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 | ||
9776de96 MT |
46 | /* |
47 | * wait for a page to finish being written to the cache. Put a timeout here | |
48 | * since we might be called recursively via parent fs. | |
49 | */ | |
50 | static | |
51 | bool release_page_wait_timeout(struct fscache_cookie *cookie, struct page *page) | |
52 | { | |
53 | wait_queue_head_t *wq = bit_waitqueue(&cookie->flags, 0); | |
54 | ||
55 | return wait_event_timeout(*wq, !__fscache_check_page_write(cookie, page), | |
56 | HZ); | |
57 | } | |
58 | ||
201a1542 DH |
59 | /* |
60 | * decide whether a page can be released, possibly by cancelling a store to it | |
61 | * - we're allowed to sleep if __GFP_WAIT is flagged | |
62 | */ | |
63 | bool __fscache_maybe_release_page(struct fscache_cookie *cookie, | |
64 | struct page *page, | |
65 | gfp_t gfp) | |
66 | { | |
67 | struct page *xpage; | |
68 | void *val; | |
69 | ||
70 | _enter("%p,%p,%x", cookie, page, gfp); | |
71 | ||
8c209ce7 | 72 | try_again: |
201a1542 DH |
73 | rcu_read_lock(); |
74 | val = radix_tree_lookup(&cookie->stores, page->index); | |
75 | if (!val) { | |
76 | rcu_read_unlock(); | |
77 | fscache_stat(&fscache_n_store_vmscan_not_storing); | |
78 | __fscache_uncache_page(cookie, page); | |
79 | return true; | |
80 | } | |
81 | ||
82 | /* see if the page is actually undergoing storage - if so we can't get | |
83 | * rid of it till the cache has finished with it */ | |
84 | if (radix_tree_tag_get(&cookie->stores, page->index, | |
85 | FSCACHE_COOKIE_STORING_TAG)) { | |
86 | rcu_read_unlock(); | |
87 | goto page_busy; | |
88 | } | |
89 | ||
90 | /* the page is pending storage, so we attempt to cancel the store and | |
91 | * discard the store request so that the page can be reclaimed */ | |
92 | spin_lock(&cookie->stores_lock); | |
93 | rcu_read_unlock(); | |
94 | ||
95 | if (radix_tree_tag_get(&cookie->stores, page->index, | |
96 | FSCACHE_COOKIE_STORING_TAG)) { | |
97 | /* the page started to undergo storage whilst we were looking, | |
98 | * so now we can only wait or return */ | |
99 | spin_unlock(&cookie->stores_lock); | |
100 | goto page_busy; | |
101 | } | |
102 | ||
103 | xpage = radix_tree_delete(&cookie->stores, page->index); | |
104 | spin_unlock(&cookie->stores_lock); | |
105 | ||
106 | if (xpage) { | |
107 | fscache_stat(&fscache_n_store_vmscan_cancelled); | |
108 | fscache_stat(&fscache_n_store_radix_deletes); | |
109 | ASSERTCMP(xpage, ==, page); | |
110 | } else { | |
111 | fscache_stat(&fscache_n_store_vmscan_gone); | |
112 | } | |
113 | ||
114 | wake_up_bit(&cookie->flags, 0); | |
115 | if (xpage) | |
116 | page_cache_release(xpage); | |
117 | __fscache_uncache_page(cookie, page); | |
118 | return true; | |
119 | ||
120 | page_busy: | |
8c209ce7 DH |
121 | /* We will wait here if we're allowed to, but that could deadlock the |
122 | * allocator as the work threads writing to the cache may all end up | |
123 | * sleeping on memory allocation, so we may need to impose a timeout | |
124 | * too. */ | |
0c59a95d | 125 | if (!(gfp & __GFP_WAIT) || !(gfp & __GFP_FS)) { |
8c209ce7 DH |
126 | fscache_stat(&fscache_n_store_vmscan_busy); |
127 | return false; | |
128 | } | |
129 | ||
130 | fscache_stat(&fscache_n_store_vmscan_wait); | |
9776de96 MT |
131 | if (!release_page_wait_timeout(cookie, page)) |
132 | _debug("fscache writeout timeout page: %p{%lx}", | |
133 | page, page->index); | |
134 | ||
8c209ce7 DH |
135 | gfp &= ~__GFP_WAIT; |
136 | goto try_again; | |
201a1542 DH |
137 | } |
138 | EXPORT_SYMBOL(__fscache_maybe_release_page); | |
139 | ||
b5108822 DH |
140 | /* |
141 | * note that a page has finished being written to the cache | |
142 | */ | |
1bccf513 DH |
143 | static void fscache_end_page_write(struct fscache_object *object, |
144 | struct page *page) | |
b5108822 | 145 | { |
1bccf513 DH |
146 | struct fscache_cookie *cookie; |
147 | struct page *xpage = NULL; | |
b5108822 | 148 | |
1bccf513 DH |
149 | spin_lock(&object->lock); |
150 | cookie = object->cookie; | |
151 | if (cookie) { | |
152 | /* delete the page from the tree if it is now no longer | |
153 | * pending */ | |
154 | spin_lock(&cookie->stores_lock); | |
201a1542 DH |
155 | radix_tree_tag_clear(&cookie->stores, page->index, |
156 | FSCACHE_COOKIE_STORING_TAG); | |
285e728b DH |
157 | if (!radix_tree_tag_get(&cookie->stores, page->index, |
158 | FSCACHE_COOKIE_PENDING_TAG)) { | |
159 | fscache_stat(&fscache_n_store_radix_deletes); | |
160 | xpage = radix_tree_delete(&cookie->stores, page->index); | |
161 | } | |
1bccf513 DH |
162 | spin_unlock(&cookie->stores_lock); |
163 | wake_up_bit(&cookie->flags, 0); | |
164 | } | |
165 | spin_unlock(&object->lock); | |
166 | if (xpage) | |
167 | page_cache_release(xpage); | |
b5108822 DH |
168 | } |
169 | ||
170 | /* | |
171 | * actually apply the changed attributes to a cache object | |
172 | */ | |
173 | static void fscache_attr_changed_op(struct fscache_operation *op) | |
174 | { | |
175 | struct fscache_object *object = op->object; | |
440f0aff | 176 | int ret; |
b5108822 DH |
177 | |
178 | _enter("{OBJ%x OP%x}", object->debug_id, op->debug_id); | |
179 | ||
180 | fscache_stat(&fscache_n_attr_changed_calls); | |
181 | ||
8fb883f3 | 182 | if (fscache_object_is_active(object)) { |
52bd75fd | 183 | fscache_stat(&fscache_n_cop_attr_changed); |
440f0aff | 184 | ret = object->cache->ops->attr_changed(object); |
