 DH |
621 | if (wake_cookie) |
622 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
623 | nobufs: |
624 | fscache_stat(&fscache_n_retrievals_nobufs); | |
625 | _leave(" = -ENOBUFS"); | |
626 | return -ENOBUFS; | |
627 | } | |
628 | EXPORT_SYMBOL(__fscache_read_or_alloc_pages); | |
629 | ||
630 | /* | |
631 | * allocate a block in the cache on which to store a page | |
632 | * - we return: | |
633 | * -ENOMEM - out of memory, nothing done | |
634 | * -ERESTARTSYS - interrupted | |
635 | * -ENOBUFS - no backing object available in which to cache the block | |
636 | * 0 - block allocated | |
637 | */ | |
638 | int __fscache_alloc_page(struct fscache_cookie *cookie, | |
639 | struct page *page, | |
640 | gfp_t gfp) | |
641 | { | |
642 | struct fscache_retrieval *op; | |
643 | struct fscache_object *object; | |
8fb883f3 | 644 | bool wake_cookie = false; |
b5108822 DH |
645 | int ret; |
646 | ||
647 | _enter("%p,%p,,,", cookie, page); | |
648 | ||
649 | fscache_stat(&fscache_n_allocs); | |
650 | ||
651 | if (hlist_empty(&cookie->backing_objects)) | |
652 | goto nobufs; | |
653 | ||
654 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
655 | ASSERTCMP(page, !=, NULL); | |
656 | ||
ef778e7a DH |
657 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
658 | _leave(" = -ENOBUFS [invalidating]"); | |
659 | return -ENOBUFS; | |
660 | } | |
661 | ||
b5108822 DH |
662 | if (fscache_wait_for_deferred_lookup(cookie) < 0) |
663 | return -ERESTARTSYS; | |
664 | ||
1362729b | 665 | op = fscache_alloc_retrieval(cookie, page->mapping, NULL, NULL); |
b5108822 DH |
666 | if (!op) |
667 | return -ENOMEM; | |
1bb4b7f9 | 668 | atomic_set(&op->n_pages, 1); |
b5108822 DH |
669 | |
670 | spin_lock(&cookie->lock); | |
671 | ||
94d30ae9 DH |
672 | if (!fscache_cookie_enabled(cookie) || |
673 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
674 | goto nobufs_unlock; |
675 | object = hlist_entry(cookie->backing_objects.first, | |
676 | struct fscache_object, cookie_link); | |
677 | ||
8fb883f3 | 678 | __fscache_use_cookie(cookie); |
b5108822 | 679 | if (fscache_submit_op(object, &op->op) < 0) |
8fb883f3 | 680 | goto nobufs_unlock_dec; |
b5108822 DH |
681 | spin_unlock(&cookie->lock); |
682 | ||
683 | fscache_stat(&fscache_n_alloc_ops); | |
684 | ||
da9803bc DH |
685 | ret = fscache_wait_for_operation_activation( |
686 | object, &op->op, | |
60d543ca | 687 | __fscache_stat(&fscache_n_alloc_op_waits), |
da9803bc DH |
688 | __fscache_stat(&fscache_n_allocs_object_dead), |
689 | fscache_do_cancel_retrieval); | |
60d543ca DH |
690 | if (ret < 0) |
691 | goto error; | |
b5108822 DH |
692 | |
693 | /* ask the cache to honour the operation */ | |
52bd75fd | 694 | fscache_stat(&fscache_n_cop_allocate_page); |
b5108822 | 695 | ret = object->cache->ops->allocate_page(op, page, gfp); |
52bd75fd | 696 | fscache_stat_d(&fscache_n_cop_allocate_page); |
b5108822 | 697 | |
5753c441 DH |
698 | error: |
699 | if (ret == -ERESTARTSYS) | |
700 | fscache_stat(&fscache_n_allocs_intr); | |
701 | else if (ret < 0) | |
b5108822 DH |
702 | fscache_stat(&fscache_n_allocs_nobufs); |
703 | else | |
704 | fscache_stat(&fscache_n_allocs_ok); | |
705 | ||
706 | fscache_put_retrieval(op); | |
707 | _leave(" = %d", ret); | |
708 | return ret; | |
709 | ||
8fb883f3 DH |
710 | nobufs_unlock_dec: |
711 | wake_cookie = __fscache_unuse_cookie(cookie); | |
b5108822 DH |
712 | nobufs_unlock: |
713 | spin_unlock(&cookie->lock); | |
