Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
b5108822 DH |
2 | /* Cache page management and data I/O routines |
3 | * | |
4 | * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved. | |
5 | * Written by David Howells (dhowells@redhat.com) | |
b5108822 DH |
6 | */ |
7 | ||
8 | #define FSCACHE_DEBUG_LEVEL PAGE | |
9 | #include <linux/module.h> | |
10 | #include <linux/fscache-cache.h> | |
11 | #include <linux/buffer_head.h> | |
12 | #include <linux/pagevec.h> | |
5a0e3ad6 | 13 | #include <linux/slab.h> |
b5108822 DH |
14 | #include "internal.h" |
15 | ||
16 | /* | |
17 | * check to see if a page is being written to the cache | |
18 | */ | |
19 | bool __fscache_check_page_write(struct fscache_cookie *cookie, struct page *page) | |
20 | { | |
21 | void *val; | |
22 | ||
23 | rcu_read_lock(); | |
24 | val = radix_tree_lookup(&cookie->stores, page->index); | |
25 | rcu_read_unlock(); | |
08c2e3d0 | 26 | trace_fscache_check_page(cookie, page, val, 0); |
b5108822 DH |
27 | |
28 | return val != NULL; | |
29 | } | |
30 | EXPORT_SYMBOL(__fscache_check_page_write); | |
31 | ||
32 | /* | |
33 | * wait for a page to finish being written to the cache | |
34 | */ | |
35 | void __fscache_wait_on_page_write(struct fscache_cookie *cookie, struct page *page) | |
36 | { | |
37 | wait_queue_head_t *wq = bit_waitqueue(&cookie->flags, 0); | |
38 | ||
08c2e3d0 DH |
39 | trace_fscache_page(cookie, page, fscache_page_write_wait); |
40 | ||
b5108822 DH |
41 | wait_event(*wq, !__fscache_check_page_write(cookie, page)); |
42 | } | |
43 | EXPORT_SYMBOL(__fscache_wait_on_page_write); | |
44 | ||
9776de96 MT |
45 | /* |
46 | * wait for a page to finish being written to the cache. Put a timeout here | |
47 | * since we might be called recursively via parent fs. | |
48 | */ | |
49 | static | |
50 | bool release_page_wait_timeout(struct fscache_cookie *cookie, struct page *page) | |
51 | { | |
52 | wait_queue_head_t *wq = bit_waitqueue(&cookie->flags, 0); | |
53 | ||
54 | return wait_event_timeout(*wq, !__fscache_check_page_write(cookie, page), | |
55 | HZ); | |
56 | } | |
57 | ||
201a1542 DH |
58 | /* |
59 | * decide whether a page can be released, possibly by cancelling a store to it | |
d0164adc | 60 | * - we're allowed to sleep if __GFP_DIRECT_RECLAIM is flagged |
201a1542 DH |
61 | */ |
62 | bool __fscache_maybe_release_page(struct fscache_cookie *cookie, | |
63 | struct page *page, | |
64 | gfp_t gfp) | |
65 | { | |
66 | struct page *xpage; | |
67 | void *val; | |
68 | ||
69 | _enter("%p,%p,%x", cookie, page, gfp); | |
70 | ||
08c2e3d0 DH |
71 | trace_fscache_page(cookie, page, fscache_page_maybe_release); |
72 | ||
8c209ce7 | 73 | try_again: |
201a1542 DH |
74 | rcu_read_lock(); |
75 | val = radix_tree_lookup(&cookie->stores, page->index); | |
76 | if (!val) { | |
77 | rcu_read_unlock(); | |
78 | fscache_stat(&fscache_n_store_vmscan_not_storing); | |
79 | __fscache_uncache_page(cookie, page); | |
80 | return true; | |
81 | } | |
82 | ||
83 | /* see if the page is actually undergoing storage - if so we can't get | |
84 | * rid of it till the cache has finished with it */ | |
85 | if (radix_tree_tag_get(&cookie->stores, page->index, | |
86 | FSCACHE_COOKIE_STORING_TAG)) { | |
87 | rcu_read_unlock(); | |
88 | goto page_busy; | |
89 | } | |
90 | ||
91 | /* the page is pending storage, so we attempt to cancel the store and | |
92 | * discard the store request so that the page can be reclaimed */ | |
93 | spin_lock(&cookie->stores_lock); | |
94 | rcu_read_unlock(); | |
95 | ||
96 | if (radix_tree_tag_get(&cookie->stores, page->index, | |
97 | FSCACHE_COOKIE_STORING_TAG)) { | |
98 | /* the page started to undergo storage whilst we were looking, | |
99 | * so now we can only wait or return */ | |
100 | spin_unlock(&cookie->stores_lock); | |
101 | goto page_busy; | |
102 | } | |
103 | ||
104 | xpage = radix_tree_delete(&cookie->stores, page->index); | |
08c2e3d0 | 105 | trace_fscache_page(cookie, page, fscache_page_radix_delete); |
201a1542 DH |
106 | spin_unlock(&cookie->stores_lock); |
107 | ||
108 | if (xpage) { | |
109 | fscache_stat(&fscache_n_store_vmscan_cancelled); | |
110 | fscache_stat(&fscache_n_store_radix_deletes); | |
111 | ASSERTCMP(xpage, ==, page); | |
112 | } else { | |
113 | fscache_stat(&fscache_n_store_vmscan_gone); | |
114 | } | |
115 | ||
116 | wake_up_bit(&cookie->flags, 0); | |
08c2e3d0 | 117 | trace_fscache_wake_cookie(cookie); |
201a1542 | 118 | if (xpage) |
09cbfeaf | 119 | put_page(xpage); |
201a1542 DH |
120 | __fscache_uncache_page(cookie, page); |
121 | return true; | |
122 | ||
123 | page_busy: | |
8c209ce7 DH |
124 | /* We will wait here if we're allowed to, but that could deadlock the |
125 | * allocator as the work threads writing to the cache may all end up | |
126 | * sleeping on memory allocation, so we may need to impose a timeout | |
127 | * too. */ | |
d0164adc | 128 | if (!(gfp & __GFP_DIRECT_RECLAIM) || !(gfp & __GFP_FS)) { |
8c209ce7 DH |
129 | fscache_stat(&fscache_n_store_vmscan_busy); |
130 | return false; | |
131 | } | |
132 | ||
133 | fscache_stat(&fscache_n_store_vmscan_wait); | |
9776de96 MT |
134 | if (!release_page_wait_timeout(cookie, page)) |
135 | _debug("fscache writeout timeout page: %p{%lx}", | |
136 | page, page->index); | |
137 | ||
d0164adc | 138 | gfp &= ~__GFP_DIRECT_RECLAIM; |
8c209ce7 | 139 | goto try_again; |
201a1542 DH |
140 | } |
141 | EXPORT_SYMBOL(__fscache_maybe_release_page); | |
142 | ||
b5108822 DH |
143 | /* |
144 | * note that a page has finished being written to the cache | |
145 | */ | |
1bccf513 DH |
146 | static void fscache_end_page_write(struct fscache_object *object, |
147 | struct page *page) | |
b5108822 | 148 | { |
1bccf513 | 149 | struct fscache_cookie *cookie; |
08c2e3d0 | 150 | struct page *xpage = NULL, *val; |
b5108822 | 151 | |
1bccf513 DH |
152 | spin_lock(&object->lock); |
153 | cookie = object->cookie; | |
154 | if (cookie) { | |
155 | /* delete the page from the tree if it is now no longer | |
156 | * pending */ | |