52bd75fd | 185 | fscache_stat_d(&fscache_n_cop_attr_changed); |
440f0aff DH |
186 | if (ret < 0) |
187 | fscache_abort_object(object); | |
188 | } | |
b5108822 | 189 | |
1f372dff | 190 | fscache_op_complete(op, true); |
b5108822 DH |
191 | _leave(""); |
192 | } | |
193 | ||
194 | /* | |
195 | * notification that the attributes on an object have changed | |
196 | */ | |
197 | int __fscache_attr_changed(struct fscache_cookie *cookie) | |
198 | { | |
199 | struct fscache_operation *op; | |
200 | struct fscache_object *object; | |
3e1199dc | 201 | bool wake_cookie = false; |
b5108822 DH |
202 | |
203 | _enter("%p", cookie); | |
204 | ||
205 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
206 | ||
207 | fscache_stat(&fscache_n_attr_changed); | |
208 | ||
209 | op = kzalloc(sizeof(*op), GFP_KERNEL); | |
210 | if (!op) { | |
211 | fscache_stat(&fscache_n_attr_changed_nomem); | |
212 | _leave(" = -ENOMEM"); | |
213 | return -ENOMEM; | |
214 | } | |
215 | ||
8af7c124 | 216 | fscache_operation_init(op, fscache_attr_changed_op, NULL); |
8fb883f3 DH |
217 | op->flags = FSCACHE_OP_ASYNC | |
218 | (1 << FSCACHE_OP_EXCLUSIVE) | | |
219 | (1 << FSCACHE_OP_UNUSE_COOKIE); | |
b5108822 DH |
220 | |
221 | spin_lock(&cookie->lock); | |
222 | ||
94d30ae9 DH |
223 | if (!fscache_cookie_enabled(cookie) || |
224 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
225 | goto nobufs; |
226 | object = hlist_entry(cookie->backing_objects.first, | |
227 | struct fscache_object, cookie_link); | |
228 | ||
8fb883f3 | 229 | __fscache_use_cookie(cookie); |
b5108822 | 230 | if (fscache_submit_exclusive_op(object, op) < 0) |
3e1199dc | 231 | goto nobufs_dec; |
b5108822 DH |
232 | spin_unlock(&cookie->lock); |
233 | fscache_stat(&fscache_n_attr_changed_ok); | |
234 | fscache_put_operation(op); | |
235 | _leave(" = 0"); | |
236 | return 0; | |
237 | ||
3e1199dc | 238 | nobufs_dec: |
8fb883f3 | 239 | wake_cookie = __fscache_unuse_cookie(cookie); |
3e1199dc | 240 | nobufs: |
b5108822 DH |
241 | spin_unlock(&cookie->lock); |
242 | kfree(op); | |
8fb883f3 DH |
243 | if (wake_cookie) |
244 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
245 | fscache_stat(&fscache_n_attr_changed_nobufs); |
246 | _leave(" = %d", -ENOBUFS); | |
247 | return -ENOBUFS; | |
248 | } | |
249 | EXPORT_SYMBOL(__fscache_attr_changed); | |
250 | ||
b5108822 DH |
251 | /* |
252 | * release a retrieval op reference | |
253 | */ | |
254 | static void fscache_release_retrieval_op(struct fscache_operation *_op) | |
255 | { | |
256 | struct fscache_retrieval *op = | |
257 | container_of(_op, struct fscache_retrieval, op); | |
258 | ||
259 | _enter("{OP%x}", op->op.debug_id); | |
260 | ||
1bb4b7f9 | 261 | ASSERTCMP(atomic_read(&op->n_pages), ==, 0); |
9f10523f | 262 | |
b5108822 DH |
263 | fscache_hist(fscache_retrieval_histogram, op->start_time); |
264 | if (op->context) | |
265 | fscache_put_context(op->op.object->cookie, op->context); | |
266 | ||
267 | _leave(""); | |
268 | } | |
269 | ||
270 | /* | |
271 | * allocate a retrieval op | |
272 | */ | |
273 | static struct fscache_retrieval *fscache_alloc_retrieval( | |
1362729b | 274 | struct fscache_cookie *cookie, |
b5108822 DH |
275 | struct address_space *mapping, |
276 | fscache_rw_complete_t end_io_func, | |
277 | void *context) | |
278 | { | |
279 | struct fscache_retrieval *op; | |
280 | ||
281 | /* allocate a retrieval operation and attempt to submit it */ | |
282 | op = kzalloc(sizeof(*op), GFP_NOIO); | |
283 | if (!op) { | |
284 | fscache_stat(&fscache_n_retrievals_nomem); | |
285 | return NULL; | |
286 | } | |
287 | ||
8af7c124 | 288 | fscache_operation_init(&op->op, NULL, fscache_release_retrieval_op); |
1362729b DH |
289 | op->op.flags = FSCACHE_OP_MYTHREAD | |
290 | (1UL << FSCACHE_OP_WAITING) | | |
291 | (1UL << FSCACHE_OP_UNUSE_COOKIE); | |
b5108822 DH |
292 | op->mapping = mapping; |
293 | op->end_io_func = end_io_func; | |
294 | op->context = context; | |
295 | op->start_time = jiffies; | |
b5108822 DH |
296 | INIT_LIST_HEAD(&op->to_do); |
297 | return op; | |
298 | } | |
299 | ||
300 | /* | |
301 | * wait for a deferred lookup to complete | |
302 | */ | |
da9803bc | 303 | int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie) |
b5108822 DH |
304 | { |
305 | unsigned long jif; | |
306 | ||
307 | _enter(""); | |
308 | ||
309 | if (!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) { | |
310 | _leave(" = 0 [imm]"); | |
311 | return 0; | |
312 | } | |
313 | ||
314 | fscache_stat(&fscache_n_retrievals_wait); | |
315 | ||
316 | jif = jiffies; | |
317 | if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP, | |
b5108822 DH |
318 | TASK_INTERRUPTIBLE) != 0) { |
319 | fscache_stat(&fscache_n_retrievals_intr); | |
320 | _leave(" = -ERESTARTSYS"); | |
321 | return -ERESTARTSYS; | |
322 | } | |
323 | ||
324 | ASSERT(!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)); | |
325 | ||
326 | smp_rmb(); | |
327 | fscache_hist(fscache_retrieval_delay_histogram, jif); | |
328 | _leave(" = 0 [dly]"); | |
329 | return 0; | |
330 | } | |
331 | ||
91c7fbbf DH |
332 | /* |
333 | * Handle cancellation of a pending retrieval op | |
334 | */ | |
335 | static void fscache_do_cancel_retrieval(struct fscache_operation *_op) | |
336 | { | |
337 | struct fscache_retrieval *op = | |
338 | container_of(_op, struct fscache_retrieval, op); | |
339 | ||
1bb4b7f9 | 340 | atomic_set(&op->n_pages, 0); |
91c7fbbf DH |
341 | } |