714 | kfree(op); | |
8fb883f3 DH |
715 | if (wake_cookie) |
716 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
717 | nobufs: |
718 | fscache_stat(&fscache_n_allocs_nobufs); | |
719 | _leave(" = -ENOBUFS"); | |
720 | return -ENOBUFS; | |
721 | } | |
722 | EXPORT_SYMBOL(__fscache_alloc_page); | |
723 | ||
5a6f282a MT |
724 | /* |
725 | * Unmark pages allocate in the readahead code path (via: | |
726 | * fscache_readpages_or_alloc) after delegating to the base filesystem | |
727 | */ | |
728 | void __fscache_readpages_cancel(struct fscache_cookie *cookie, | |
729 | struct list_head *pages) | |
730 | { | |
731 | struct page *page; | |
732 | ||
733 | list_for_each_entry(page, pages, lru) { | |
734 | if (PageFsCache(page)) | |
735 | __fscache_uncache_page(cookie, page); | |
736 | } | |
737 | } | |
738 | EXPORT_SYMBOL(__fscache_readpages_cancel); | |
739 | ||
b5108822 DH |
740 | /* |
741 | * release a write op reference | |
742 | */ | |
743 | static void fscache_release_write_op(struct fscache_operation *_op) | |
744 | { | |
745 | _enter("{OP%x}", _op->debug_id); | |
746 | } | |
747 | ||
748 | /* | |
749 | * perform the background storage of a page into the cache | |
750 | */ | |
751 | static void fscache_write_op(struct fscache_operation *_op) | |
752 | { | |
753 | struct fscache_storage *op = | |
754 | container_of(_op, struct fscache_storage, op); | |
755 | struct fscache_object *object = op->op.object; | |
1bccf513 | 756 | struct fscache_cookie *cookie; |
b5108822 DH |
757 | struct page *page; |
758 | unsigned n; | |
759 | void *results[1]; | |
760 | int ret; | |
761 | ||
762 | _enter("{OP%x,%d}", op->op.debug_id, atomic_read(&op->op.usage)); | |
763 | ||
b5108822 | 764 | spin_lock(&object->lock); |
1bccf513 | 765 | cookie = object->cookie; |
b5108822 | 766 | |
7ef001e9 DH |
767 | if (!fscache_object_is_active(object)) { |
768 | /* If we get here, then the on-disk cache object likely longer | |
769 | * exists, so we should just cancel this write operation. | |
770 | */ | |
b5108822 | 771 | spin_unlock(&object->lock); |
1f372dff | 772 | fscache_op_complete(&op->op, false); |
7ef001e9 DH |
773 | _leave(" [inactive]"); |
774 | return; | |
775 | } | |
776 | ||
777 | if (!cookie) { | |
778 | /* If we get here, then the cookie belonging to the object was | |
779 | * detached, probably by the cookie being withdrawn due to | |
780 | * memory pressure, which means that the pages we might write | |
781 | * to the cache from no longer exist - therefore, we can just | |
782 | * cancel this write operation. | |
783 | */ | |
784 | spin_unlock(&object->lock); | |
1f372dff | 785 | fscache_op_complete(&op->op, false); |
caaef690 DH |
786 | _leave(" [cancel] op{f=%lx s=%u} obj{s=%s f=%lx}", |
787 | _op->flags, _op->state, object->state->short_name, | |
788 | object->flags); | |
b5108822 DH |
789 | return; |
790 | } | |
791 | ||
1bccf513 DH |
792 | spin_lock(&cookie->stores_lock); |
793 | ||
b5108822 DH |
794 | fscache_stat(&fscache_n_store_calls); |
795 | ||
796 | /* find a page to store */ | |
797 | page = NULL; | |
798 | n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, 1, | |
799 | FSCACHE_COOKIE_PENDING_TAG); | |
800 | if (n != 1) | |
801 | goto superseded; | |
802 | page = results[0]; | |
803 | _debug("gang %d [%lx]", n, page->index); | |
1bccf513 DH |
804 | if (page->index > op->store_limit) { |
805 | fscache_stat(&fscache_n_store_pages_over_limit); | |