157 | spin_lock(&cookie->stores_lock); | |
201a1542 DH |
158 | radix_tree_tag_clear(&cookie->stores, page->index, |
159 | FSCACHE_COOKIE_STORING_TAG); | |
08c2e3d0 | 160 | trace_fscache_page(cookie, page, fscache_page_radix_clear_store); |
285e728b DH |
161 | if (!radix_tree_tag_get(&cookie->stores, page->index, |
162 | FSCACHE_COOKIE_PENDING_TAG)) { | |
163 | fscache_stat(&fscache_n_store_radix_deletes); | |
164 | xpage = radix_tree_delete(&cookie->stores, page->index); | |
08c2e3d0 DH |
165 | trace_fscache_page(cookie, page, fscache_page_radix_delete); |
166 | trace_fscache_page(cookie, page, fscache_page_write_end); | |
167 | ||
168 | val = radix_tree_lookup(&cookie->stores, page->index); | |
169 | trace_fscache_check_page(cookie, page, val, 1); | |
170 | } else { | |
171 | trace_fscache_page(cookie, page, fscache_page_write_end_pend); | |
285e728b | 172 | } |
1bccf513 DH |
173 | spin_unlock(&cookie->stores_lock); |
174 | wake_up_bit(&cookie->flags, 0); | |
08c2e3d0 DH |
175 | trace_fscache_wake_cookie(cookie); |
176 | } else { | |
177 | trace_fscache_page(cookie, page, fscache_page_write_end_noc); | |
1bccf513 DH |
178 | } |
179 | spin_unlock(&object->lock); | |
180 | if (xpage) | |
09cbfeaf | 181 | put_page(xpage); |
b5108822 DH |
182 | } |
183 | ||
184 | /* | |
185 | * actually apply the changed attributes to a cache object | |
186 | */ | |
187 | static void fscache_attr_changed_op(struct fscache_operation *op) | |
188 | { | |
189 | struct fscache_object *object = op->object; | |
440f0aff | 190 | int ret; |
b5108822 DH |
191 | |
192 | _enter("{OBJ%x OP%x}", object->debug_id, op->debug_id); | |
193 | ||
194 | fscache_stat(&fscache_n_attr_changed_calls); | |
195 | ||
8fb883f3 | 196 | if (fscache_object_is_active(object)) { |
52bd75fd | 197 | fscache_stat(&fscache_n_cop_attr_changed); |
440f0aff | 198 | ret = object->cache->ops->attr_changed(object); |
52bd75fd | 199 | fscache_stat_d(&fscache_n_cop_attr_changed); |
440f0aff DH |
200 | if (ret < 0) |
201 | fscache_abort_object(object); | |
b27ddd46 DH |
202 | fscache_op_complete(op, ret < 0); |
203 | } else { | |
204 | fscache_op_complete(op, true); | |
440f0aff | 205 | } |
b5108822 DH |
206 | |
207 | _leave(""); | |
208 | } | |
209 | ||
210 | /* | |
211 | * notification that the attributes on an object have changed | |
212 | */ | |
213 | int __fscache_attr_changed(struct fscache_cookie *cookie) | |
214 | { | |
215 | struct fscache_operation *op; | |
216 | struct fscache_object *object; | |
3e1199dc | 217 | bool wake_cookie = false; |
b5108822 DH |
218 | |
219 | _enter("%p", cookie); | |
220 | ||
221 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
222 | ||
223 | fscache_stat(&fscache_n_attr_changed); | |
224 | ||
225 | op = kzalloc(sizeof(*op), GFP_KERNEL); | |
226 | if (!op) { | |
227 | fscache_stat(&fscache_n_attr_changed_nomem); | |
228 | _leave(" = -ENOMEM"); | |
229 | return -ENOMEM; | |
230 | } | |
231 | ||
08c2e3d0 DH |
232 | fscache_operation_init(cookie, op, fscache_attr_changed_op, NULL, NULL); |
233 | trace_fscache_page_op(cookie, NULL, op, fscache_page_op_attr_changed); | |
8fb883f3 DH |
234 | op->flags = FSCACHE_OP_ASYNC | |
235 | (1 << FSCACHE_OP_EXCLUSIVE) | | |
236 | (1 << FSCACHE_OP_UNUSE_COOKIE); | |
b5108822 DH |
237 | |
238 | spin_lock(&cookie->lock); | |
239 | ||
94d30ae9 DH |
240 | if (!fscache_cookie_enabled(cookie) || |
241 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
242 | goto nobufs; |
243 | object = hlist_entry(cookie->backing_objects.first, | |
244 | struct fscache_object, cookie_link); | |
245 | ||
8fb883f3 | 246 | __fscache_use_cookie(cookie); |
b5108822 | 247 | if (fscache_submit_exclusive_op(object, op) < 0) |
3e1199dc | 248 | goto nobufs_dec; |
b5108822 DH |
249 | spin_unlock(&cookie->lock); |
250 | fscache_stat(&fscache_n_attr_changed_ok); | |
251 | fscache_put_operation(op); | |
252 | _leave(" = 0"); | |
253 | return 0; | |
254 | ||
3e1199dc | 255 | nobufs_dec: |
8fb883f3 | 256 | wake_cookie = __fscache_unuse_cookie(cookie); |
3e1199dc | 257 | nobufs: |
b5108822 | 258 | spin_unlock(&cookie->lock); |
a39caadf | 259 | fscache_put_operation(op); |
8fb883f3 DH |
260 | if (wake_cookie) |
261 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
262 | fscache_stat(&fscache_n_attr_changed_nobufs); |
263 | _leave(" = %d", -ENOBUFS); | |
264 | return -ENOBUFS; | |
265 | } | |
266 | EXPORT_SYMBOL(__fscache_attr_changed); | |
267 | ||
d3b97ca4 DH |
268 | /* |
269 | * Handle cancellation of a pending retrieval op | |
270 | */ | |
271 | static void fscache_do_cancel_retrieval(struct fscache_operation *_op) | |
272 | { | |
273 | struct fscache_retrieval *op = | |
274 | container_of(_op, struct fscache_retrieval, op); | |
275 | ||
276 | atomic_set(&op->n_pages, 0); | |
277 | } | |
278 | ||
b5108822 DH |
279 | /* |
280 | * release a retrieval op reference | |
281 | */ | |
282 | static void fscache_release_retrieval_op(struct fscache_operation *_op) | |
283 | { | |
284 | struct fscache_retrieval *op = | |
285 | container_of(_op, struct fscache_retrieval, op); | |
286 | ||
287 | _enter("{OP%x}", op->op.debug_id); | |
288 | ||
4a47132f DH |
289 | ASSERTIFCMP(op->op.state != FSCACHE_OP_ST_INITIALISED, |
290 | atomic_read(&op->n_pages), ==, 0); | |
9f10523f | 291 | |
b5108822 DH |
292 | fscache_hist(fscache_retrieval_histogram, op->start_time); |
293 | if (op->context) | |
4a47132f | 294 | fscache_put_context(op->cookie, op->context); |
b5108822 DH |
295 | |
296 | _leave(""); | |
297 | } | |
298 | ||
299 | /* | |
300 | * allocate a retrieval op | |
301 | */ | |
302 | static struct fscache_retrieval *fscache_alloc_retrieval( | |
1362729b | 303 | struct fscache_cookie *cookie, |
b5108822 DH |
304 | struct address_space *mapping, |
305 | fscache_rw_complete_t end_io_func, | |
306 | void *context) | |
307 | { | |
308 | struct fscache_retrieval *op; | |
309 | ||
310 | /* allocate a retrieval operation and attempt to submit it */ | |
311 | op = kzalloc(sizeof(*op), GFP_NOIO); | |
312 | if (!op) { | |
313 | fscache_stat(&fscache_n_retrievals_nomem); | |