342 | ||
60d543ca DH |
343 | /* |
344 | * wait for an object to become active (or dead) | |
345 | */ | |
da9803bc DH |
346 | int fscache_wait_for_operation_activation(struct fscache_object *object, |
347 | struct fscache_operation *op, | |
348 | atomic_t *stat_op_waits, | |
349 | atomic_t *stat_object_dead, | |
350 | void (*do_cancel)(struct fscache_operation *)) | |
60d543ca DH |
351 | { |
352 | int ret; | |
353 | ||
da9803bc | 354 | if (!test_bit(FSCACHE_OP_WAITING, &op->flags)) |
60d543ca DH |
355 | goto check_if_dead; |
356 | ||
357 | _debug(">>> WT"); | |
da9803bc DH |
358 | if (stat_op_waits) |
359 | fscache_stat(stat_op_waits); | |
360 | if (wait_on_bit(&op->flags, FSCACHE_OP_WAITING, | |
9c04caa8 | 361 | TASK_INTERRUPTIBLE) != 0) { |
da9803bc | 362 | ret = fscache_cancel_op(op, do_cancel); |
60d543ca DH |
363 | if (ret == 0) |
364 | return -ERESTARTSYS; | |
365 | ||
366 | /* it's been removed from the pending queue by another party, | |
367 | * so we should get to run shortly */ | |
da9803bc | 368 | wait_on_bit(&op->flags, FSCACHE_OP_WAITING, |
74316201 | 369 | TASK_UNINTERRUPTIBLE); |
60d543ca DH |
370 | } |
371 | _debug("<<< GO"); | |
372 | ||
373 | check_if_dead: | |
da9803bc DH |
374 | if (op->state == FSCACHE_OP_ST_CANCELLED) { |
375 | if (stat_object_dead) | |
376 | fscache_stat(stat_object_dead); | |
9f10523f DH |
377 | _leave(" = -ENOBUFS [cancelled]"); |
378 | return -ENOBUFS; | |
379 | } | |
87021526 DH |
380 | if (unlikely(fscache_object_is_dying(object) || |
381 | fscache_cache_is_broken(object))) { | |
382 | enum fscache_operation_state state = op->state; | |
da9803bc DH |
383 | fscache_cancel_op(op, do_cancel); |
384 | if (stat_object_dead) | |
385 | fscache_stat(stat_object_dead); | |
87021526 | 386 | _leave(" = -ENOBUFS [obj dead %d]", state); |
60d543ca DH |
387 | return -ENOBUFS; |
388 | } | |
389 | return 0; | |
390 | } | |
391 | ||
b5108822 DH |
392 | /* |
393 | * read a page from the cache or allocate a block in which to store it | |
394 | * - we return: | |
395 | * -ENOMEM - out of memory, nothing done | |
396 | * -ERESTARTSYS - interrupted | |
397 | * -ENOBUFS - no backing object available in which to cache the block | |
398 | * -ENODATA - no data available in the backing object for this block | |
399 | * 0 - dispatched a read - it'll call end_io_func() when finished | |
400 | */ | |
401 | int __fscache_read_or_alloc_page(struct fscache_cookie *cookie, | |
402 | struct page *page, | |
403 | fscache_rw_complete_t end_io_func, | |
404 | void *context, | |
405 | gfp_t gfp) | |
406 | { | |
407 | struct fscache_retrieval *op; | |
408 | struct fscache_object *object; | |
8fb883f3 | 409 | bool wake_cookie = false; |
b5108822 DH |
410 | int ret; |
411 | ||
412 | _enter("%p,%p,,,", cookie, page); | |
413 | ||
414 | fscache_stat(&fscache_n_retrievals); | |
415 | ||
416 | if (hlist_empty(&cookie->backing_objects)) | |
417 | goto nobufs; | |
418 | ||
ef778e7a DH |
419 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
420 | _leave(" = -ENOBUFS [invalidating]"); | |
421 | return -ENOBUFS; | |
422 | } | |
423 | ||
b5108822 DH |
424 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); |
425 | ASSERTCMP(page, !=, NULL); | |
426 | ||
427 | if (fscache_wait_for_deferred_lookup(cookie) < 0) | |
428 | return -ERESTARTSYS; | |
429 | ||
1362729b | 430 | op = fscache_alloc_retrieval(cookie, page->mapping, |
94d30ae9 | 431 | end_io_func, context); |
b5108822 DH |
432 | if (!op) { |
433 | _leave(" = -ENOMEM"); | |
434 | return -ENOMEM; | |
435 | } | |
1bb4b7f9 | 436 | atomic_set(&op->n_pages, 1); |
b5108822 DH |
437 | |
438 | spin_lock(&cookie->lock); | |
439 | ||
94d30ae9 DH |
440 | if (!fscache_cookie_enabled(cookie) || |
441 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
442 | goto nobufs_unlock; |
443 | object = hlist_entry(cookie->backing_objects.first, | |
444 | struct fscache_object, cookie_link); | |
445 | ||
caaef690 | 446 | ASSERT(test_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)); |
b5108822 | 447 | |
8fb883f3 | 448 | __fscache_use_cookie(cookie); |
4fbf4291 | 449 | atomic_inc(&object->n_reads); |
9f10523f | 450 | __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags); |
4fbf4291 | 451 | |
b5108822 | 452 | if (fscache_submit_op(object, &op->op) < 0) |
9f10523f | 453 | goto nobufs_unlock_dec; |
b5108822 DH |
454 | spin_unlock(&cookie->lock); |
455 | ||
456 | fscache_stat(&fscache_n_retrieval_ops); | |
457 | ||
458 | /* pin the netfs read context in case we need to do the actual netfs | |
459 | * read because we've encountered a cache read failure */ | |
460 | fscache_get_context(object->cookie, op->context); | |
461 | ||
462 | /* we wait for the operation to become active, and then process it | |
463 | * *here*, in this thread, and not in the thread pool */ | |
da9803bc DH |
464 | ret = fscache_wait_for_operation_activation( |
465 | object, &op->op, | |
60d543ca | 466 | __fscache_stat(&fscache_n_retrieval_op_waits), |
da9803bc DH |
467 | __fscache_stat(&fscache_n_retrievals_object_dead), |
468 | fscache_do_cancel_retrieval); | |
60d543ca DH |
469 | if (ret < 0) |
470 | goto error; | |
b5108822 DH |
471 | |
472 | /* ask the cache to honour the operation */ | |
473 | if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) { | |
52bd75fd | 474 | fscache_stat(&fscache_n_cop_allocate_page); |
b5108822 | 475 | ret = object->cache->ops->allocate_page(op, page, gfp); |
