1 /* Cache page management and data I/O routines
3 * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
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.
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>
20 * check to see if a page is being written to the cache
22 bool __fscache_check_page_write(struct fscache_cookie *cookie, struct page *page)
27 val = radix_tree_lookup(&cookie->stores, page->index);
32 EXPORT_SYMBOL(__fscache_check_page_write);
35 * wait for a page to finish being written to the cache
37 void __fscache_wait_on_page_write(struct fscache_cookie *cookie, struct page *page)
39 wait_queue_head_t *wq = bit_waitqueue(&cookie->flags, 0);
41 wait_event(*wq, !__fscache_check_page_write(cookie, page));
43 EXPORT_SYMBOL(__fscache_wait_on_page_write);
46 * decide whether a page can be released, possibly by cancelling a store to it
47 * - we're allowed to sleep if __GFP_WAIT is flagged
49 bool __fscache_maybe_release_page(struct fscache_cookie *cookie,
56 _enter("%p,%p,%x", cookie, page, gfp);
59 val = radix_tree_lookup(&cookie->stores, page->index);
62 fscache_stat(&fscache_n_store_vmscan_not_storing);
63 __fscache_uncache_page(cookie, page);
67 /* see if the page is actually undergoing storage - if so we can't get
68 * rid of it till the cache has finished with it */
69 if (radix_tree_tag_get(&cookie->stores, page->index,
70 FSCACHE_COOKIE_STORING_TAG)) {
75 /* the page is pending storage, so we attempt to cancel the store and
76 * discard the store request so that the page can be reclaimed */
77 spin_lock(&cookie->stores_lock);
80 if (radix_tree_tag_get(&cookie->stores, page->index,
81 FSCACHE_COOKIE_STORING_TAG)) {
82 /* the page started to undergo storage whilst we were looking,
83 * so now we can only wait or return */
84 spin_unlock(&cookie->stores_lock);
88 xpage = radix_tree_delete(&cookie->stores, page->index);
89 spin_unlock(&cookie->stores_lock);
92 fscache_stat(&fscache_n_store_vmscan_cancelled);
93 fscache_stat(&fscache_n_store_radix_deletes);
94 ASSERTCMP(xpage, ==, page);
96 fscache_stat(&fscache_n_store_vmscan_gone);
99 wake_up_bit(&cookie->flags, 0);
101 page_cache_release(xpage);
102 __fscache_uncache_page(cookie, page);
106 /* we might want to wait here, but that could deadlock the allocator as
107 * the slow-work threads writing to the cache may all end up sleeping
108 * on memory allocation */
109 fscache_stat(&fscache_n_store_vmscan_busy);
112 EXPORT_SYMBOL(__fscache_maybe_release_page);
115 * note that a page has finished being written to the cache
117 static void fscache_end_page_write(struct fscache_object *object,
120 struct fscache_cookie *cookie;
121 struct page *xpage = NULL;
123 spin_lock(&object->lock);
124 cookie = object->cookie;
126 /* delete the page from the tree if it is now no longer
128 spin_lock(&cookie->stores_lock);
129 radix_tree_tag_clear(&cookie->stores, page->index,
130 FSCACHE_COOKIE_STORING_TAG);
131 if (!radix_tree_tag_get(&cookie->stores, page->index,
132 FSCACHE_COOKIE_PENDING_TAG)) {
133 fscache_stat(&fscache_n_store_radix_deletes);
134 xpage = radix_tree_delete(&cookie->stores, page->index);
136 spin_unlock(&cookie->stores_lock);
137 wake_up_bit(&cookie->flags, 0);
139 spin_unlock(&object->lock);
141 page_cache_release(xpage);
145 * actually apply the changed attributes to a cache object
147 static void fscache_attr_changed_op(struct fscache_operation *op)
149 struct fscache_object *object = op->object;
152 _enter("{OBJ%x OP%x}", object->debug_id, op->debug_id);
154 fscache_stat(&fscache_n_attr_changed_calls);
156 if (fscache_object_is_active(object)) {
157 fscache_set_op_state(op, "CallFS");
158 fscache_stat(&fscache_n_cop_attr_changed);
159 ret = object->cache->ops->attr_changed(object);
160 fscache_stat_d(&fscache_n_cop_attr_changed);
161 fscache_set_op_state(op, "Done");
163 fscache_abort_object(object);
170 * notification that the attributes on an object have changed