314 | return NULL; | |
315 | } | |
316 | ||
08c2e3d0 | 317 | fscache_operation_init(cookie, &op->op, NULL, |
d3b97ca4 DH |
318 | fscache_do_cancel_retrieval, |
319 | fscache_release_retrieval_op); | |
1362729b DH |
320 | op->op.flags = FSCACHE_OP_MYTHREAD | |
321 | (1UL << FSCACHE_OP_WAITING) | | |
322 | (1UL << FSCACHE_OP_UNUSE_COOKIE); | |
4a47132f | 323 | op->cookie = cookie; |
b5108822 DH |
324 | op->mapping = mapping; |
325 | op->end_io_func = end_io_func; | |
326 | op->context = context; | |
327 | op->start_time = jiffies; | |
b5108822 | 328 | INIT_LIST_HEAD(&op->to_do); |
4a47132f DH |
329 | |
330 | /* Pin the netfs read context in case we need to do the actual netfs | |
331 | * read because we've encountered a cache read failure. | |
332 | */ | |
333 | if (context) | |
334 | fscache_get_context(op->cookie, context); | |
b5108822 DH |
335 | return op; |
336 | } | |
337 | ||
338 | /* | |
339 | * wait for a deferred lookup to complete | |
340 | */ | |
da9803bc | 341 | int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie) |
b5108822 DH |
342 | { |
343 | unsigned long jif; | |
344 | ||
345 | _enter(""); | |
346 | ||
347 | if (!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) { | |
348 | _leave(" = 0 [imm]"); | |
349 | return 0; | |
350 | } | |
351 | ||
352 | fscache_stat(&fscache_n_retrievals_wait); | |
353 | ||
354 | jif = jiffies; | |
355 | if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP, | |
b5108822 DH |
356 | TASK_INTERRUPTIBLE) != 0) { |
357 | fscache_stat(&fscache_n_retrievals_intr); | |
358 | _leave(" = -ERESTARTSYS"); | |
359 | return -ERESTARTSYS; | |
360 | } | |
361 | ||
362 | ASSERT(!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)); | |
363 | ||
364 | smp_rmb(); | |
365 | fscache_hist(fscache_retrieval_delay_histogram, jif); | |
366 | _leave(" = 0 [dly]"); | |
367 | return 0; | |
368 | } | |
369 | ||
60d543ca DH |
370 | /* |
371 | * wait for an object to become active (or dead) | |
372 | */ | |
da9803bc DH |
373 | int fscache_wait_for_operation_activation(struct fscache_object *object, |
374 | struct fscache_operation *op, | |
375 | atomic_t *stat_op_waits, | |
d3b97ca4 | 376 | atomic_t *stat_object_dead) |
60d543ca DH |
377 | { |
378 | int ret; | |
379 | ||
da9803bc | 380 | if (!test_bit(FSCACHE_OP_WAITING, &op->flags)) |
60d543ca DH |
381 | goto check_if_dead; |
382 | ||
383 | _debug(">>> WT"); | |
da9803bc DH |
384 | if (stat_op_waits) |
385 | fscache_stat(stat_op_waits); | |
386 | if (wait_on_bit(&op->flags, FSCACHE_OP_WAITING, | |
9c04caa8 | 387 | TASK_INTERRUPTIBLE) != 0) { |
08c2e3d0 | 388 | trace_fscache_op(object->cookie, op, fscache_op_signal); |
d3b97ca4 | 389 | ret = fscache_cancel_op(op, false); |
60d543ca DH |
390 | if (ret == 0) |
391 | return -ERESTARTSYS; | |
392 | ||
393 | /* it's been removed from the pending queue by another party, | |
394 | * so we should get to run shortly */ | |
da9803bc | 395 | wait_on_bit(&op->flags, FSCACHE_OP_WAITING, |
74316201 | 396 | TASK_UNINTERRUPTIBLE); |
60d543ca DH |
397 | } |
398 | _debug("<<< GO"); | |
399 | ||
400 | check_if_dead: | |
da9803bc DH |
401 | if (op->state == FSCACHE_OP_ST_CANCELLED) { |
402 | if (stat_object_dead) | |
403 | fscache_stat(stat_object_dead); | |
9f10523f DH |
404 | _leave(" = -ENOBUFS [cancelled]"); |
405 | return -ENOBUFS; | |
406 | } | |
87021526 DH |
407 | if (unlikely(fscache_object_is_dying(object) || |
408 | fscache_cache_is_broken(object))) { | |
409 | enum fscache_operation_state state = op->state; | |
08c2e3d0 | 410 | trace_fscache_op(object->cookie, op, fscache_op_signal); |
d3b97ca4 | 411 | fscache_cancel_op(op, true); |
da9803bc DH |
412 | if (stat_object_dead) |
413 | fscache_stat(stat_object_dead); | |
87021526 | 414 | _leave(" = -ENOBUFS [obj dead %d]", state); |
60d543ca DH |
415 | return -ENOBUFS; |
416 | } | |
417 | return 0; | |
418 | } | |
419 | ||
b5108822 DH |
420 | /* |
421 | * read a page from the cache or allocate a block in which to store it | |
422 | * - we return: | |
423 | * -ENOMEM - out of memory, nothing done | |
424 | * -ERESTARTSYS - interrupted | |
425 | * -ENOBUFS - no backing object available in which to cache the block | |
426 | * -ENODATA - no data available in the backing object for this block | |
427 | * 0 - dispatched a read - it'll call end_io_func() when finished | |
428 | */ | |
429 | int __fscache_read_or_alloc_page(struct fscache_cookie *cookie, | |
430 | struct page *page, | |
431 | fscache_rw_complete_t end_io_func, | |
432 | void *context, | |
433 | gfp_t gfp) | |
434 | { | |
435 | struct fscache_retrieval *op; | |
436 | struct fscache_object *object; | |
8fb883f3 | 437 | bool wake_cookie = false; |
b5108822 DH |
438 | int ret; |
439 | ||
440 | _enter("%p,%p,,,", cookie, page); | |
441 | ||
442 | fscache_stat(&fscache_n_retrievals); | |
443 | ||
444 | if (hlist_empty(&cookie->backing_objects)) | |
445 | goto nobufs; | |
446 | ||
ef778e7a DH |
447 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
448 | _leave(" = -ENOBUFS [invalidating]"); | |
449 | return -ENOBUFS; | |
450 | } | |
451 | ||
b5108822 DH |
452 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); |
453 | ASSERTCMP(page, !=, NULL); | |
454 | ||
455 | if (fscache_wait_for_deferred_lookup(cookie) < 0) | |
456 | return -ERESTARTSYS; | |
457 | ||
1362729b | 458 | op = fscache_alloc_retrieval(cookie, page->mapping, |
94d30ae9 | 459 | end_io_func, context); |
b5108822 DH |
460 | if (!op) { |
461 | _leave(" = -ENOMEM"); | |
462 | return -ENOMEM; | |
463 | } | |
1bb4b7f9 | 464 | atomic_set(&op->n_pages, 1); |
08c2e3d0 | 465 | trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_retr_one); |
b5108822 DH |
466 | |
467 | spin_lock(&cookie->lock); | |
468 | ||
94d30ae9 DH |
469 | if (!fscache_cookie_enabled(cookie) || |
470 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
471 | goto nobufs_unlock; |
472 | object = hlist_entry(cookie->backing_objects.first, | |
473 | struct fscache_object, cookie_link); | |
474 | ||
caaef690 | 475 | ASSERT(test_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)); |