52bd75fd | 476 | fscache_stat_d(&fscache_n_cop_allocate_page); |
b5108822 DH |
477 | if (ret == 0) |
478 | ret = -ENODATA; | |
479 | } else { | |
52bd75fd | 480 | fscache_stat(&fscache_n_cop_read_or_alloc_page); |
b5108822 | 481 | ret = object->cache->ops->read_or_alloc_page(op, page, gfp); |
52bd75fd | 482 | fscache_stat_d(&fscache_n_cop_read_or_alloc_page); |
b5108822 DH |
483 | } |
484 | ||
5753c441 | 485 | error: |
b5108822 DH |
486 | if (ret == -ENOMEM) |
487 | fscache_stat(&fscache_n_retrievals_nomem); | |
488 | else if (ret == -ERESTARTSYS) | |
489 | fscache_stat(&fscache_n_retrievals_intr); | |
490 | else if (ret == -ENODATA) | |
491 | fscache_stat(&fscache_n_retrievals_nodata); | |
492 | else if (ret < 0) | |
493 | fscache_stat(&fscache_n_retrievals_nobufs); | |
494 | else | |
495 | fscache_stat(&fscache_n_retrievals_ok); | |
496 | ||
497 | fscache_put_retrieval(op); | |
498 | _leave(" = %d", ret); | |
499 | return ret; | |
500 | ||
9f10523f DH |
501 | nobufs_unlock_dec: |
502 | atomic_dec(&object->n_reads); | |
8fb883f3 | 503 | wake_cookie = __fscache_unuse_cookie(cookie); |
b5108822 DH |
504 | nobufs_unlock: |
505 | spin_unlock(&cookie->lock); | |
8fb883f3 DH |
506 | if (wake_cookie) |
507 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
508 | kfree(op); |
509 | nobufs: | |
510 | fscache_stat(&fscache_n_retrievals_nobufs); | |
511 | _leave(" = -ENOBUFS"); | |
512 | return -ENOBUFS; | |
513 | } | |
514 | EXPORT_SYMBOL(__fscache_read_or_alloc_page); | |
515 | ||
516 | /* | |
517 | * read a list of page from the cache or allocate a block in which to store | |
518 | * them | |
519 | * - we return: | |
520 | * -ENOMEM - out of memory, some pages may be being read | |
521 | * -ERESTARTSYS - interrupted, some pages may be being read | |
522 | * -ENOBUFS - no backing object or space available in which to cache any | |
523 | * pages not being read | |
524 | * -ENODATA - no data available in the backing object for some or all of | |
525 | * the pages | |
526 | * 0 - dispatched a read on all pages | |
527 | * | |
528 | * end_io_func() will be called for each page read from the cache as it is | |
529 | * finishes being read | |
530 | * | |
531 | * any pages for which a read is dispatched will be removed from pages and | |
532 | * nr_pages | |
533 | */ | |
534 | int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie, | |
535 | struct address_space *mapping, | |
536 | struct list_head *pages, | |
537 | unsigned *nr_pages, | |
538 | fscache_rw_complete_t end_io_func, | |
539 | void *context, | |
540 | gfp_t gfp) | |
541 | { | |
b5108822 DH |
542 | struct fscache_retrieval *op; |
543 | struct fscache_object *object; | |
8fb883f3 | 544 | bool wake_cookie = false; |
b5108822 DH |
545 | int ret; |
546 | ||
547 | _enter("%p,,%d,,,", cookie, *nr_pages); | |
548 | ||
549 | fscache_stat(&fscache_n_retrievals); | |
550 | ||
551 | if (hlist_empty(&cookie->backing_objects)) | |
552 | goto nobufs; | |
553 | ||
ef778e7a DH |
554 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
555 | _leave(" = -ENOBUFS [invalidating]"); | |
556 | return -ENOBUFS; | |
557 | } | |
558 | ||
b5108822 DH |
559 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); |
560 | ASSERTCMP(*nr_pages, >, 0); | |
561 | ASSERT(!list_empty(pages)); | |
562 | ||
563 | if (fscache_wait_for_deferred_lookup(cookie) < 0) | |
564 | return -ERESTARTSYS; | |
565 | ||
1362729b | 566 | op = fscache_alloc_retrieval(cookie, mapping, end_io_func, context); |
b5108822 DH |
567 | if (!op) |
568 | return -ENOMEM; | |
1bb4b7f9 | 569 | atomic_set(&op->n_pages, *nr_pages); |
b5108822 DH |
570 | |
571 | spin_lock(&cookie->lock); | |
572 | ||
94d30ae9 DH |
573 | if (!fscache_cookie_enabled(cookie) || |
574 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
575 | goto nobufs_unlock; |
576 | object = hlist_entry(cookie->backing_objects.first, | |
577 | struct fscache_object, cookie_link); | |
578 | ||
8fb883f3 | 579 | __fscache_use_cookie(cookie); |
4fbf4291 | 580 | atomic_inc(&object->n_reads); |
9f10523f | 581 | __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags); |
4fbf4291 | 582 | |
b5108822 | 583 | if (fscache_submit_op(object, &op->op) < 0) |
9f10523f | 584 | goto nobufs_unlock_dec; |
b5108822 DH |
585 | spin_unlock(&cookie->lock); |
586 | ||
587 | fscache_stat(&fscache_n_retrieval_ops); | |
588 | ||
589 | /* pin the netfs read context in case we need to do the actual netfs | |
590 | * read because we've encountered a cache read failure */ | |
591 | fscache_get_context(object->cookie, op->context); | |
592 | ||
593 | /* we wait for the operation to become active, and then process it | |
594 | * *here*, in this thread, and not in the thread pool */ | |
da9803bc DH |
595 | ret = fscache_wait_for_operation_activation( |
596 | object, &op->op, | |
60d543ca | 597 | __fscache_stat(&fscache_n_retrieval_op_waits), |
da9803bc DH |
598 | __fscache_stat(&fscache_n_retrievals_object_dead), |
599 | fscache_do_cancel_retrieval); | |
60d543ca DH |
600 | if (ret < 0) |
601 | goto error; | |
b5108822 DH |
602 | |
603 | /* ask the cache to honour the operation */ | |
52bd75fd DH |
604 | if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) { |
605 | fscache_stat(&fscache_n_cop_allocate_pages); | |
606 | ret = object->cache->ops->allocate_pages( | |
607 | op, pages, nr_pages, gfp); | |
608 | fscache_stat_d(&fscache_n_cop_allocate_pages); | |
609 | } else { | |