172 int __fscache_attr_changed(struct fscache_cookie *cookie)
174 struct fscache_operation *op;
175 struct fscache_object *object;
177 _enter("%p", cookie);
179 ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
181 fscache_stat(&fscache_n_attr_changed);
183 op = kzalloc(sizeof(*op), GFP_KERNEL);
185 fscache_stat(&fscache_n_attr_changed_nomem);
186 _leave(" = -ENOMEM");
190 fscache_operation_init(op, NULL);
191 fscache_operation_init_slow(op, fscache_attr_changed_op);
192 op->flags = FSCACHE_OP_SLOW | (1 << FSCACHE_OP_EXCLUSIVE);
193 fscache_set_op_name(op, "Attr");
195 spin_lock(&cookie->lock);
197 if (hlist_empty(&cookie->backing_objects))
199 object = hlist_entry(cookie->backing_objects.first,
200 struct fscache_object, cookie_link);
202 if (fscache_submit_exclusive_op(object, op) < 0)
204 spin_unlock(&cookie->lock);
205 fscache_stat(&fscache_n_attr_changed_ok);
206 fscache_put_operation(op);
211 spin_unlock(&cookie->lock);
213 fscache_stat(&fscache_n_attr_changed_nobufs);
214 _leave(" = %d", -ENOBUFS);
217 EXPORT_SYMBOL(__fscache_attr_changed);
220 * handle secondary execution given to a retrieval op on behalf of the
223 static void fscache_retrieval_work(struct work_struct *work)
225 struct fscache_retrieval *op =
226 container_of(work, struct fscache_retrieval, op.fast_work);
229 _enter("{OP%x}", op->op.debug_id);
232 op->op.processor(&op->op);
233 fscache_hist(fscache_ops_histogram, start);
234 fscache_put_operation(&op->op);
238 * release a retrieval op reference
240 static void fscache_release_retrieval_op(struct fscache_operation *_op)
242 struct fscache_retrieval *op =
243 container_of(_op, struct fscache_retrieval, op);
245 _enter("{OP%x}", op->op.debug_id);
247 fscache_hist(fscache_retrieval_histogram, op->start_time);
249 fscache_put_context(op->op.object->cookie, op->context);
255 * allocate a retrieval op
257 static struct fscache_retrieval *fscache_alloc_retrieval(
258 struct address_space *mapping,
259 fscache_rw_complete_t end_io_func,
262 struct fscache_retrieval *op;
264 /* allocate a retrieval operation and attempt to submit it */
265 op = kzalloc(sizeof(*op), GFP_NOIO);
267 fscache_stat(&fscache_n_retrievals_nomem);
271 fscache_operation_init(&op->op, fscache_release_retrieval_op);
272 op->op.flags = FSCACHE_OP_MYTHREAD | (1 << FSCACHE_OP_WAITING);
273 op->mapping = mapping;
274 op->end_io_func = end_io_func;
275 op->context = context;
276 op->start_time = jiffies;
277 INIT_WORK(&op->op.fast_work, fscache_retrieval_work);
278 INIT_LIST_HEAD(&op->to_do);
279 fscache_set_op_name(&op->op, "Retr");
284 * wait for a deferred lookup to complete
286 static int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)
292 if (!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) {
293 _leave(" = 0 [imm]");
297 fscache_stat(&fscache_n_retrievals_wait);
300 if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP,
301 fscache_wait_bit_interruptible,
302 TASK_INTERRUPTIBLE) != 0) {
303 fscache_stat(&fscache_n_retrievals_intr);
304 _leave(" = -ERESTARTSYS");
308 ASSERT(!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags));
311 fscache_hist(fscache_retrieval_delay_histogram, jif);
312 _leave(" = 0 [dly]");
317 * wait for an object to become active (or dead)
319 static int fscache_wait_for_retrieval_activation(struct fscache_object *object,
320 struct fscache_retrieval *op,
321 atomic_t *stat_op_waits,
322 atomic_t *stat_object_dead)
326 if (!test_bit(FSCACHE_OP_WAITING, &op->op.flags))
330 fscache_stat(stat_op_waits);
331 if (wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
332 fscache_wait_bit_interruptible,
333 TASK_INTERRUPTIBLE) < 0) {
334 ret = fscache_cancel_op(&op->op);
338 /* it's been removed from the pending queue by another party,
339 * so we should get to run shortly */
340 wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
341 fscache_wait_bit, TASK_UNINTERRUPTIBLE);