b5108822 | 476 | |
8fb883f3 | 477 | __fscache_use_cookie(cookie); |
4fbf4291 | 478 | atomic_inc(&object->n_reads); |
9f10523f | 479 | __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags); |
4fbf4291 | 480 | |
b5108822 | 481 | if (fscache_submit_op(object, &op->op) < 0) |
9f10523f | 482 | goto nobufs_unlock_dec; |
b5108822 DH |
483 | spin_unlock(&cookie->lock); |
484 | ||
485 | fscache_stat(&fscache_n_retrieval_ops); | |
486 | ||
b5108822 DH |
487 | /* we wait for the operation to become active, and then process it |
488 | * *here*, in this thread, and not in the thread pool */ | |
da9803bc DH |
489 | ret = fscache_wait_for_operation_activation( |
490 | object, &op->op, | |
60d543ca | 491 | __fscache_stat(&fscache_n_retrieval_op_waits), |
d3b97ca4 | 492 | __fscache_stat(&fscache_n_retrievals_object_dead)); |
60d543ca DH |
493 | if (ret < 0) |
494 | goto error; | |
b5108822 DH |
495 | |
496 | /* ask the cache to honour the operation */ | |
497 | if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) { | |
52bd75fd | 498 | fscache_stat(&fscache_n_cop_allocate_page); |
b5108822 | 499 | ret = object->cache->ops->allocate_page(op, page, gfp); |
52bd75fd | 500 | fscache_stat_d(&fscache_n_cop_allocate_page); |
b5108822 DH |
501 | if (ret == 0) |
502 | ret = -ENODATA; | |
503 | } else { | |
52bd75fd | 504 | fscache_stat(&fscache_n_cop_read_or_alloc_page); |
b5108822 | 505 | ret = object->cache->ops->read_or_alloc_page(op, page, gfp); |
52bd75fd | 506 | fscache_stat_d(&fscache_n_cop_read_or_alloc_page); |
b5108822 DH |
507 | } |
508 | ||
5753c441 | 509 | error: |
b5108822 DH |
510 | if (ret == -ENOMEM) |
511 | fscache_stat(&fscache_n_retrievals_nomem); | |
512 | else if (ret == -ERESTARTSYS) | |
513 | fscache_stat(&fscache_n_retrievals_intr); | |
514 | else if (ret == -ENODATA) | |
515 | fscache_stat(&fscache_n_retrievals_nodata); | |
516 | else if (ret < 0) | |
517 | fscache_stat(&fscache_n_retrievals_nobufs); | |
518 | else | |
519 | fscache_stat(&fscache_n_retrievals_ok); | |
520 | ||
521 | fscache_put_retrieval(op); | |
522 | _leave(" = %d", ret); | |
523 | return ret; | |
524 | ||
9f10523f DH |
525 | nobufs_unlock_dec: |
526 | atomic_dec(&object->n_reads); | |
8fb883f3 | 527 | wake_cookie = __fscache_unuse_cookie(cookie); |
b5108822 DH |
528 | nobufs_unlock: |
529 | spin_unlock(&cookie->lock); | |
8fb883f3 DH |
530 | if (wake_cookie) |
531 | __fscache_wake_unused_cookie(cookie); | |
a39caadf | 532 | fscache_put_retrieval(op); |
b5108822 DH |
533 | nobufs: |
534 | fscache_stat(&fscache_n_retrievals_nobufs); | |
535 | _leave(" = -ENOBUFS"); | |
536 | return -ENOBUFS; | |
537 | } | |
538 | EXPORT_SYMBOL(__fscache_read_or_alloc_page); | |
539 | ||
540 | /* | |
541 | * read a list of page from the cache or allocate a block in which to store | |
542 | * them | |
543 | * - we return: | |
544 | * -ENOMEM - out of memory, some pages may be being read | |
545 | * -ERESTARTSYS - interrupted, some pages may be being read | |
546 | * -ENOBUFS - no backing object or space available in which to cache any | |
547 | * pages not being read | |
548 | * -ENODATA - no data available in the backing object for some or all of | |
549 | * the pages | |
550 | * 0 - dispatched a read on all pages | |
551 | * | |
552 | * end_io_func() will be called for each page read from the cache as it is | |
553 | * finishes being read | |
554 | * | |
555 | * any pages for which a read is dispatched will be removed from pages and | |
556 | * nr_pages | |
557 | */ | |
558 | int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie, | |
559 | struct address_space *mapping, | |
560 | struct list_head *pages, | |
561 | unsigned *nr_pages, | |
562 | fscache_rw_complete_t end_io_func, | |
563 | void *context, | |
564 | gfp_t gfp) | |
565 | { | |
b5108822 DH |
566 | struct fscache_retrieval *op; |
567 | struct fscache_object *object; | |
8fb883f3 | 568 | bool wake_cookie = false; |
b5108822 DH |
569 | int ret; |
570 | ||
571 | _enter("%p,,%d,,,", cookie, *nr_pages); | |
572 | ||
573 | fscache_stat(&fscache_n_retrievals); | |
574 | ||
575 | if (hlist_empty(&cookie->backing_objects)) | |
576 | goto nobufs; | |
577 | ||
ef778e7a DH |
578 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
579 | _leave(" = -ENOBUFS [invalidating]"); | |
580 | return -ENOBUFS; | |
581 | } | |
582 | ||
b5108822 DH |
583 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); |
584 | ASSERTCMP(*nr_pages, >, 0); | |
585 | ASSERT(!list_empty(pages)); | |
586 | ||
587 | if (fscache_wait_for_deferred_lookup(cookie) < 0) | |
588 | return -ERESTARTSYS; | |
589 | ||
1362729b | 590 | op = fscache_alloc_retrieval(cookie, mapping, end_io_func, context); |
b5108822 DH |
591 | if (!op) |
592 | return -ENOMEM; | |
1bb4b7f9 | 593 | atomic_set(&op->n_pages, *nr_pages); |
08c2e3d0 | 594 | trace_fscache_page_op(cookie, NULL, &op->op, fscache_page_op_retr_multi); |
b5108822 DH |
595 | |
596 | spin_lock(&cookie->lock); | |
597 | ||
94d30ae9 DH |
598 | if (!fscache_cookie_enabled(cookie) || |
599 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
600 | goto nobufs_unlock; |
601 | object = hlist_entry(cookie->backing_objects.first, | |
602 | struct fscache_object, cookie_link); | |
603 | ||
8fb883f3 | 604 | __fscache_use_cookie(cookie); |
4fbf4291 | 605 | atomic_inc(&object->n_reads); |
9f10523f | 606 | __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags); |
4fbf4291 | 607 | |
b5108822 | 608 | if (fscache_submit_op(object, &op->op) < 0) |
9f10523f | 609 | goto nobufs_unlock_dec; |
b5108822 DH |
610 | spin_unlock(&cookie->lock); |
611 | ||
612 | fscache_stat(&fscache_n_retrieval_ops); | |
613 | ||
b5108822 DH |
614 | /* we wait for the operation to become active, and then process it |
615 | * *here*, in this thread, and not in the thread pool */ | |
da9803bc DH |
616 | ret = fscache_wait_for_operation_activation( |
617 | object, &op->op, | |
60d543ca | 618 | __fscache_stat(&fscache_n_retrieval_op_waits), |
d3b97ca4 | 619 | __fscache_stat(&fscache_n_retrievals_object_dead)); |