b5108822 | 806 | goto superseded; |
1bccf513 | 807 | } |
b5108822 | 808 | |
08a66859 DC |
809 | radix_tree_tag_set(&cookie->stores, page->index, |
810 | FSCACHE_COOKIE_STORING_TAG); | |
811 | radix_tree_tag_clear(&cookie->stores, page->index, | |
812 | FSCACHE_COOKIE_PENDING_TAG); | |
b5108822 | 813 | |
1bccf513 | 814 | spin_unlock(&cookie->stores_lock); |
b5108822 | 815 | spin_unlock(&object->lock); |
b5108822 | 816 | |
08a66859 DC |
817 | fscache_stat(&fscache_n_store_pages); |
818 | fscache_stat(&fscache_n_cop_write_page); | |
819 | ret = object->cache->ops->write_page(op, page); | |
820 | fscache_stat_d(&fscache_n_cop_write_page); | |
08a66859 DC |
821 | fscache_end_page_write(object, page); |
822 | if (ret < 0) { | |
08a66859 | 823 | fscache_abort_object(object); |
1f372dff | 824 | fscache_op_complete(&op->op, true); |
08a66859 DC |
825 | } else { |
826 | fscache_enqueue_operation(&op->op); | |
b5108822 DH |
827 | } |
828 | ||
829 | _leave(""); | |
830 | return; | |
831 | ||
832 | superseded: | |
833 | /* this writer is going away and there aren't any more things to | |
834 | * write */ | |
835 | _debug("cease"); | |
1bccf513 | 836 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
837 | clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags); |
838 | spin_unlock(&object->lock); | |
1f372dff | 839 | fscache_op_complete(&op->op, true); |
b5108822 DH |
840 | _leave(""); |
841 | } | |
842 | ||
ef778e7a DH |
843 | /* |
844 | * Clear the pages pending writing for invalidation | |
845 | */ | |
846 | void fscache_invalidate_writes(struct fscache_cookie *cookie) | |
847 | { | |
848 | struct page *page; | |
849 | void *results[16]; | |
850 | int n, i; | |
851 | ||
852 | _enter(""); | |
853 | ||
ee8be57b SAS |
854 | for (;;) { |
855 | spin_lock(&cookie->stores_lock); | |
856 | n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, | |
857 | ARRAY_SIZE(results), | |
858 | FSCACHE_COOKIE_PENDING_TAG); | |
859 | if (n == 0) { | |
860 | spin_unlock(&cookie->stores_lock); | |
861 | break; | |
862 | } | |
863 | ||
ef778e7a DH |
864 | for (i = n - 1; i >= 0; i--) { |
865 | page = results[i]; | |
866 | radix_tree_delete(&cookie->stores, page->index); | |
867 | } | |
868 | ||
869 | spin_unlock(&cookie->stores_lock); | |
870 | ||
871 | for (i = n - 1; i >= 0; i--) | |
872 | page_cache_release(results[i]); | |
873 | } | |
874 | ||
ef778e7a DH |
875 | _leave(""); |
876 | } | |
877 | ||
b5108822 DH |
878 | /* |
879 | * request a page be stored in the cache | |
880 | * - returns: | |
881 | * -ENOMEM - out of memory, nothing done | |
882 | * -ENOBUFS - no backing object available in which to cache the page | |
883 | * 0 - dispatched a write - it'll call end_io_func() when finished | |
884 | * | |
885 | * if the cookie still has a backing object at this point, that object can be | |
886 | * in one of a few states with respect to storage processing: | |
887 | * | |
888 | * (1) negative lookup, object not yet created (FSCACHE_COOKIE_CREATING is | |
889 | * set) | |
890 | * | |
caaef690 | 891 | * (a) no writes yet |
b5108822 DH |
892 | * |
893 | * (b) writes deferred till post-creation (mark page for writing and | |
894 | * return immediately) | |
895 | * | |
896 | * (2) negative lookup, object created, initial fill being made from netfs | |
b5108822 DH |
897 | * |
898 | * (a) fill point not yet reached this page (mark page for writing and | |
899 | * return) | |