346 if (unlikely(fscache_object_is_dead(object))) {
347 fscache_stat(stat_object_dead);
354 * read a page from the cache or allocate a block in which to store it
356 * -ENOMEM - out of memory, nothing done
357 * -ERESTARTSYS - interrupted
358 * -ENOBUFS - no backing object available in which to cache the block
359 * -ENODATA - no data available in the backing object for this block
360 * 0 - dispatched a read - it'll call end_io_func() when finished
362 int __fscache_read_or_alloc_page(struct fscache_cookie *cookie,
364 fscache_rw_complete_t end_io_func,
368 struct fscache_retrieval *op;
369 struct fscache_object *object;
372 _enter("%p,%p,,,", cookie, page);
374 fscache_stat(&fscache_n_retrievals);
376 if (hlist_empty(&cookie->backing_objects))
379 ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
380 ASSERTCMP(page, !=, NULL);
382 if (fscache_wait_for_deferred_lookup(cookie) < 0)
385 op = fscache_alloc_retrieval(page->mapping, end_io_func, context);
387 _leave(" = -ENOMEM");
390 fscache_set_op_name(&op->op, "RetrRA1");
392 spin_lock(&cookie->lock);
394 if (hlist_empty(&cookie->backing_objects))
396 object = hlist_entry(cookie->backing_objects.first,
397 struct fscache_object, cookie_link);
399 ASSERTCMP(object->state, >, FSCACHE_OBJECT_LOOKING_UP);
401 atomic_inc(&object->n_reads);
402 set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
404 if (fscache_submit_op(object, &op->op) < 0)
406 spin_unlock(&cookie->lock);
408 fscache_stat(&fscache_n_retrieval_ops);
410 /* pin the netfs read context in case we need to do the actual netfs
411 * read because we've encountered a cache read failure */
412 fscache_get_context(object->cookie, op->context);
414 /* we wait for the operation to become active, and then process it
415 * *here*, in this thread, and not in the thread pool */
416 ret = fscache_wait_for_retrieval_activation(
418 __fscache_stat(&fscache_n_retrieval_op_waits),
419 __fscache_stat(&fscache_n_retrievals_object_dead));
423 /* ask the cache to honour the operation */
424 if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) {
425 fscache_stat(&fscache_n_cop_allocate_page);
426 ret = object->cache->ops->allocate_page(op, page, gfp);
427 fscache_stat_d(&fscache_n_cop_allocate_page);
431 fscache_stat(&fscache_n_cop_read_or_alloc_page);
432 ret = object->cache->ops->read_or_alloc_page(op, page, gfp);
433 fscache_stat_d(&fscache_n_cop_read_or_alloc_page);
438 fscache_stat(&fscache_n_retrievals_nomem);
439 else if (ret == -ERESTARTSYS)
440 fscache_stat(&fscache_n_retrievals_intr);
441 else if (ret == -ENODATA)
442 fscache_stat(&fscache_n_retrievals_nodata);
444 fscache_stat(&fscache_n_retrievals_nobufs);
446 fscache_stat(&fscache_n_retrievals_ok);
448 fscache_put_retrieval(op);
449 _leave(" = %d", ret);
453 spin_unlock(&cookie->lock);
456 fscache_stat(&fscache_n_retrievals_nobufs);
457 _leave(" = -ENOBUFS");
460 EXPORT_SYMBOL(__fscache_read_or_alloc_page);
463 * read a list of page from the cache or allocate a block in which to store
466 * -ENOMEM - out of memory, some pages may be being read
467 * -ERESTARTSYS - interrupted, some pages may be being read
468 * -ENOBUFS - no backing object or space available in which to cache any
469 * pages not being read
470 * -ENODATA - no data available in the backing object for some or all of
472 * 0 - dispatched a read on all pages
474 * end_io_func() will be called for each page read from the cache as it is
475 * finishes being read
477 * any pages for which a read is dispatched will be removed from pages and
480 int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
481 struct address_space *mapping,
482 struct list_head *pages,
484 fscache_rw_complete_t end_io_func,
488 struct fscache_retrieval *op;
489 struct fscache_object *object;
492 _enter("%p,,%d,,,", cookie, *nr_pages);
494 fscache_stat(&fscache_n_retrievals);
496 if (hlist_empty(&cookie->backing_objects))