60d543ca DH |
620 | if (ret < 0) |
621 | goto error; | |
b5108822 DH |
622 | |
623 | /* ask the cache to honour the operation */ | |
52bd75fd DH |
624 | if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) { |
625 | fscache_stat(&fscache_n_cop_allocate_pages); | |
626 | ret = object->cache->ops->allocate_pages( | |
627 | op, pages, nr_pages, gfp); | |
628 | fscache_stat_d(&fscache_n_cop_allocate_pages); | |
629 | } else { | |
630 | fscache_stat(&fscache_n_cop_read_or_alloc_pages); | |
631 | ret = object->cache->ops->read_or_alloc_pages( | |
632 | op, pages, nr_pages, gfp); | |
633 | fscache_stat_d(&fscache_n_cop_read_or_alloc_pages); | |
634 | } | |
b5108822 | 635 | |
5753c441 | 636 | error: |
b5108822 DH |
637 | if (ret == -ENOMEM) |
638 | fscache_stat(&fscache_n_retrievals_nomem); | |
639 | else if (ret == -ERESTARTSYS) | |
640 | fscache_stat(&fscache_n_retrievals_intr); | |
641 | else if (ret == -ENODATA) | |
642 | fscache_stat(&fscache_n_retrievals_nodata); | |
643 | else if (ret < 0) | |
644 | fscache_stat(&fscache_n_retrievals_nobufs); | |
645 | else | |
646 | fscache_stat(&fscache_n_retrievals_ok); | |
647 | ||
648 | fscache_put_retrieval(op); | |
649 | _leave(" = %d", ret); | |
650 | return ret; | |
651 | ||
9f10523f DH |
652 | nobufs_unlock_dec: |
653 | atomic_dec(&object->n_reads); | |
8fb883f3 | 654 | wake_cookie = __fscache_unuse_cookie(cookie); |
b5108822 DH |
655 | nobufs_unlock: |
656 | spin_unlock(&cookie->lock); | |
a39caadf | 657 | fscache_put_retrieval(op); |
8fb883f3 DH |
658 | if (wake_cookie) |
659 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
660 | nobufs: |
661 | fscache_stat(&fscache_n_retrievals_nobufs); | |
662 | _leave(" = -ENOBUFS"); | |
663 | return -ENOBUFS; | |
664 | } | |
665 | EXPORT_SYMBOL(__fscache_read_or_alloc_pages); | |
666 | ||
667 | /* | |
668 | * allocate a block in the cache on which to store a page | |
669 | * - we return: | |
670 | * -ENOMEM - out of memory, nothing done | |
671 | * -ERESTARTSYS - interrupted | |
672 | * -ENOBUFS - no backing object available in which to cache the block | |
673 | * 0 - block allocated | |
674 | */ | |
675 | int __fscache_alloc_page(struct fscache_cookie *cookie, | |
676 | struct page *page, | |
677 | gfp_t gfp) | |
678 | { | |
679 | struct fscache_retrieval *op; | |
680 | struct fscache_object *object; | |
8fb883f3 | 681 | bool wake_cookie = false; |
b5108822 DH |
682 | int ret; |
683 | ||
684 | _enter("%p,%p,,,", cookie, page); | |
685 | ||
686 | fscache_stat(&fscache_n_allocs); | |
687 | ||
688 | if (hlist_empty(&cookie->backing_objects)) | |
689 | goto nobufs; | |
690 | ||
691 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
692 | ASSERTCMP(page, !=, NULL); | |
693 | ||
ef778e7a DH |
694 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
695 | _leave(" = -ENOBUFS [invalidating]"); | |
696 | return -ENOBUFS; | |
697 | } | |
698 | ||
b5108822 DH |
699 | if (fscache_wait_for_deferred_lookup(cookie) < 0) |
700 | return -ERESTARTSYS; | |
701 | ||
1362729b | 702 | op = fscache_alloc_retrieval(cookie, page->mapping, NULL, NULL); |
b5108822 DH |
703 | if (!op) |
704 | return -ENOMEM; | |
1bb4b7f9 | 705 | atomic_set(&op->n_pages, 1); |
08c2e3d0 | 706 | trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_alloc_one); |
b5108822 DH |
707 | |
708 | spin_lock(&cookie->lock); | |
709 | ||
94d30ae9 DH |
710 | if (!fscache_cookie_enabled(cookie) || |
711 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
712 | goto nobufs_unlock; |
713 | object = hlist_entry(cookie->backing_objects.first, | |
714 | struct fscache_object, cookie_link); | |
715 | ||
8fb883f3 | 716 | __fscache_use_cookie(cookie); |
b5108822 | 717 | if (fscache_submit_op(object, &op->op) < 0) |
8fb883f3 | 718 | goto nobufs_unlock_dec; |
b5108822 DH |
719 | spin_unlock(&cookie->lock); |
720 | ||
721 | fscache_stat(&fscache_n_alloc_ops); | |
722 | ||
da9803bc DH |
723 | ret = fscache_wait_for_operation_activation( |
724 | object, &op->op, | |
60d543ca | 725 | __fscache_stat(&fscache_n_alloc_op_waits), |
d3b97ca4 | 726 | __fscache_stat(&fscache_n_allocs_object_dead)); |
60d543ca DH |
727 | if (ret < 0) |
728 | goto error; | |
b5108822 DH |
729 | |
730 | /* ask the cache to honour the operation */ | |
52bd75fd | 731 | fscache_stat(&fscache_n_cop_allocate_page); |
b5108822 | 732 | ret = object->cache->ops->allocate_page(op, page, gfp); |
52bd75fd | 733 | fscache_stat_d(&fscache_n_cop_allocate_page); |
b5108822 | 734 | |
5753c441 DH |
735 | error: |
736 | if (ret == -ERESTARTSYS) | |
737 | fscache_stat(&fscache_n_allocs_intr); | |
738 | else if (ret < 0) | |
b5108822 DH |
739 | fscache_stat(&fscache_n_allocs_nobufs); |
740 | else | |
741 | fscache_stat(&fscache_n_allocs_ok); | |
742 | ||
743 | fscache_put_retrieval(op); | |
744 | _leave(" = %d", ret); | |
745 | return ret; | |
746 | ||
8fb883f3 DH |
747 | nobufs_unlock_dec: |
748 | wake_cookie = __fscache_unuse_cookie(cookie); | |
b5108822 DH |
749 | nobufs_unlock: |
750 | spin_unlock(&cookie->lock); | |
a39caadf | 751 | fscache_put_retrieval(op); |
8fb883f3 DH |
752 | if (wake_cookie) |
753 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
754 | nobufs: |
755 | fscache_stat(&fscache_n_allocs_nobufs); | |
756 | _leave(" = -ENOBUFS"); | |
757 | return -ENOBUFS; | |
758 | } | |
759 | EXPORT_SYMBOL(__fscache_alloc_page); | |
760 | ||
5a6f282a MT |
761 | /* |
762 | * Unmark pages allocate in the readahead code path (via: | |
763 | * fscache_readpages_or_alloc) after delegating to the base filesystem | |
764 | */ | |
765 | void __fscache_readpages_cancel(struct fscache_cookie *cookie, | |
766 | struct list_head *pages) | |
767 | { | |
768 | struct page *page; | |
769 | ||
770 | list_for_each_entry(page, pages, lru) { | |
771 | if (PageFsCache(page)) | |
772 | __fscache_uncache_page(cookie, page); | |
773 | } | |
774 | } | |
775 | EXPORT_SYMBOL(__fscache_readpages_cancel); | |
776 | ||
b5108822 DH |
777 | /* |
778 | * release a write op reference | |
779 | */ | |