610 | fscache_stat(&fscache_n_cop_read_or_alloc_pages); | |
611 | ret = object->cache->ops->read_or_alloc_pages( | |
612 | op, pages, nr_pages, gfp); | |
613 | fscache_stat_d(&fscache_n_cop_read_or_alloc_pages); | |
614 | } | |
b5108822 | 615 | |
5753c441 | 616 | error: |
b5108822 DH |
617 | if (ret == -ENOMEM) |
618 | fscache_stat(&fscache_n_retrievals_nomem); | |
619 | else if (ret == -ERESTARTSYS) | |
620 | fscache_stat(&fscache_n_retrievals_intr); | |
621 | else if (ret == -ENODATA) | |
622 | fscache_stat(&fscache_n_retrievals_nodata); | |
623 | else if (ret < 0) | |
624 | fscache_stat(&fscache_n_retrievals_nobufs); | |
625 | else | |
626 | fscache_stat(&fscache_n_retrievals_ok); | |
627 | ||
628 | fscache_put_retrieval(op); | |
629 | _leave(" = %d", ret); | |
630 | return ret; | |
631 | ||
9f10523f DH |
632 | nobufs_unlock_dec: |
633 | atomic_dec(&object->n_reads); | |
8fb883f3 | 634 | wake_cookie = __fscache_unuse_cookie(cookie); |
b5108822 DH |
635 | nobufs_unlock: |
636 | spin_unlock(&cookie->lock); | |
637 | kfree(op); | |
8fb883f3 DH |
638 | if (wake_cookie) |
639 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
640 | nobufs: |
641 | fscache_stat(&fscache_n_retrievals_nobufs); | |
642 | _leave(" = -ENOBUFS"); | |
643 | return -ENOBUFS; | |
644 | } | |
645 | EXPORT_SYMBOL(__fscache_read_or_alloc_pages); | |
646 | ||
647 | /* | |
648 | * allocate a block in the cache on which to store a page | |
649 | * - we return: | |
650 | * -ENOMEM - out of memory, nothing done | |
651 | * -ERESTARTSYS - interrupted | |
652 | * -ENOBUFS - no backing object available in which to cache the block | |
653 | * 0 - block allocated | |
654 | */ | |
655 | int __fscache_alloc_page(struct fscache_cookie *cookie, | |
656 | struct page *page, | |
657 | gfp_t gfp) | |
658 | { | |
659 | struct fscache_retrieval *op; | |
660 | struct fscache_object *object; | |
8fb883f3 | 661 | bool wake_cookie = false; |
b5108822 DH |
662 | int ret; |
663 | ||
664 | _enter("%p,%p,,,", cookie, page); | |
665 | ||
666 | fscache_stat(&fscache_n_allocs); | |
667 | ||
668 | if (hlist_empty(&cookie->backing_objects)) | |
669 | goto nobufs; | |
670 | ||
671 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
672 | ASSERTCMP(page, !=, NULL); | |
673 | ||
ef778e7a DH |
674 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
675 | _leave(" = -ENOBUFS [invalidating]"); | |
676 | return -ENOBUFS; | |
677 | } | |
678 | ||
b5108822 DH |
679 | if (fscache_wait_for_deferred_lookup(cookie) < 0) |
680 | return -ERESTARTSYS; | |
681 | ||
1362729b | 682 | op = fscache_alloc_retrieval(cookie, page->mapping, NULL, NULL); |
b5108822 DH |
683 | if (!op) |
684 | return -ENOMEM; | |
1bb4b7f9 | 685 | atomic_set(&op->n_pages, 1); |
b5108822 DH |
686 | |
687 | spin_lock(&cookie->lock); | |
688 | ||
94d30ae9 DH |
689 | if (!fscache_cookie_enabled(cookie) || |
690 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
691 | goto nobufs_unlock; |
692 | object = hlist_entry(cookie->backing_objects.first, | |
693 | struct fscache_object, cookie_link); | |
694 | ||
8fb883f3 | 695 | __fscache_use_cookie(cookie); |
b5108822 | 696 | if (fscache_submit_op(object, &op->op) < 0) |
8fb883f3 | 697 | goto nobufs_unlock_dec; |
b5108822 DH |
698 | spin_unlock(&cookie->lock); |
699 | ||
700 | fscache_stat(&fscache_n_alloc_ops); | |
701 | ||
da9803bc DH |
702 | ret = fscache_wait_for_operation_activation( |
703 | object, &op->op, | |
60d543ca | 704 | __fscache_stat(&fscache_n_alloc_op_waits), |
da9803bc DH |
705 | __fscache_stat(&fscache_n_allocs_object_dead), |
706 | fscache_do_cancel_retrieval); | |
60d543ca DH |
707 | if (ret < 0) |
708 | goto error; | |
b5108822 DH |
709 | |
710 | /* ask the cache to honour the operation */ | |
52bd75fd | 711 | fscache_stat(&fscache_n_cop_allocate_page); |
b5108822 | 712 | ret = object->cache->ops->allocate_page(op, page, gfp); |
52bd75fd | 713 | fscache_stat_d(&fscache_n_cop_allocate_page); |
b5108822 | 714 | |
5753c441 DH |
715 | error: |
716 | if (ret == -ERESTARTSYS) | |
717 | fscache_stat(&fscache_n_allocs_intr); | |
718 | else if (ret < 0) | |
b5108822 DH |
719 | fscache_stat(&fscache_n_allocs_nobufs); |
720 | else | |
721 | fscache_stat(&fscache_n_allocs_ok); | |
722 | ||
723 | fscache_put_retrieval(op); | |
724 | _leave(" = %d", ret); | |
725 | return ret; | |
726 | ||
8fb883f3 DH |
727 | nobufs_unlock_dec: |
728 | wake_cookie = __fscache_unuse_cookie(cookie); | |
b5108822 DH |
729 | nobufs_unlock: |
730 | spin_unlock(&cookie->lock); | |
731 | kfree(op); | |
8fb883f3 DH |
732 | if (wake_cookie) |
733 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
734 | nobufs: |
735 | fscache_stat(&fscache_n_allocs_nobufs); | |
736 | _leave(" = -ENOBUFS"); | |
737 | return -ENOBUFS; | |
738 | } | |
739 | EXPORT_SYMBOL(__fscache_alloc_page); | |
740 | ||
5a6f282a MT |
741 | /* |
742 | * Unmark pages allocate in the readahead code path (via: | |
743 | * fscache_readpages_or_alloc) after delegating to the base filesystem | |
744 | */ | |
745 | void __fscache_readpages_cancel(struct fscache_cookie *cookie, | |
746 | struct list_head *pages) | |
747 | { | |
748 | struct page *page; | |
749 | ||
750 | list_for_each_entry(page, pages, lru) { | |
751 | if (PageFsCache(page)) | |
752 | __fscache_uncache_page(cookie, page); | |
753 | } | |
754 | } | |
755 | EXPORT_SYMBOL(__fscache_readpages_cancel); | |
756 | ||
b5108822 DH |
757 | /* |