499 ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
500 ASSERTCMP(*nr_pages, >, 0);
501 ASSERT(!list_empty(pages));
503 if (fscache_wait_for_deferred_lookup(cookie) < 0)
506 op = fscache_alloc_retrieval(mapping, end_io_func, context);
509 fscache_set_op_name(&op->op, "RetrRAN");
511 spin_lock(&cookie->lock);
513 if (hlist_empty(&cookie->backing_objects))
515 object = hlist_entry(cookie->backing_objects.first,
516 struct fscache_object, cookie_link);
518 atomic_inc(&object->n_reads);
519 set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
521 if (fscache_submit_op(object, &op->op) < 0)
523 spin_unlock(&cookie->lock);
525 fscache_stat(&fscache_n_retrieval_ops);
527 /* pin the netfs read context in case we need to do the actual netfs
528 * read because we've encountered a cache read failure */
529 fscache_get_context(object->cookie, op->context);
531 /* we wait for the operation to become active, and then process it
532 * *here*, in this thread, and not in the thread pool */
533 ret = fscache_wait_for_retrieval_activation(
535 __fscache_stat(&fscache_n_retrieval_op_waits),
536 __fscache_stat(&fscache_n_retrievals_object_dead));
540 /* ask the cache to honour the operation */
541 if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) {
542 fscache_stat(&fscache_n_cop_allocate_pages);
543 ret = object->cache->ops->allocate_pages(
544 op, pages, nr_pages, gfp);
545 fscache_stat_d(&fscache_n_cop_allocate_pages);
547 fscache_stat(&fscache_n_cop_read_or_alloc_pages);
548 ret = object->cache->ops->read_or_alloc_pages(
549 op, pages, nr_pages, gfp);
550 fscache_stat_d(&fscache_n_cop_read_or_alloc_pages);
555 fscache_stat(&fscache_n_retrievals_nomem);
556 else if (ret == -ERESTARTSYS)
557 fscache_stat(&fscache_n_retrievals_intr);
558 else if (ret == -ENODATA)
559 fscache_stat(&fscache_n_retrievals_nodata);
561 fscache_stat(&fscache_n_retrievals_nobufs);
563 fscache_stat(&fscache_n_retrievals_ok);
565 fscache_put_retrieval(op);
566 _leave(" = %d", ret);
570 spin_unlock(&cookie->lock);
573 fscache_stat(&fscache_n_retrievals_nobufs);
574 _leave(" = -ENOBUFS");
577 EXPORT_SYMBOL(__fscache_read_or_alloc_pages);
580 * allocate a block in the cache on which to store a page
582 * -ENOMEM - out of memory, nothing done
583 * -ERESTARTSYS - interrupted
584 * -ENOBUFS - no backing object available in which to cache the block
585 * 0 - block allocated
587 int __fscache_alloc_page(struct fscache_cookie *cookie,
591 struct fscache_retrieval *op;
592 struct fscache_object *object;
595 _enter("%p,%p,,,", cookie, page);
597 fscache_stat(&fscache_n_allocs);
599 if (hlist_empty(&cookie->backing_objects))
602 ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
603 ASSERTCMP(page, !=, NULL);
605 if (fscache_wait_for_deferred_lookup(cookie) < 0)
608 op = fscache_alloc_retrieval(page->mapping, NULL, NULL);
611 fscache_set_op_name(&op->op, "RetrAL1");
613 spin_lock(&cookie->lock);
615 if (hlist_empty(&cookie->backing_objects))
617 object = hlist_entry(cookie->backing_objects.first,
618 struct fscache_object, cookie_link);
620 if (fscache_submit_op(object, &op->op) < 0)
622 spin_unlock(&cookie->lock);
624 fscache_stat(&fscache_n_alloc_ops);
626 ret = fscache_wait_for_retrieval_activation(
628 __fscache_stat(&fscache_n_alloc_op_waits),
629 __fscache_stat(&fscache_n_allocs_object_dead));
633 /* ask the cache to honour the operation */
634 fscache_stat(&fscache_n_cop_allocate_page);
635 ret = object->cache->ops->allocate_page(op, page, gfp);
636 fscache_stat_d(&fscache_n_cop_allocate_page);
639 if (ret == -ERESTARTSYS)
640 fscache_stat(&fscache_n_allocs_intr);
642 fscache_stat(&fscache_n_allocs_nobufs);
644 fscache_stat(&fscache_n_allocs_ok);
646 fscache_put_retrieval(op);
647 _leave(" = %d", ret);
651 spin_unlock(&cookie->lock);
654 fscache_stat(&fscache_n_allocs_nobufs);
655 _leave(" = -ENOBUFS");
658 EXPORT_SYMBOL(__fscache_alloc_page);