780 | static void fscache_release_write_op(struct fscache_operation *_op) | |
781 | { | |
782 | _enter("{OP%x}", _op->debug_id); | |
783 | } | |
784 | ||
785 | /* | |
786 | * perform the background storage of a page into the cache | |
787 | */ | |
788 | static void fscache_write_op(struct fscache_operation *_op) | |
789 | { | |
790 | struct fscache_storage *op = | |
791 | container_of(_op, struct fscache_storage, op); | |
792 | struct fscache_object *object = op->op.object; | |
1bccf513 | 793 | struct fscache_cookie *cookie; |
b5108822 DH |
794 | struct page *page; |
795 | unsigned n; | |
796 | void *results[1]; | |
797 | int ret; | |
798 | ||
799 | _enter("{OP%x,%d}", op->op.debug_id, atomic_read(&op->op.usage)); | |
800 | ||
2c984257 | 801 | again: |
b5108822 | 802 | spin_lock(&object->lock); |
1bccf513 | 803 | cookie = object->cookie; |
b5108822 | 804 | |
7ef001e9 | 805 | if (!fscache_object_is_active(object)) { |
b27ddd46 DH |
806 | /* If we get here, then the on-disk cache object likely no |
807 | * longer exists, so we should just cancel this write | |
808 | * operation. | |
7ef001e9 | 809 | */ |
b5108822 | 810 | spin_unlock(&object->lock); |
b27ddd46 | 811 | fscache_op_complete(&op->op, true); |
7ef001e9 DH |
812 | _leave(" [inactive]"); |
813 | return; | |
814 | } | |
815 | ||
816 | if (!cookie) { | |
817 | /* If we get here, then the cookie belonging to the object was | |
818 | * detached, probably by the cookie being withdrawn due to | |
819 | * memory pressure, which means that the pages we might write | |
820 | * to the cache from no longer exist - therefore, we can just | |
821 | * cancel this write operation. | |
822 | */ | |
823 | spin_unlock(&object->lock); | |
b27ddd46 | 824 | fscache_op_complete(&op->op, true); |
caaef690 DH |
825 | _leave(" [cancel] op{f=%lx s=%u} obj{s=%s f=%lx}", |
826 | _op->flags, _op->state, object->state->short_name, | |
827 | object->flags); | |
b5108822 DH |
828 | return; |
829 | } | |
830 | ||
1bccf513 DH |
831 | spin_lock(&cookie->stores_lock); |
832 | ||
b5108822 DH |
833 | fscache_stat(&fscache_n_store_calls); |
834 | ||
835 | /* find a page to store */ | |
08c2e3d0 | 836 | results[0] = NULL; |
b5108822 DH |
837 | page = NULL; |
838 | n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, 1, | |
839 | FSCACHE_COOKIE_PENDING_TAG); | |
08c2e3d0 | 840 | trace_fscache_gang_lookup(cookie, &op->op, results, n, op->store_limit); |
b5108822 DH |
841 | if (n != 1) |
842 | goto superseded; | |
843 | page = results[0]; | |
844 | _debug("gang %d [%lx]", n, page->index); | |
b5108822 | 845 | |
08a66859 DC |
846 | radix_tree_tag_set(&cookie->stores, page->index, |
847 | FSCACHE_COOKIE_STORING_TAG); | |
848 | radix_tree_tag_clear(&cookie->stores, page->index, | |
849 | FSCACHE_COOKIE_PENDING_TAG); | |
08c2e3d0 | 850 | trace_fscache_page(cookie, page, fscache_page_radix_pend2store); |
b5108822 | 851 | |
1bccf513 | 852 | spin_unlock(&cookie->stores_lock); |
b5108822 | 853 | spin_unlock(&object->lock); |
b5108822 | 854 | |
2c984257 DH |
855 | if (page->index >= op->store_limit) |
856 | goto discard_page; | |
857 | ||
08a66859 DC |
858 | fscache_stat(&fscache_n_store_pages); |
859 | fscache_stat(&fscache_n_cop_write_page); | |
860 | ret = object->cache->ops->write_page(op, page); | |
861 | fscache_stat_d(&fscache_n_cop_write_page); | |
08c2e3d0 | 862 | trace_fscache_wrote_page(cookie, page, &op->op, ret); |
08a66859 DC |
863 | fscache_end_page_write(object, page); |
864 | if (ret < 0) { | |
08a66859 | 865 | fscache_abort_object(object); |
1f372dff | 866 | fscache_op_complete(&op->op, true); |
08a66859 DC |
867 | } else { |
868 | fscache_enqueue_operation(&op->op); | |
b5108822 DH |
869 | } |
870 | ||
871 | _leave(""); | |
872 | return; | |
873 | ||
2c984257 DH |
874 | discard_page: |
875 | fscache_stat(&fscache_n_store_pages_over_limit); | |
08c2e3d0 | 876 | trace_fscache_wrote_page(cookie, page, &op->op, -ENOBUFS); |
2c984257 DH |
877 | fscache_end_page_write(object, page); |
878 | goto again; | |
879 | ||
b5108822 DH |
880 | superseded: |
881 | /* this writer is going away and there aren't any more things to | |
882 | * write */ | |
883 | _debug("cease"); | |
1bccf513 | 884 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
885 | clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags); |
886 | spin_unlock(&object->lock); | |
b27ddd46 | 887 | fscache_op_complete(&op->op, false); |
b5108822 DH |
888 | _leave(""); |
889 | } | |
890 | ||
ef778e7a DH |
891 | /* |
892 | * Clear the pages pending writing for invalidation | |
893 | */ | |
894 | void fscache_invalidate_writes(struct fscache_cookie *cookie) | |
895 | { | |
896 | struct page *page; | |
897 | void *results[16]; | |
898 | int n, i; | |
899 | ||
900 | _enter(""); | |
901 | ||
ee8be57b SAS |
902 | for (;;) { |
903 | spin_lock(&cookie->stores_lock); | |
904 | n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, | |
905 | ARRAY_SIZE(results), | |
906 | FSCACHE_COOKIE_PENDING_TAG); | |
907 | if (n == 0) { | |
908 | spin_unlock(&cookie->stores_lock); | |
909 | break; | |
910 | } | |
911 | ||
ef778e7a DH |
912 | for (i = n - 1; i >= 0; i--) { |
913 | page = results[i]; | |
914 | radix_tree_delete(&cookie->stores, page->index); | |
08c2e3d0 DH |
915 | trace_fscache_page(cookie, page, fscache_page_radix_delete); |
916 | trace_fscache_page(cookie, page, fscache_page_inval); | |
ef778e7a DH |
917 | } |
918 | ||
919 | spin_unlock(&cookie->stores_lock); | |
920 | ||
921 | for (i = n - 1; i >= 0; i--) | |
09cbfeaf | 922 | put_page(results[i]); |
ef778e7a DH |
923 | } |
924 | ||
d2138455 | 925 | wake_up_bit(&cookie->flags, 0); |
08c2e3d0 | 926 | trace_fscache_wake_cookie(cookie); |
d2138455 | 927 | |
ef778e7a DH |
928 | _leave(""); |
929 | } | |
930 | ||
b5108822 DH |
931 | /* |
932 | * request a page be stored in the cache | |
933 | * - returns: | |
934 | * -ENOMEM - out of memory, nothing done | |
935 | * -ENOBUFS - no backing object available in which to cache the page | |
936 | * 0 - dispatched a write - it'll call end_io_func() when finished | |