900 | * | |
901 | * (b) fill point passed this page (queue op to store this page) | |
902 | * | |
903 | * (3) object extant (queue op to store this page) | |
904 | * | |
905 | * any other state is invalid | |
906 | */ | |
907 | int __fscache_write_page(struct fscache_cookie *cookie, | |
908 | struct page *page, | |
909 | gfp_t gfp) | |
910 | { | |
911 | struct fscache_storage *op; | |
912 | struct fscache_object *object; | |
8fb883f3 | 913 | bool wake_cookie = false; |
b5108822 DH |
914 | int ret; |
915 | ||
916 | _enter("%p,%x,", cookie, (u32) page->flags); | |
917 | ||
918 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
919 | ASSERT(PageFsCache(page)); | |
920 | ||
921 | fscache_stat(&fscache_n_stores); | |
922 | ||
ef778e7a DH |
923 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
924 | _leave(" = -ENOBUFS [invalidating]"); | |
925 | return -ENOBUFS; | |
926 | } | |
927 | ||
5f4f9f4a | 928 | op = kzalloc(sizeof(*op), GFP_NOIO | __GFP_NOMEMALLOC | __GFP_NORETRY); |
b5108822 DH |
929 | if (!op) |
930 | goto nomem; | |
931 | ||
8af7c124 TH |
932 | fscache_operation_init(&op->op, fscache_write_op, |
933 | fscache_release_write_op); | |
1362729b DH |
934 | op->op.flags = FSCACHE_OP_ASYNC | |
935 | (1 << FSCACHE_OP_WAITING) | | |
936 | (1 << FSCACHE_OP_UNUSE_COOKIE); | |
b5108822 | 937 | |
5e4c0d97 | 938 | ret = radix_tree_maybe_preload(gfp & ~__GFP_HIGHMEM); |
b5108822 DH |
939 | if (ret < 0) |
940 | goto nomem_free; | |
941 | ||
942 | ret = -ENOBUFS; | |
943 | spin_lock(&cookie->lock); | |
944 | ||
94d30ae9 DH |
945 | if (!fscache_cookie_enabled(cookie) || |
946 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
947 | goto nobufs; |
948 | object = hlist_entry(cookie->backing_objects.first, | |
949 | struct fscache_object, cookie_link); | |
950 | if (test_bit(FSCACHE_IOERROR, &object->cache->flags)) | |
951 | goto nobufs; | |
952 | ||
953 | /* add the page to the pending-storage radix tree on the backing | |
954 | * object */ | |
955 | spin_lock(&object->lock); | |
1bccf513 | 956 | spin_lock(&cookie->stores_lock); |
b5108822 DH |
957 | |
958 | _debug("store limit %llx", (unsigned long long) object->store_limit); | |
959 | ||
960 | ret = radix_tree_insert(&cookie->stores, page->index, page); | |
961 | if (ret < 0) { | |
962 | if (ret == -EEXIST) | |
963 | goto already_queued; | |
964 | _debug("insert failed %d", ret); | |
965 | goto nobufs_unlock_obj; | |
966 | } | |
967 | ||
968 | radix_tree_tag_set(&cookie->stores, page->index, | |
969 | FSCACHE_COOKIE_PENDING_TAG); | |
970 | page_cache_get(page); | |
971 | ||
972 | /* we only want one writer at a time, but we do need to queue new | |
973 | * writers after exclusive ops */ | |
974 | if (test_and_set_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags)) | |
975 | goto already_pending; | |
976 | ||
1bccf513 | 977 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
978 | spin_unlock(&object->lock); |
979 | ||
980 | op->op.debug_id = atomic_inc_return(&fscache_op_debug_id); | |
981 | op->store_limit = object->store_limit; | |
982 | ||
8fb883f3 | 983 | __fscache_use_cookie(cookie); |
b5108822 DH |
984 | if (fscache_submit_op(object, &op->op) < 0) |
985 | goto submit_failed; | |
986 | ||
987 | spin_unlock(&cookie->lock); | |
988 | radix_tree_preload_end(); | |
989 | fscache_stat(&fscache_n_store_ops); | |
990 | fscache_stat(&fscache_n_stores_ok); | |
991 | ||
8af7c124 | 992 | /* the work queue now carries its own ref on the object */ |