758 | * release a write op reference | |
759 | */ | |
760 | static void fscache_release_write_op(struct fscache_operation *_op) | |
761 | { | |
762 | _enter("{OP%x}", _op->debug_id); | |
763 | } | |
764 | ||
765 | /* | |
766 | * perform the background storage of a page into the cache | |
767 | */ | |
768 | static void fscache_write_op(struct fscache_operation *_op) | |
769 | { | |
770 | struct fscache_storage *op = | |
771 | container_of(_op, struct fscache_storage, op); | |
772 | struct fscache_object *object = op->op.object; | |
1bccf513 | 773 | struct fscache_cookie *cookie; |
b5108822 DH |
774 | struct page *page; |
775 | unsigned n; | |
776 | void *results[1]; | |
777 | int ret; | |
778 | ||
779 | _enter("{OP%x,%d}", op->op.debug_id, atomic_read(&op->op.usage)); | |
780 | ||
b5108822 | 781 | spin_lock(&object->lock); |
1bccf513 | 782 | cookie = object->cookie; |
b5108822 | 783 | |
7ef001e9 DH |
784 | if (!fscache_object_is_active(object)) { |
785 | /* If we get here, then the on-disk cache object likely longer | |
786 | * exists, so we should just cancel this write operation. | |
787 | */ | |
b5108822 | 788 | spin_unlock(&object->lock); |
1f372dff | 789 | fscache_op_complete(&op->op, false); |
7ef001e9 DH |
790 | _leave(" [inactive]"); |
791 | return; | |
792 | } | |
793 | ||
794 | if (!cookie) { | |
795 | /* If we get here, then the cookie belonging to the object was | |
796 | * detached, probably by the cookie being withdrawn due to | |
797 | * memory pressure, which means that the pages we might write | |
798 | * to the cache from no longer exist - therefore, we can just | |
799 | * cancel this write operation. | |
800 | */ | |
801 | spin_unlock(&object->lock); | |
1f372dff | 802 | fscache_op_complete(&op->op, false); |
caaef690 DH |
803 | _leave(" [cancel] op{f=%lx s=%u} obj{s=%s f=%lx}", |
804 | _op->flags, _op->state, object->state->short_name, | |
805 | object->flags); | |
b5108822 DH |
806 | return; |
807 | } | |
808 | ||
1bccf513 DH |
809 | spin_lock(&cookie->stores_lock); |
810 | ||
b5108822 DH |
811 | fscache_stat(&fscache_n_store_calls); |
812 | ||
813 | /* find a page to store */ | |
814 | page = NULL; | |
815 | n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, 1, | |
816 | FSCACHE_COOKIE_PENDING_TAG); | |
817 | if (n != 1) | |
818 | goto superseded; | |
819 | page = results[0]; | |
820 | _debug("gang %d [%lx]", n, page->index); | |
1bccf513 DH |
821 | if (page->index > op->store_limit) { |
822 | fscache_stat(&fscache_n_store_pages_over_limit); | |
b5108822 | 823 | goto superseded; |
1bccf513 | 824 | } |
b5108822 | 825 | |
08a66859 DC |
826 | radix_tree_tag_set(&cookie->stores, page->index, |
827 | FSCACHE_COOKIE_STORING_TAG); | |
828 | radix_tree_tag_clear(&cookie->stores, page->index, | |
829 | FSCACHE_COOKIE_PENDING_TAG); | |
b5108822 | 830 | |
1bccf513 | 831 | spin_unlock(&cookie->stores_lock); |
b5108822 | 832 | spin_unlock(&object->lock); |
b5108822 | 833 | |
08a66859 DC |
834 | fscache_stat(&fscache_n_store_pages); |
835 | fscache_stat(&fscache_n_cop_write_page); | |
836 | ret = object->cache->ops->write_page(op, page); | |
837 | fscache_stat_d(&fscache_n_cop_write_page); | |
08a66859 DC |
838 | fscache_end_page_write(object, page); |
839 | if (ret < 0) { | |
08a66859 | 840 | fscache_abort_object(object); |
1f372dff | 841 | fscache_op_complete(&op->op, true); |
08a66859 DC |
842 | } else { |
843 | fscache_enqueue_operation(&op->op); | |
b5108822 DH |
844 | } |
845 | ||
846 | _leave(""); | |
847 | return; | |
848 | ||
849 | superseded: | |
850 | /* this writer is going away and there aren't any more things to | |
851 | * write */ | |
852 | _debug("cease"); | |
1bccf513 | 853 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
854 | clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags); |
855 | spin_unlock(&object->lock); | |
1f372dff | 856 | fscache_op_complete(&op->op, true); |
b5108822 DH |
857 | _leave(""); |
858 | } | |
859 | ||
ef778e7a DH |
860 | /* |
861 | * Clear the pages pending writing for invalidation | |
862 | */ | |
863 | void fscache_invalidate_writes(struct fscache_cookie *cookie) | |
864 | { | |
865 | struct page *page; | |
866 | void *results[16]; | |
867 | int n, i; | |
868 | ||
869 | _enter(""); | |
870 | ||
ee8be57b SAS |
871 | for (;;) { |
872 | spin_lock(&cookie->stores_lock); | |
873 | n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, | |
874 | ARRAY_SIZE(results), | |
875 | FSCACHE_COOKIE_PENDING_TAG); | |
876 | if (n == 0) { | |
877 | spin_unlock(&cookie->stores_lock); | |
878 | break; | |
879 | } | |
880 | ||
ef778e7a DH |
881 | for (i = n - 1; i >= 0; i--) { |
882 | page = results[i]; | |
883 | radix_tree_delete(&cookie->stores, page->index); | |
884 | } | |
885 | ||
886 | spin_unlock(&cookie->stores_lock); | |
887 | ||
888 | for (i = n - 1; i >= 0; i--) | |
889 | page_cache_release(results[i]); | |
890 | } | |
891 | ||
ef778e7a DH |
892 | _leave(""); |
893 | } | |
894 | ||
b5108822 DH |
895 | /* |
896 | * request a page be stored in the cache | |
897 | * - returns: | |
898 | * -ENOMEM - out of memory, nothing done | |
899 | * -ENOBUFS - no backing object available in which to cache the page | |
900 | * 0 - dispatched a write - it'll call end_io_func() when finished | |
901 | * | |
902 | * if the cookie still has a backing object at this point, that object can be | |
903 | * in one of a few states with respect to storage processing: | |