937 | * | |
938 | * if the cookie still has a backing object at this point, that object can be | |
939 | * in one of a few states with respect to storage processing: | |
940 | * | |
941 | * (1) negative lookup, object not yet created (FSCACHE_COOKIE_CREATING is | |
942 | * set) | |
943 | * | |
caaef690 | 944 | * (a) no writes yet |
b5108822 DH |
945 | * |
946 | * (b) writes deferred till post-creation (mark page for writing and | |
947 | * return immediately) | |
948 | * | |
949 | * (2) negative lookup, object created, initial fill being made from netfs | |
b5108822 DH |
950 | * |
951 | * (a) fill point not yet reached this page (mark page for writing and | |
952 | * return) | |
953 | * | |
954 | * (b) fill point passed this page (queue op to store this page) | |
955 | * | |
956 | * (3) object extant (queue op to store this page) | |
957 | * | |
958 | * any other state is invalid | |
959 | */ | |
960 | int __fscache_write_page(struct fscache_cookie *cookie, | |
961 | struct page *page, | |
ee1235a9 | 962 | loff_t object_size, |
b5108822 DH |
963 | gfp_t gfp) |
964 | { | |
965 | struct fscache_storage *op; | |
966 | struct fscache_object *object; | |
8fb883f3 | 967 | bool wake_cookie = false; |
b5108822 DH |
968 | int ret; |
969 | ||
970 | _enter("%p,%x,", cookie, (u32) page->flags); | |
971 | ||
972 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
973 | ASSERT(PageFsCache(page)); | |
974 | ||
975 | fscache_stat(&fscache_n_stores); | |
976 | ||
ef778e7a DH |
977 | if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { |
978 | _leave(" = -ENOBUFS [invalidating]"); | |
979 | return -ENOBUFS; | |
980 | } | |
981 | ||
5f4f9f4a | 982 | op = kzalloc(sizeof(*op), GFP_NOIO | __GFP_NOMEMALLOC | __GFP_NORETRY); |
b5108822 DH |
983 | if (!op) |
984 | goto nomem; | |
985 | ||
08c2e3d0 | 986 | fscache_operation_init(cookie, &op->op, fscache_write_op, NULL, |
8af7c124 | 987 | fscache_release_write_op); |
1362729b DH |
988 | op->op.flags = FSCACHE_OP_ASYNC | |
989 | (1 << FSCACHE_OP_WAITING) | | |
990 | (1 << FSCACHE_OP_UNUSE_COOKIE); | |
b5108822 | 991 | |
5e4c0d97 | 992 | ret = radix_tree_maybe_preload(gfp & ~__GFP_HIGHMEM); |
b5108822 DH |
993 | if (ret < 0) |
994 | goto nomem_free; | |
995 | ||
08c2e3d0 DH |
996 | trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_write_one); |
997 | ||
b5108822 DH |
998 | ret = -ENOBUFS; |
999 | spin_lock(&cookie->lock); | |
1000 | ||
94d30ae9 DH |
1001 | if (!fscache_cookie_enabled(cookie) || |
1002 | hlist_empty(&cookie->backing_objects)) | |
b5108822 DH |
1003 | goto nobufs; |
1004 | object = hlist_entry(cookie->backing_objects.first, | |
1005 | struct fscache_object, cookie_link); | |
1006 | if (test_bit(FSCACHE_IOERROR, &object->cache->flags)) | |
1007 | goto nobufs; | |
1008 | ||
08c2e3d0 DH |
1009 | trace_fscache_page(cookie, page, fscache_page_write); |
1010 | ||
b5108822 DH |
1011 | /* add the page to the pending-storage radix tree on the backing |
1012 | * object */ | |
1013 | spin_lock(&object->lock); | |
ee1235a9 DH |
1014 | |
1015 | if (object->store_limit_l != object_size) | |
1016 | fscache_set_store_limit(object, object_size); | |
1017 | ||
1bccf513 | 1018 | spin_lock(&cookie->stores_lock); |
b5108822 DH |
1019 | |
1020 | _debug("store limit %llx", (unsigned long long) object->store_limit); | |
1021 | ||
1022 | ret = radix_tree_insert(&cookie->stores, page->index, page); | |
1023 | if (ret < 0) { | |
1024 | if (ret == -EEXIST) | |
1025 | goto already_queued; | |
1026 | _debug("insert failed %d", ret); | |
1027 | goto nobufs_unlock_obj; | |
1028 | } | |
1029 | ||
08c2e3d0 | 1030 | trace_fscache_page(cookie, page, fscache_page_radix_insert); |
b5108822 DH |
1031 | radix_tree_tag_set(&cookie->stores, page->index, |
1032 | FSCACHE_COOKIE_PENDING_TAG); | |
08c2e3d0 | 1033 | trace_fscache_page(cookie, page, fscache_page_radix_set_pend); |
09cbfeaf | 1034 | get_page(page); |
b5108822 DH |
1035 | |
1036 | /* we only want one writer at a time, but we do need to queue new | |
1037 | * writers after exclusive ops */ | |
1038 | if (test_and_set_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags)) | |
1039 | goto already_pending; | |
1040 | ||
1bccf513 | 1041 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
1042 | spin_unlock(&object->lock); |
1043 | ||
1044 | op->op.debug_id = atomic_inc_return(&fscache_op_debug_id); | |
1045 | op->store_limit = object->store_limit; | |
1046 | ||
8fb883f3 | 1047 | __fscache_use_cookie(cookie); |
b5108822 DH |
1048 | if (fscache_submit_op(object, &op->op) < 0) |
1049 | goto submit_failed; | |
1050 | ||
1051 | spin_unlock(&cookie->lock); | |
1052 | radix_tree_preload_end(); | |
1053 | fscache_stat(&fscache_n_store_ops); | |
1054 | fscache_stat(&fscache_n_stores_ok); | |
1055 | ||
8af7c124 | 1056 | /* the work queue now carries its own ref on the object */ |
b5108822 DH |
1057 | fscache_put_operation(&op->op); |
1058 | _leave(" = 0"); | |
1059 | return 0; | |
1060 | ||
1061 | already_queued: | |
1062 | fscache_stat(&fscache_n_stores_again); | |
1063 | already_pending: | |
1bccf513 | 1064 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
1065 | spin_unlock(&object->lock); |
1066 | spin_unlock(&cookie->lock); | |
1067 | radix_tree_preload_end(); | |
a39caadf | 1068 | fscache_put_operation(&op->op); |
b5108822 DH |
1069 | fscache_stat(&fscache_n_stores_ok); |
1070 | _leave(" = 0"); | |
1071 | return 0; | |
1072 | ||
1073 | submit_failed: | |
1bccf513 | 1074 | spin_lock(&cookie->stores_lock); |
b5108822 | 1075 | radix_tree_delete(&cookie->stores, page->index); |
08c2e3d0 | 1076 | trace_fscache_page(cookie, page, fscache_page_radix_delete); |
1bccf513 | 1077 | spin_unlock(&cookie->stores_lock); |
8fb883f3 | 1078 | wake_cookie = __fscache_unuse_cookie(cookie); |
09cbfeaf | 1079 | put_page(page); |
b5108822 DH |
1080 | ret = -ENOBUFS; |
1081 | goto nobufs; | |
1082 | ||
1083 | nobufs_unlock_obj: | |
1147d0f9 | 1084 | spin_unlock(&cookie->stores_lock); |
b5108822 DH |
1085 | spin_unlock(&object->lock); |
1086 | nobufs: | |
