diff options
Diffstat (limited to 'fs/fscache/page.c')
| -rw-r--r-- | fs/fscache/page.c | 816 | 
1 files changed, 816 insertions, 0 deletions
diff --git a/fs/fscache/page.c b/fs/fscache/page.c new file mode 100644 index 00000000000..2568e0eb644 --- /dev/null +++ b/fs/fscache/page.c @@ -0,0 +1,816 @@ +/* Cache page management and data I/O routines + * + * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#define FSCACHE_DEBUG_LEVEL PAGE +#include <linux/module.h> +#include <linux/fscache-cache.h> +#include <linux/buffer_head.h> +#include <linux/pagevec.h> +#include "internal.h" + +/* + * check to see if a page is being written to the cache + */ +bool __fscache_check_page_write(struct fscache_cookie *cookie, struct page *page) +{ +	void *val; + +	rcu_read_lock(); +	val = radix_tree_lookup(&cookie->stores, page->index); +	rcu_read_unlock(); + +	return val != NULL; +} +EXPORT_SYMBOL(__fscache_check_page_write); + +/* + * wait for a page to finish being written to the cache + */ +void __fscache_wait_on_page_write(struct fscache_cookie *cookie, struct page *page) +{ +	wait_queue_head_t *wq = bit_waitqueue(&cookie->flags, 0); + +	wait_event(*wq, !__fscache_check_page_write(cookie, page)); +} +EXPORT_SYMBOL(__fscache_wait_on_page_write); + +/* + * note that a page has finished being written to the cache + */ +static void fscache_end_page_write(struct fscache_cookie *cookie, struct page *page) +{ +	struct page *xpage; + +	spin_lock(&cookie->lock); +	xpage = radix_tree_delete(&cookie->stores, page->index); +	spin_unlock(&cookie->lock); +	ASSERT(xpage != NULL); + +	wake_up_bit(&cookie->flags, 0); +} + +/* + * actually apply the changed attributes to a cache object + */ +static void fscache_attr_changed_op(struct fscache_operation *op) +{ +	struct fscache_object *object = op->object; + +	_enter("{OBJ%x OP%x}", object->debug_id, op->debug_id); + +	fscache_stat(&fscache_n_attr_changed_calls); + +	if (fscache_object_is_active(object) && +	    object->cache->ops->attr_changed(object) < 0) +		fscache_abort_object(object); + +	_leave(""); +} + +/* + * notification that the attributes on an object have changed + */ +int __fscache_attr_changed(struct fscache_cookie *cookie) +{ +	struct fscache_operation *op; +	struct fscache_object *object; + +	_enter("%p", cookie); + +	ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); + +	fscache_stat(&fscache_n_attr_changed); + +	op = kzalloc(sizeof(*op), GFP_KERNEL); +	if (!op) { +		fscache_stat(&fscache_n_attr_changed_nomem); +		_leave(" = -ENOMEM"); +		return -ENOMEM; +	} + +	fscache_operation_init(op, NULL); +	fscache_operation_init_slow(op, fscache_attr_changed_op); +	op->flags = FSCACHE_OP_SLOW | (1 << FSCACHE_OP_EXCLUSIVE); + +	spin_lock(&cookie->lock); + +	if (hlist_empty(&cookie->backing_objects)) +		goto nobufs; +	object = hlist_entry(cookie->backing_objects.first, +			     struct fscache_object, cookie_link); + +	if (fscache_submit_exclusive_op(object, op) < 0) +		goto nobufs; +	spin_unlock(&cookie->lock); +	fscache_stat(&fscache_n_attr_changed_ok); +	fscache_put_operation(op); +	_leave(" = 0"); +	return 0; + +nobufs: +	spin_unlock(&cookie->lock); +	kfree(op); +	fscache_stat(&fscache_n_attr_changed_nobufs); +	_leave(" = %d", -ENOBUFS); +	return -ENOBUFS; +} +EXPORT_SYMBOL(__fscache_attr_changed); + +/* + * handle secondary execution given to a retrieval op on behalf of the + * cache + */ +static void fscache_retrieval_work(struct work_struct *work) +{ +	struct fscache_retrieval *op = +		container_of(work, struct fscache_retrieval, op.fast_work); +	unsigned long start; + +	_enter("{OP%x}", op->op.debug_id); + +	start = jiffies; +	op->op.processor(&op->op); +	fscache_hist(fscache_ops_histogram, start); +	