661 * release a write op reference
663 static void fscache_release_write_op(struct fscache_operation *_op)
665 _enter("{OP%x}", _op->debug_id);
669 * perform the background storage of a page into the cache
671 static void fscache_write_op(struct fscache_operation *_op)
673 struct fscache_storage *op =
674 container_of(_op, struct fscache_storage, op);
675 struct fscache_object *object = op->op.object;
676 struct fscache_cookie *cookie;
682 _enter("{OP%x,%d}", op->op.debug_id, atomic_read(&op->op.usage));
684 fscache_set_op_state(&op->op, "GetPage");
686 spin_lock(&object->lock);
687 cookie = object->cookie;
689 if (!fscache_object_is_active(object) || !cookie) {
690 spin_unlock(&object->lock);
695 spin_lock(&cookie->stores_lock);
697 fscache_stat(&fscache_n_store_calls);
699 /* find a page to store */
701 n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, 1,
702 FSCACHE_COOKIE_PENDING_TAG);
706 _debug("gang %d [%lx]", n, page->index);
707 if (page->index > op->store_limit) {
708 fscache_stat(&fscache_n_store_pages_over_limit);
713 radix_tree_tag_set(&cookie->stores, page->index,
714 FSCACHE_COOKIE_STORING_TAG);
715 radix_tree_tag_clear(&cookie->stores, page->index,
716 FSCACHE_COOKIE_PENDING_TAG);
719 spin_unlock(&cookie->stores_lock);
720 spin_unlock(&object->lock);
723 fscache_set_op_state(&op->op, "Store");
724 fscache_stat(&fscache_n_store_pages);
725 fscache_stat(&fscache_n_cop_write_page);
726 ret = object->cache->ops->write_page(op, page);
727 fscache_stat_d(&fscache_n_cop_write_page);
728 fscache_set_op_state(&op->op, "EndWrite");
729 fscache_end_page_write(object, page);
731 fscache_set_op_state(&op->op, "Abort");
732 fscache_abort_object(object);
734 fscache_enqueue_operation(&op->op);
742 /* this writer is going away and there aren't any more things to
745 spin_unlock(&cookie->stores_lock);
746 clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
747 spin_unlock(&object->lock);
752 * request a page be stored in the cache
754 * -ENOMEM - out of memory, nothing done
755 * -ENOBUFS - no backing object available in which to cache the page
756 * 0 - dispatched a write - it'll call end_io_func() when finished
758 * if the cookie still has a backing object at this point, that object can be
759 * in one of a few states with respect to storage processing:
761 * (1) negative lookup, object not yet created (FSCACHE_COOKIE_CREATING is
764 * (a) no writes yet (set FSCACHE_COOKIE_PENDING_FILL and queue deferred
767 * (b) writes deferred till post-creation (mark page for writing and
768 * return immediately)
770 * (2) negative lookup, object created, initial fill being made from netfs
771 * (FSCACHE_COOKIE_INITIAL_FILL is set)
773 * (a) fill point not yet reached this page (mark page for writing and
776 * (b) fill point passed this page (queue op to store this page)
778 * (3) object extant (queue op to store this page)
780 * any other state is invalid
782 int __fscache_write_page(struct fscache_cookie *cookie,
786 struct fscache_storage *op;
787 struct fscache_object *object;
790 _enter("%p,%x,", cookie, (u32) page->flags);
792 ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
793 ASSERT(PageFsCache(page));
795 fscache_stat(&fscache_n_stores);
797 op = kzalloc(sizeof(*op), GFP_NOIO);
801 fscache_operation_init(&op->op, fscache_release_write_op);
802 fscache_operation_init_slow(&op->op, fscache_write_op);
803 op->op.flags = FSCACHE_OP_SLOW | (1 << FSCACHE_OP_WAITING);
804 fscache_set_op_name(&op->op, "Write1");
806 ret = radix_tree_preload(gfp & ~__GFP_HIGHMEM);
811 spin_lock(&cookie->lock);
813 if (hlist_empty(&cookie->backing_objects))
815 object = hlist_entry(cookie->backing_objects.first,
816 struct fscache_object, cookie_link);
817 if (test_bit(FSCACHE_IOERROR, &object->cache->flags))
820 /* add the page to the pending-storage radix tree on the backing
822 spin_lock(&object->lock);