b5108822 DH |
993 | fscache_put_operation(&op->op); |
994 | _leave(" = 0"); | |
995 | return 0; | |
996 | ||
997 | already_queued: | |
998 | fscache_stat(&fscache_n_stores_again); | |
999 | already_pending: | |
1bccf513 | 1000 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
1001 | spin_unlock(&object->lock); |
1002 | spin_unlock(&cookie->lock); | |
1003 | radix_tree_preload_end(); | |
1004 | kfree(op); | |
1005 | fscache_stat(&fscache_n_stores_ok); | |
1006 | _leave(" = 0"); | |
1007 | return 0; | |
1008 | ||
1009 | submit_failed: | |
1bccf513 | 1010 | spin_lock(&cookie->stores_lock); |
b5108822 | 1011 | radix_tree_delete(&cookie->stores, page->index); |
1bccf513 | 1012 | spin_unlock(&cookie->stores_lock); |
8fb883f3 | 1013 | wake_cookie = __fscache_unuse_cookie(cookie); |
b5108822 DH |
1014 | page_cache_release(page); |
1015 | ret = -ENOBUFS; | |
1016 | goto nobufs; | |
1017 | ||
1018 | nobufs_unlock_obj: | |
1147d0f9 | 1019 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
1020 | spin_unlock(&object->lock); |
1021 | nobufs: | |
1022 | spin_unlock(&cookie->lock); | |
1023 | radix_tree_preload_end(); | |
1024 | kfree(op); | |
8fb883f3 DH |
1025 | if (wake_cookie) |
1026 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
1027 | fscache_stat(&fscache_n_stores_nobufs); |
1028 | _leave(" = -ENOBUFS"); | |
1029 | return -ENOBUFS; | |
1030 | ||
1031 | nomem_free: | |
1032 | kfree(op); | |
1033 | nomem: | |
1034 | fscache_stat(&fscache_n_stores_oom); | |
1035 | _leave(" = -ENOMEM"); | |
1036 | return -ENOMEM; | |
1037 | } | |
1038 | EXPORT_SYMBOL(__fscache_write_page); | |
1039 | ||
1040 | /* | |
1041 | * remove a page from the cache | |
1042 | */ | |
1043 | void __fscache_uncache_page(struct fscache_cookie *cookie, struct page *page) | |
1044 | { | |
1045 | struct fscache_object *object; | |
1046 | ||
1047 | _enter(",%p", page); | |
1048 | ||
1049 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
1050 | ASSERTCMP(page, !=, NULL); | |
1051 | ||
1052 | fscache_stat(&fscache_n_uncaches); | |
1053 | ||
1054 | /* cache withdrawal may beat us to it */ | |
1055 | if (!PageFsCache(page)) | |
1056 | goto done; | |
1057 | ||
1058 | /* get the object */ | |
1059 | spin_lock(&cookie->lock); | |
1060 | ||
1061 | if (hlist_empty(&cookie->backing_objects)) { | |
1062 | ClearPageFsCache(page); | |
1063 | goto done_unlock; | |
1064 | } | |
1065 | ||
1066 | object = hlist_entry(cookie->backing_objects.first, | |
1067 | struct fscache_object, cookie_link); | |
1068 | ||
1069 | /* there might now be stuff on disk we could read */ | |
1070 | clear_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); | |
1071 | ||
1072 | /* only invoke the cache backend if we managed to mark the page | |
1073 | * uncached here; this deals with synchronisation vs withdrawal */ | |
1074 | if (TestClearPageFsCache(page) && | |
1075 | object->cache->ops->uncache_page) { | |
1076 | /* the cache backend releases the cookie lock */ | |
52bd75fd | 1077 | fscache_stat(&fscache_n_cop_uncache_page); |
b5108822 | 1078 | object->cache->ops->uncache_page(object, page); |
52bd75fd | 1079 | fscache_stat_d(&fscache_n_cop_uncache_page); |
b5108822 DH |
1080 | goto done; |
1081 | } | |
1082 | ||
1083 | done_unlock: | |
1084 | spin_unlock(&cookie->lock); | |
1085 | done: | |
1086 | _leave(""); | |
1087 | } | |
1088 | EXPORT_SYMBOL(__fscache_uncache_page); | |
1089 | ||