fscache_put_operation(&op->op); +} + +/* + * release a retrieval op reference + */ +static void fscache_release_retrieval_op(struct fscache_operation *_op) +{ +	struct fscache_retrieval *op = +		container_of(_op, struct fscache_retrieval, op); + +	_enter("{OP%x}", op->op.debug_id); + +	fscache_hist(fscache_retrieval_histogram, op->start_time); +	if (op->context) +		fscache_put_context(op->op.object->cookie, op->context); + +	_leave(""); +} + +/* + * allocate a retrieval op + */ +static struct fscache_retrieval *fscache_alloc_retrieval( +	struct address_space *mapping, +	fscache_rw_complete_t end_io_func, +	void *context) +{ +	struct fscache_retrieval *op; + +	/* allocate a retrieval operation and attempt to submit it */ +	op = kzalloc(sizeof(*op), GFP_NOIO); +	if (!op) { +		fscache_stat(&fscache_n_retrievals_nomem); +		return NULL; +	} + +	fscache_operation_init(&op->op, fscache_release_retrieval_op); +	op->op.flags	= FSCACHE_OP_MYTHREAD | (1 << FSCACHE_OP_WAITING); +	op->mapping	= mapping; +	op->end_io_func	= end_io_func; +	op->context	= context; +	op->start_time	= jiffies; +	INIT_WORK(&op->op.fast_work, fscache_retrieval_work); +	INIT_LIST_HEAD(&op->to_do); +	return op; +} + +/* + * wait for a deferred lookup to complete + */ +static int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie) +{ +	unsigned long jif; + +	_enter(""); + +	if (!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) { +		_leave(" = 0 [imm]"); +		return 0; +	} + +	fscache_stat(&fscache_n_retrievals_wait); + +	jif = jiffies; +	if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP, +			fscache_wait_bit_interruptible, +			TASK_INTERRUPTIBLE) != 0) { +		fscache_stat(&fscache_n_retrievals_intr); +		_leave(" = -ERESTARTSYS"); +		return -ERESTARTSYS; +	} + +	ASSERT(!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)); + +	smp_rmb(); +	fscache_hist(fscache_retrieval_delay_histogram, jif); +	_leave(" = 0 [dly]"); +	return 0; +} + +/* + * read a page from the cache or allocate a block in which to store it + * - we return: + *   -ENOMEM	- out of memory, nothing done + *   -ERESTARTSYS - interrupted + *   -ENOBUFS	- no backing object available in which to cache the block + *   -ENODATA	- no data available in the backing object for this block + *   0		- dispatched a read - it'll call end_io_func() when finished + */ +int __fscache_read_or_alloc_page(struct fscache_cookie *cookie, +				 struct page *page, +				 fscache_rw_complete_t end_io_func, +				 void *context, +				 gfp_t gfp) +{ +	struct fscache_retrieval *op; +	struct fscache_object *object; +	int ret; + +	_enter("%p,%p,,,", cookie, page); + +	fscache_stat(&fscache_n_retrievals); + +	if (hlist_empty(&cookie->backing_objects)) +		goto nobufs; + +	ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); +	ASSERTCMP(page, !=, NULL); + +	if (fscache_wait_for_deferred_lookup(cookie) < 0) +		return -ERESTARTSYS; + +	op = fscache_alloc_retrieval(page->mapping, end_io_func, context); +	if (!op) { +		_leave(" = -ENOMEM"); +		return -ENOMEM; +	} + +	spin_lock(&cookie->lock); + +	if (hlist_empty(&cookie->backing_objects)) +		goto nobufs_unlock; +	object = hlist_entry(cookie->backing_objects.first, +			     struct fscache_object, cookie_link); + +	ASSERTCMP(object->state, >, FSCACHE_OBJECT_LOOKING_UP); + +	if (fscache_submit_op(object, &op->op) < 0) +		goto nobufs_unlock; +	spin_unlock(&cookie->lock); + +	fscache_stat(&fscache_n_retrieval_ops); + +	/* pin the netfs read context in case we need to do the actual netfs +	 * read because we've encountered a cache read failure */ +	fscache_get_context(object->cookie, op->context); + +	/* we wait for the operation to become active, and then process it +	 * *here*, in this thread, and not in the thread pool */ +	if (test_bit(FSCACHE_OP_WAITING, &op->op.flags)) { +		_debug(">>> WT"); +		fscache_stat(&fscache_n_retrieval_op_waits); +		wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING, +			    fscache_wait_bit, TASK_UNINTERRUPTIBLE); +		_debug("<<< GO"); +	} + +	/* ask the cache to honour the operation */ +	if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) { +		ret = object->cache->ops->allocate_page(op, page, gfp); +		if (ret == 0) +			ret = -ENODATA; +	} else { +		ret = object->cache->ops->read_or_alloc_page(op, page, gfp); +	} + +	if (ret == -ENOMEM) +		fscache_stat(&fscache_n_retrievals_nomem); +	else if (ret == -ERESTARTSYS) +		fscache_stat(&fscache_n_retrievals_intr); +	else if (ret == -ENODATA) +		fscache_stat(&fscache_n_retrievals_nodata); +	else if (ret < 0) +		fscache_stat(&fscache_n_retrievals_nobufs); +	else +		fscache_stat(&fscache_n_retrievals_ok); + +	fscache_put_retrieval(op); +	_leave(" = %d", ret); +	return ret; + +nobufs_unlock: +	spin_unlock(&cookie->lock); +	kfree(op); +nobufs: +	fscache_stat(&fscache_n_retrievals_nobufs); +	_leave(" = -ENOBUFS"); +	return -ENOBUFS; +} +EXPORT_SYMBOL(__fscache_read_or_alloc_page); + +/* + * read a list of page from the cache or allocate a block in which to store + * them + * - we return: + *   -ENOMEM	- out of memory, some pages may be being read + *   -ERESTARTSYS - interrupted, some pages may be being read + *   -ENOBUFS	- no backing object or space available in which to cache any + *                pages not being read + *   -ENODATA	- no data available in the backing object for some or all of + *                the pages + *   0		- dispatched a read on all pages + * + * end_io_func() will be called for each page read from the cache as it is + * finishes being read + * + * any pages for which a read is dispatched will be removed from pages and + * nr_pages + */ +int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie, +				  struct address_space *mapping, +				  struct list_head *pages, +				  unsigned *nr_pages, +				  fscache_rw_complete_t end_io_func, +				  void *context, +				  gfp_t gfp) +{ +	fscache_pages_retrieval_func_t func; +	struct fscache_retrieval *op; +	struct fscache_object *object; +	int ret; + +	_enter("%p,,%d,,,", cookie, *nr_pages); + +	fscache_stat(&fscache_n_retrievals); + +	if (hlist_empty(&cookie->backing_objects)) +		goto nobufs; + +	ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); +	ASSERTCMP(*nr_pages, >, 0); +	ASSERT(!list_empty(pages)); + +	if (fscache_wait_for_deferred_lookup(cookie) < 0) +		return -ERESTARTSYS; + +	op = fscache_alloc_retrieval(mapping, end_io_func, context); +	if (!op) +		return -ENOMEM; + +	spin_lock(&cookie->lock); + +	if (hlist_empty(&cookie->backing_objects)) +		goto nobufs_unlock; +	object = hlist_entry(cookie->backing_objects.first, +			     struct fscache_object, cookie_link); + +	if (fscache_submit_op(object, &op->op) < 0) +		goto nobufs_unlock; +	spin_unlock(&cookie->lock); + +	fscache_stat(&fscache_n_retrieval_ops); + +	/* pin the netfs read context in case we need to do the actual netfs +	 * read because we've encountered a cache read failure */ +	fscache_get_context(object->cookie, op->context); + +	/* we wait for the operation to become active, and then process it +	 * *here*, in this thread, and not in the thread pool */ +	if (test_bit(FSCACHE_OP_WAITING, &op->op.flags)) { +		_debug(">>> WT"); +		fscache_stat(&fscache_n_retrieval_op_waits); +		wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING, +			    fscache_wait_bit, TASK_UNINTERRUPTIBLE); +		_debug("<<< GO"); +	} + +	/* ask the cache to honour the operation */ +	