904 | * | |
905 | * (1) negative lookup, object not yet created (FSCACHE_COOKIE_CREATING is | |
906 | * set) | |
907 | * | |
caaef690 | 908 | * (a) no writes yet |
b5108822 DH |
909 | * |
910 | * (b) writes deferred till post-creation (mark page for writing and | |
911 | * return immediately) | |
912 | * | |
913 | * (2) negative lookup, object created, initial fill being made from netfs | |
b5108822 DH |
914 | * |
915 | * (a) fill point not yet reached this page (mark page for writing and | |
916 | * return) | |
917 | * | |
918 | * (b) fill point passed this page (queue op to store this page) | |
919 | * | |
920 | * (3) object extant (queue op to store this page) | |
921 | * | |
922 | * any other state is invalid | |
923 | */ | |
924 | int __fscache_write_page(struct fscache_cookie *cookie, | |
925 | struct page *page, | |
926 | gfp_t gfp) | |
927 | { | |
928 | struct fscache_storage *op; | |
929 | struct fscache_object *object; | |
8fb883f3 | 930 | bool wake_cookie = false; |
b5108822 DH |
931 | int ret; |
932 | ||
933 | _enter("%p,%x,", cookie, (u32) page->flags); | |
934 | ||
935 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
936 | ASSERT(PageFsCache(page)); | |
937 | ||
938 | fscache_stat(&fscache_n_stores); | |
939 | ||
ef778e7a DH |
940 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
941 | _leave(" = -ENOBUFS [invalidating]"); | |
942 | return -ENOBUFS; | |
943 | } | |
944 | ||
5f4f9f4a | 945 | op = kzalloc(sizeof(*op), GFP_NOIO | __GFP_NOMEMALLOC | __GFP_NORETRY); |
b5108822 DH |
946 | if (!op) |
947 | goto nomem; | |
948 | ||
8af7c124 TH |
949 | fscache_operation_init(&op->op, fscache_write_op, |
950 | fscache_release_write_op); | |
1362729b DH |
951 | op->op.flags = FSCACHE_OP_ASYNC | |
952 | (1 << FSCACHE_OP_WAITING) | | |
953 | (1 << FSCACHE_OP_UNUSE_COOKIE); | |
b5108822 | 954 | |
5e4c0d97 | 955 | ret = radix_tree_maybe_preload(gfp & ~__GFP_HIGHMEM); |
b5108822 DH |
956 | if (ret < 0) |
957 | goto nomem_free; | |
958 | ||
959 | ret = -ENOBUFS; | |
960 | spin_lock(&cookie->lock); | |
961 | ||
94d30ae9 DH |
962 | if (!fscache_cookie_enabled(cookie) || |
963 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
964 | goto nobufs; |
965 | object = hlist_entry(cookie->backing_objects.first, | |
966 | struct fscache_object, cookie_link); | |
967 | if (test_bit(FSCACHE_IOERROR, &object->cache->flags)) | |
968 | goto nobufs; | |
969 | ||
970 | /* add the page to the pending-storage radix tree on the backing | |
971 | * object */ | |
972 | spin_lock(&object->lock); | |
1bccf513 | 973 | spin_lock(&cookie->stores_lock); |
b5108822 DH |
974 | |
975 | _debug("store limit %llx", (unsigned long long) object->store_limit); | |
976 | ||
977 | ret = radix_tree_insert(&cookie->stores, page->index, page); | |
978 | if (ret < 0) { | |
979 | if (ret == -EEXIST) | |
980 | goto already_queued; | |
981 | _debug("insert failed %d", ret); | |
982 | goto nobufs_unlock_obj; | |
983 | } | |
984 | ||
985 | radix_tree_tag_set(&cookie->stores, page->index, | |
986 | FSCACHE_COOKIE_PENDING_TAG); | |
987 | page_cache_get(page); | |
988 | ||
989 | /* we only want one writer at a time, but we do need to queue new | |
990 | * writers after exclusive ops */ | |
991 | if (test_and_set_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags)) | |
992 | goto already_pending; | |
993 | ||
1bccf513 | 994 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
995 | spin_unlock(&object->lock); |
996 | ||
997 | op->op.debug_id = atomic_inc_return(&fscache_op_debug_id); | |
998 | op->store_limit = object->store_limit; | |
999 | ||
8fb883f3 | 1000 | __fscache_use_cookie(cookie); |
b5108822 DH |
1001 | if (fscache_submit_op(object, &op->op) < 0) |
1002 | goto submit_failed; | |
1003 | ||
1004 | spin_unlock(&cookie->lock); | |
1005 | radix_tree_preload_end(); | |
1006 | fscache_stat(&fscache_n_store_ops); | |
1007 | fscache_stat(&fscache_n_stores_ok); | |
1008 | ||
8af7c124 | 1009 | /* the work queue now carries its own ref on the object */ |
b5108822 DH |
1010 | fscache_put_operation(&op->op); |
1011 | _leave(" = 0"); | |
1012 | return 0; | |
1013 | ||
1014 | already_queued: | |
1015 | fscache_stat(&fscache_n_stores_again); | |
1016 | already_pending: | |
1bccf513 | 1017 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
1018 | spin_unlock(&object->lock); |
1019 | spin_unlock(&cookie->lock); | |
1020 | radix_tree_preload_end(); | |
1021 | kfree(op); | |
1022 | fscache_stat(&fscache_n_stores_ok); | |
1023 | _leave(" = 0"); | |
1024 | return 0; | |
1025 | ||
1026 | submit_failed: | |
1bccf513 | 1027 | spin_lock(&cookie->stores_lock); |
b5108822 | 1028 | radix_tree_delete(&cookie->stores, page->index); |
1bccf513 | 1029 | spin_unlock(&cookie->stores_lock); |
8fb883f3 | 1030 | wake_cookie = __fscache_unuse_cookie(cookie); |
b5108822 DH |
1031 | page_cache_release(page); |
1032 | ret = -ENOBUFS; | |
1033 | goto nobufs; | |
1034 | ||
1035 | nobufs_unlock_obj: | |
1147d0f9 | 1036 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
1037 | spin_unlock(&object->lock); |
1038 | nobufs: | |
1039 | spin_unlock(&cookie->lock); | |
1040 | radix_tree_preload_end(); | |
1041 | kfree(op); | |
8fb883f3 DH |
1042 | if (wake_cookie) |
1043 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
1044 | fscache_stat(&fscache_n_stores_nobufs); |
1045 | _leave(" = -ENOBUFS"); | |
1046 | return -ENOBUFS; | |
1047 | ||
1048 | nomem_free: | |