1087 | spin_unlock(&cookie->lock); | |
1088 | radix_tree_preload_end(); | |
a39caadf | 1089 | fscache_put_operation(&op->op); |
8fb883f3 DH |
1090 | if (wake_cookie) |
1091 | __fscache_wake_unused_cookie(cookie); | |
b5108822 DH |
1092 | fscache_stat(&fscache_n_stores_nobufs); |
1093 | _leave(" = -ENOBUFS"); | |
1094 | return -ENOBUFS; | |
1095 | ||
1096 | nomem_free: | |
a39caadf | 1097 | fscache_put_operation(&op->op); |
b5108822 DH |
1098 | nomem: |
1099 | fscache_stat(&fscache_n_stores_oom); | |
1100 | _leave(" = -ENOMEM"); | |
1101 | return -ENOMEM; | |
1102 | } | |
1103 | EXPORT_SYMBOL(__fscache_write_page); | |
1104 | ||
1105 | /* | |
1106 | * remove a page from the cache | |
1107 | */ | |
1108 | void __fscache_uncache_page(struct fscache_cookie *cookie, struct page *page) | |
1109 | { | |
1110 | struct fscache_object *object; | |
1111 | ||
1112 | _enter(",%p", page); | |
1113 | ||
1114 | ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); | |
1115 | ASSERTCMP(page, !=, NULL); | |
1116 | ||
1117 | fscache_stat(&fscache_n_uncaches); | |
1118 | ||
1119 | /* cache withdrawal may beat us to it */ | |
1120 | if (!PageFsCache(page)) | |
1121 | goto done; | |
1122 | ||
08c2e3d0 DH |
1123 | trace_fscache_page(cookie, page, fscache_page_uncache); |
1124 | ||
b5108822 DH |
1125 | /* get the object */ |
1126 | spin_lock(&cookie->lock); | |
1127 | ||
1128 | if (hlist_empty(&cookie->backing_objects)) { | |
1129 | ClearPageFsCache(page); | |
1130 | goto done_unlock; | |
1131 | } | |
1132 | ||
1133 | object = hlist_entry(cookie->backing_objects.first, | |
1134 | struct fscache_object, cookie_link); | |
1135 | ||
1136 | /* there might now be stuff on disk we could read */ | |
1137 | clear_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); | |
1138 | ||
1139 | /* only invoke the cache backend if we managed to mark the page | |
1140 | * uncached here; this deals with synchronisation vs withdrawal */ | |
1141 | if (TestClearPageFsCache(page) && | |
1142 | object->cache->ops->uncache_page) { | |
1143 | /* the cache backend releases the cookie lock */ | |
52bd75fd | 1144 | fscache_stat(&fscache_n_cop_uncache_page); |
b5108822 | 1145 | object->cache->ops->uncache_page(object, page); |
52bd75fd | 1146 | fscache_stat_d(&fscache_n_cop_uncache_page); |
b5108822 DH |
1147 | goto done; |
1148 | } | |
1149 | ||
1150 | done_unlock: | |
1151 | spin_unlock(&cookie->lock); | |
1152 | done: | |
1153 | _leave(""); | |
1154 | } | |
1155 | EXPORT_SYMBOL(__fscache_uncache_page); | |
1156 | ||
c4d6d8db DH |
1157 | /** |
1158 | * fscache_mark_page_cached - Mark a page as being cached | |
1159 | * @op: The retrieval op pages are being marked for | |
1160 | * @page: The page to be marked | |
1161 | * | |
1162 | * Mark a netfs page as being cached. After this is called, the netfs | |
1163 | * must call fscache_uncache_page() to remove the mark. | |
1164 | */ | |
1165 | void fscache_mark_page_cached(struct fscache_retrieval *op, struct page *page) | |
1166 | { | |
1167 | struct fscache_cookie *cookie = op->op.object->cookie; | |
1168 | ||
1169 | #ifdef CONFIG_FSCACHE_STATS | |
1170 | atomic_inc(&fscache_n_marks); | |
1171 | #endif | |
1172 | ||
08c2e3d0 DH |
1173 | trace_fscache_page(cookie, page, fscache_page_cached); |
1174 | ||
c4d6d8db DH |
1175 | _debug("- mark %p{%lx}", page, page->index); |
1176 | if (TestSetPageFsCache(page)) { | |
1177 | static bool once_only; | |
1178 | if (!once_only) { | |
1179 | once_only = true; | |
36dfd116 FF |
1180 | pr_warn("Cookie type %s marked page %lx multiple times\n", |
1181 | cookie->def->name, page->index); | |
c4d6d8db DH |
1182 | } |
1183 | } | |
1184 | ||
1185 | if (cookie->def->mark_page_cached) | |
1186 | cookie->def->mark_page_cached(cookie->netfs_data, | |
1187 | op->mapping, page); | |
1188 | } | |
1189 | EXPORT_SYMBOL(fscache_mark_page_cached); | |
1190 | ||
b5108822 DH |
1191 | /** |
1192 | * fscache_mark_pages_cached - Mark pages as being cached | |
1193 | * @op: The retrieval op pages are being marked for | |
1194 | * @pagevec: The pages to be marked | |
1195 | * | |
1196 | * Mark a bunch of netfs pages as being cached. After this is called, | |
1197 | * the netfs must call fscache_uncache_page() to remove the mark. | |
1198 | */ | |
1199 | void fscache_mark_pages_cached(struct fscache_retrieval *op, | |
1200 | struct pagevec *pagevec) | |
1201 | { | |
b5108822 DH |
1202 | unsigned long loop; |
1203 | ||
c4d6d8db DH |
1204 | for (loop = 0; loop < pagevec->nr; loop++) |
1205 | fscache_mark_page_cached(op, pagevec->pages[loop]); | |
b5108822 | 1206 | |
b5108822 DH |
1207 | pagevec_reinit(pagevec); |
1208 | } | |
1209 | EXPORT_SYMBOL(fscache_mark_pages_cached); | |
c902ce1b DH |
1210 | |
1211 | /* | |
1212 | * Uncache all the pages in an inode that are marked PG_fscache, assuming them | |
1213 | * to be associated with the given cookie. | |
1214 | */ | |
1215 | void __fscache_uncache_all_inode_pages(struct fscache_cookie *cookie, | |
1216 | struct inode *inode) | |
1217 | { | |
1218 | struct address_space *mapping = inode->i_mapping; | |
1219 | struct pagevec pvec; | |
1220 | pgoff_t next; | |
1221 | int i; | |
1222 | ||
1223 | _enter("%p,%p", cookie, inode); | |
1224 | ||
1225 | if (!mapping || mapping->nrpages == 0) { | |
1226 | _leave(" [no pages]"); | |
1227 | return; | |
1228 | } | |
1229 | ||
86679820 | 1230 | pagevec_init(&pvec); |
c902ce1b | 1231 | next = 0; |
b307d465 | 1232 | do { |
397162ff | 1233 | if (!pagevec_lookup(&pvec, mapping, &next)) |
b307d465 | 1234 | break; |
c902ce1b DH |
1235 | for (i = 0; i < pagevec_count(&pvec); i++) { |
1236 | struct page *page = pvec.pages[i]; | |
c902ce1b DH |
1237 | if (PageFsCache(page)) { |
1238 | __fscache_wait_on_page_write(cookie, page); | |
1239 | __fscache_uncache_page(cookie, page); | |
1240 | } | |
1241 | } | |
1242 | pagevec_release(&pvec); | |
1243 | cond_resched(); | |
d72dc8a2 | 1244 | } while (next); |
c902ce1b DH |
1245 | |
1246 | _leave(""); | |
1247 | } | |
1248 | EXPORT_SYMBOL(__fscache_uncache_all_inode_pages); |