823 spin_lock(&cookie->stores_lock);
825 _debug("store limit %llx", (unsigned long long) object->store_limit);
827 ret = radix_tree_insert(&cookie->stores, page->index, page);
831 _debug("insert failed %d", ret);
832 goto nobufs_unlock_obj;
835 radix_tree_tag_set(&cookie->stores, page->index,
836 FSCACHE_COOKIE_PENDING_TAG);
837 page_cache_get(page);
839 /* we only want one writer at a time, but we do need to queue new
840 * writers after exclusive ops */
841 if (test_and_set_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags))
842 goto already_pending;
844 spin_unlock(&cookie->stores_lock);
845 spin_unlock(&object->lock);
847 op->op.debug_id = atomic_inc_return(&fscache_op_debug_id);
848 op->store_limit = object->store_limit;
850 if (fscache_submit_op(object, &op->op) < 0)
853 spin_unlock(&cookie->lock);
854 radix_tree_preload_end();
855 fscache_stat(&fscache_n_store_ops);
856 fscache_stat(&fscache_n_stores_ok);
858 /* the slow work queue now carries its own ref on the object */
859 fscache_put_operation(&op->op);
864 fscache_stat(&fscache_n_stores_again);
866 spin_unlock(&cookie->stores_lock);
867 spin_unlock(&object->lock);
868 spin_unlock(&cookie->lock);
869 radix_tree_preload_end();
871 fscache_stat(&fscache_n_stores_ok);
876 spin_lock(&cookie->stores_lock);
877 radix_tree_delete(&cookie->stores, page->index);
878 spin_unlock(&cookie->stores_lock);
879 page_cache_release(page);
884 spin_unlock(&object->lock);
886 spin_unlock(&cookie->lock);
887 radix_tree_preload_end();
889 fscache_stat(&fscache_n_stores_nobufs);
890 _leave(" = -ENOBUFS");
896 fscache_stat(&fscache_n_stores_oom);
897 _leave(" = -ENOMEM");
900 EXPORT_SYMBOL(__fscache_write_page);
903 * remove a page from the cache
905 void __fscache_uncache_page(struct fscache_cookie *cookie, struct page *page)
907 struct fscache_object *object;
911 ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
912 ASSERTCMP(page, !=, NULL);
914 fscache_stat(&fscache_n_uncaches);
916 /* cache withdrawal may beat us to it */
917 if (!PageFsCache(page))
921 spin_lock(&cookie->lock);
923 if (hlist_empty(&cookie->backing_objects)) {
924 ClearPageFsCache(page);
928 object = hlist_entry(cookie->backing_objects.first,
929 struct fscache_object, cookie_link);
931 /* there might now be stuff on disk we could read */
932 clear_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
934 /* only invoke the cache backend if we managed to mark the page
935 * uncached here; this deals with synchronisation vs withdrawal */
936 if (TestClearPageFsCache(page) &&
937 object->cache->ops->uncache_page) {
938 /* the cache backend releases the cookie lock */
939 fscache_stat(&fscache_n_cop_uncache_page);
940 object->cache->ops->uncache_page(object, page);
941 fscache_stat_d(&fscache_n_cop_uncache_page);
946 spin_unlock(&cookie->lock);
950 EXPORT_SYMBOL(__fscache_uncache_page);
953 * fscache_mark_pages_cached - Mark pages as being cached
954 * @op: The retrieval op pages are being marked for
955 * @pagevec: The pages to be marked
957 * Mark a bunch of netfs pages as being cached. After this is called,
958 * the netfs must call fscache_uncache_page() to remove the mark.
960 void fscache_mark_pages_cached(struct fscache_retrieval *op,
961 struct pagevec *pagevec)
963 struct fscache_cookie *cookie = op->op.object->cookie;
966 #ifdef CONFIG_FSCACHE_STATS
967 atomic_add(pagevec->nr, &fscache_n_marks);
970 for (loop = 0; loop < pagevec->nr; loop++) {
971 struct page *page = pagevec->pages[loop];
973 _debug("- mark %p{%lx}", page, page->index);
974 if (TestSetPageFsCache(page)) {
975 static bool once_only;
978 printk(KERN_WARNING "FS-Cache:"
979 " Cookie type %s marked page %lx"
981 cookie->def->name, page->index);
986 if (cookie->def->mark_pages_cached)
987 cookie->def->mark_pages_cached(cookie->netfs_data,
988 op->mapping, pagevec);
989 pagevec_reinit(pagevec);
991 EXPORT_SYMBOL(fscache_mark_pages_cached);