1049 | kfree(op); | |
1050 | nomem: | |
1051 | fscache_stat(&fscache_n_stores_oom); | |
1052 | _leave(" = -ENOMEM"); | |
1053 | return -ENOMEM; | |
1054 | } | |
1055 | EXPORT_SYMBOL(__fscache_write_page); | |
1056 | ||
1057 | /* | |
1058 | * remove a page from the cache | |
1059 | */ | |
1060 | void __fscache_uncache_page(struct fscache_cookie *cookie, struct page *page) | |
1061 | { | |
1062 | struct fscache_object *object; | |
1063 | ||
1064 | _enter(",%p", page); | |
1065 | ||
1066 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
1067 | ASSERTCMP(page, !=, NULL); | |
1068 | ||
1069 | fscache_stat(&fscache_n_uncaches); | |
1070 | ||
1071 | /* cache withdrawal may beat us to it */ | |
1072 | if (!PageFsCache(page)) | |
1073 | goto done; | |
1074 | ||
1075 | /* get the object */ | |
1076 | spin_lock(&cookie->lock); | |
1077 | ||
1078 | if (hlist_empty(&cookie->backing_objects)) { | |
1079 | ClearPageFsCache(page); | |
1080 | goto done_unlock; | |
1081 | } | |
1082 | ||
1083 | object = hlist_entry(cookie->backing_objects.first, | |
1084 | struct fscache_object, cookie_link); | |
1085 | ||
1086 | /* there might now be stuff on disk we could read */ | |
1087 | clear_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); | |
1088 | ||
1089 | /* only invoke the cache backend if we managed to mark the page | |
1090 | * uncached here; this deals with synchronisation vs withdrawal */ | |
1091 | if (TestClearPageFsCache(page) && | |
1092 | object->cache->ops->uncache_page) { | |
1093 | /* the cache backend releases the cookie lock */ | |
52bd75fd | 1094 | fscache_stat(&fscache_n_cop_uncache_page); |
b5108822 | 1095 | object->cache->ops->uncache_page(object, page); |
52bd75fd | 1096 | fscache_stat_d(&fscache_n_cop_uncache_page); |
b5108822 DH |
1097 | goto done; |
1098 | } | |
1099 | ||
1100 | done_unlock: | |
1101 | spin_unlock(&cookie->lock); | |
1102 | done: | |
1103 | _leave(""); | |
1104 | } | |
1105 | EXPORT_SYMBOL(__fscache_uncache_page); | |
1106 | ||
c4d6d8db DH |
1107 | /** |
1108 | * fscache_mark_page_cached - Mark a page as being cached | |
1109 | * @op: The retrieval op pages are being marked for | |
1110 | * @page: The page to be marked | |
1111 | * | |
1112 | * Mark a netfs page as being cached. After this is called, the netfs | |
1113 | * must call fscache_uncache_page() to remove the mark. | |
1114 | */ | |
1115 | void fscache_mark_page_cached(struct fscache_retrieval *op, struct page *page) | |
1116 | { | |
1117 | struct fscache_cookie *cookie = op->op.object->cookie; | |
1118 | ||
1119 | #ifdef CONFIG_FSCACHE_STATS | |
1120 | atomic_inc(&fscache_n_marks); | |
1121 | #endif | |
1122 | ||
1123 | _debug("- mark %p{%lx}", page, page->index); | |
1124 | if (TestSetPageFsCache(page)) { | |
1125 | static bool once_only; | |
1126 | if (!once_only) { | |
1127 | once_only = true; | |
36dfd116 FF |
1128 | pr_warn("Cookie type %s marked page %lx multiple times\n", |
1129 | cookie->def->name, page->index); | |
c4d6d8db DH |
1130 | } |
1131 | } | |
1132 | ||
1133 | if (cookie->def->mark_page_cached) | |
1134 | cookie->def->mark_page_cached(cookie->netfs_data, | |
1135 | op->mapping, page); | |
1136 | } | |
1137 | EXPORT_SYMBOL(fscache_mark_page_cached); | |
1138 | ||
b5108822 DH |
1139 | /** |
1140 | * fscache_mark_pages_cached - Mark pages as being cached | |
1141 | * @op: The retrieval op pages are being marked for | |
1142 | * @pagevec: The pages to be marked | |
1143 | * | |
1144 | * Mark a bunch of netfs pages as being cached. After this is called, | |
1145 | * the netfs must call fscache_uncache_page() to remove the mark. | |
1146 | */ | |
1147 | void fscache_mark_pages_cached(struct fscache_retrieval *op, | |
1148 | struct pagevec *pagevec) | |
1149 | { | |
b5108822 DH |
1150 | unsigned long loop; |
1151 | ||
c4d6d8db DH |
1152 | for (loop = 0; loop < pagevec->nr; loop++) |
1153 | fscache_mark_page_cached(op, pagevec->pages[loop]); | |
b5108822 | 1154 | |
b5108822 DH |
1155 | pagevec_reinit(pagevec); |
1156 | } | |
1157 | EXPORT_SYMBOL(fscache_mark_pages_cached); | |
c902ce1b DH |
1158 | |
1159 | /* | |
1160 | * Uncache all the pages in an inode that are marked PG_fscache, assuming them | |
1161 | * to be associated with the given cookie. | |
1162 | */ | |
1163 | void __fscache_uncache_all_inode_pages(struct fscache_cookie *cookie, | |
1164 | struct inode *inode) | |
1165 | { | |
1166 | struct address_space *mapping = inode->i_mapping; | |
1167 | struct pagevec pvec; | |
1168 | pgoff_t next; | |
1169 | int i; | |
1170 | ||
1171 | _enter("%p,%p", cookie, inode); | |
1172 | ||
1173 | if (!mapping || mapping->nrpages == 0) { | |
1174 | _leave(" [no pages]"); | |
1175 | return; | |
1176 | } | |
1177 | ||
1178 | pagevec_init(&pvec, 0); | |
1179 | next = 0; | |
b307d465 JB |
1180 | do { |
1181 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) | |
1182 | break; | |
c902ce1b DH |
1183 | for (i = 0; i < pagevec_count(&pvec); i++) { |
1184 | struct page *page = pvec.pages[i]; | |
b307d465 | 1185 | next = page->index; |
c902ce1b DH |
1186 | if (PageFsCache(page)) { |
1187 | __fscache_wait_on_page_write(cookie, page); | |
1188 | __fscache_uncache_page(cookie, page); | |
1189 | } | |
1190 | } | |
1191 | pagevec_release(&pvec); | |
1192 | cond_resched(); | |
b307d465 | 1193 | } while (++next); |
c902ce1b DH |
1194 | |
1195 | _leave(""); | |
1196 | } | |
1197 | EXPORT_SYMBOL(__fscache_uncache_all_inode_pages); |