c4d6d8db DH |
1090 | /** |
1091 | * fscache_mark_page_cached - Mark a page as being cached | |
1092 | * @op: The retrieval op pages are being marked for | |
1093 | * @page: The page to be marked | |
1094 | * | |
1095 | * Mark a netfs page as being cached. After this is called, the netfs | |
1096 | * must call fscache_uncache_page() to remove the mark. | |
1097 | */ | |
1098 | void fscache_mark_page_cached(struct fscache_retrieval *op, struct page *page) | |
1099 | { | |
1100 | struct fscache_cookie *cookie = op->op.object->cookie; | |
1101 | ||
1102 | #ifdef CONFIG_FSCACHE_STATS | |
1103 | atomic_inc(&fscache_n_marks); | |
1104 | #endif | |
1105 | ||
1106 | _debug("- mark %p{%lx}", page, page->index); | |
1107 | if (TestSetPageFsCache(page)) { | |
1108 | static bool once_only; | |
1109 | if (!once_only) { | |
1110 | once_only = true; | |
36dfd116 FF |
1111 | pr_warn("Cookie type %s marked page %lx multiple times\n", |
1112 | cookie->def->name, page->index); | |
c4d6d8db DH |
1113 | } |
1114 | } | |
1115 | ||
1116 | if (cookie->def->mark_page_cached) | |
1117 | cookie->def->mark_page_cached(cookie->netfs_data, | |
1118 | op->mapping, page); | |
1119 | } | |
1120 | EXPORT_SYMBOL(fscache_mark_page_cached); | |
1121 | ||
b5108822 DH |
1122 | /** |
1123 | * fscache_mark_pages_cached - Mark pages as being cached | |
1124 | * @op: The retrieval op pages are being marked for | |
1125 | * @pagevec: The pages to be marked | |
1126 | * | |
1127 | * Mark a bunch of netfs pages as being cached. After this is called, | |
1128 | * the netfs must call fscache_uncache_page() to remove the mark. | |
1129 | */ | |
1130 | void fscache_mark_pages_cached(struct fscache_retrieval *op, | |
1131 | struct pagevec *pagevec) | |
1132 | { | |
b5108822 DH |
1133 | unsigned long loop; |
1134 | ||
c4d6d8db DH |
1135 | for (loop = 0; loop < pagevec->nr; loop++) |
1136 | fscache_mark_page_cached(op, pagevec->pages[loop]); | |
b5108822 | 1137 | |
b5108822 DH |
1138 | pagevec_reinit(pagevec); |
1139 | } | |
1140 | EXPORT_SYMBOL(fscache_mark_pages_cached); | |
c902ce1b DH |
1141 | |
1142 | /* | |
1143 | * Uncache all the pages in an inode that are marked PG_fscache, assuming them | |
1144 | * to be associated with the given cookie. | |
1145 | */ | |
1146 | void __fscache_uncache_all_inode_pages(struct fscache_cookie *cookie, | |
1147 | struct inode *inode) | |
1148 | { | |
1149 | struct address_space *mapping = inode->i_mapping; | |
1150 | struct pagevec pvec; | |
1151 | pgoff_t next; | |
1152 | int i; | |
1153 | ||
1154 | _enter("%p,%p", cookie, inode); | |
1155 | ||
1156 | if (!mapping || mapping->nrpages == 0) { | |
1157 | _leave(" [no pages]"); | |
1158 | return; | |
1159 | } | |
1160 | ||
1161 | pagevec_init(&pvec, 0); | |
1162 | next = 0; | |
b307d465 JB |
1163 | do { |
1164 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) | |
1165 | break; | |
c902ce1b DH |
1166 | for (i = 0; i < pagevec_count(&pvec); i++) { |
1167 | struct page *page = pvec.pages[i]; | |
b307d465 | 1168 | next = page->index; |
c902ce1b DH |
1169 | if (PageFsCache(page)) { |
1170 | __fscache_wait_on_page_write(cookie, page); | |
1171 | __fscache_uncache_page(cookie, page); | |
1172 | } | |
1173 | } | |
1174 | pagevec_release(&pvec); | |
1175 | cond_resched(); | |
b307d465 | 1176 | } while (++next); |
c902ce1b DH |
1177 | |
1178 | _leave(""); | |
1179 | } | |
1180 | EXPORT_SYMBOL(__fscache_uncache_all_inode_pages); |