if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) +		func = object->cache->ops->allocate_pages; +	else +		func = object->cache->ops->read_or_alloc_pages; +	ret = func(op, pages, nr_pages, gfp); + +	if (ret == -ENOMEM) +		fscache_stat(&fscache_n_retrievals_nomem); +	else if (ret == -ERESTARTSYS) +		fscache_stat(&fscache_n_retrievals_intr); +	else if (ret == -ENODATA) +		fscache_stat(&fscache_n_retrievals_nodata); +	else if (ret < 0) +		fscache_stat(&fscache_n_retrievals_nobufs); +	else +		fscache_stat(&fscache_n_retrievals_ok); + +	fscache_put_retrieval(op); +	_leave(" = %d", ret); +	return ret; + +nobufs_unlock: +	spin_unlock(&cookie->lock); +	kfree(op); +nobufs: +	fscache_stat(&fscache_n_retrievals_nobufs); +	_leave(" = -ENOBUFS"); +	return -ENOBUFS; +} +EXPORT_SYMBOL(__fscache_read_or_alloc_pages); + +/* + * allocate a block in the cache on which to store a page + * - we return: + *   -ENOMEM	- out of memory, nothing done + *   -ERESTARTSYS - interrupted + *   -ENOBUFS	- no backing object available in which to cache the block + *   0		- block allocated + */ +int __fscache_alloc_page(struct fscache_cookie *cookie, +			 struct page *page, +			 gfp_t gfp) +{ +	struct fscache_retrieval *op; +	struct fscache_object *object; +	int ret; + +	_enter("%p,%p,,,", cookie, page); + +	fscache_stat(&fscache_n_allocs); + +	if (hlist_empty(&cookie->backing_objects)) +		goto nobufs; + +	ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); +	ASSERTCMP(page, !=, NULL); + +	if (fscache_wait_for_deferred_lookup(cookie) < 0) +		return -ERESTARTSYS; + +	op = fscache_alloc_retrieval(page->mapping, NULL, NULL); +	if (!op) +		return -ENOMEM; + +	spin_lock(&cookie->lock); + +	if (hlist_empty(&cookie->backing_objects)) +		goto nobufs_unlock; +	object = hlist_entry(cookie->backing_objects.first, +			     struct fscache_object, cookie_link); + +	if (fscache_submit_op(object, &op->op) < 0) +		goto nobufs_unlock; +	spin_unlock(&cookie->lock); + +	fscache_stat(&fscache_n_alloc_ops); + +	if (test_bit(FSCACHE_OP_WAITING, &op->op.flags)) { +		_debug(">>> WT"); +		fscache_stat(&fscache_n_alloc_op_waits); +		wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING, +			    fscache_wait_bit, TASK_UNINTERRUPTIBLE); +		_debug("<<< GO"); +	} + +	/* ask the cache to honour the operation */ +	ret = object->cache->ops->allocate_page(op, page, gfp); + +	if (ret < 0) +		fscache_stat(&fscache_n_allocs_nobufs); +	else +		fscache_stat(&fscache_n_allocs_ok); + +	fscache_put_retrieval(op); +	_leave(" = %d", ret); +	return ret; + +nobufs_unlock: +	spin_unlock(&cookie->lock); +	kfree(op); +nobufs: +	fscache_stat(&fscache_n_allocs_nobufs); +	_leave(" = -ENOBUFS"); +	return -ENOBUFS; +} +EXPORT_SYMBOL(__fscache_alloc_page); + +/* + * release a write op reference + */ +static void fscache_release_write_op(struct fscache_operation *_op) +{ +	_enter("{OP%x}", _op->debug_id); +} + +/* + * perform the background storage of a page into the cache + */ +static void fscache_write_op(struct fscache_operation *_op) +{ +	struct fscache_storage *op = +		container_of(_op, struct fscache_storage, op); +	struct fscache_object *object = op->op.object; +	struct fscache_cookie *cookie = object->cookie; +	struct page *page; +	unsigned n; +	void *results[1]; +	int ret; + +	_enter("{OP%x,%d}", op->op.debug_id, atomic_read(&op->op.usage)); + +	spin_lock(&cookie->lock); +	spin_lock(&object->lock); + +	if (!fscache_object_is_active(object)) { +		spin_unlock(&object->lock); +		spin_unlock(&cookie->lock); +		_leave(""); +		return; +	} + +	fscache_stat(&fscache_n_store_calls); + +	/* find a page to store */ +	page = NULL; +	n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, 1, +				       FSCACHE_COOKIE_PENDING_TAG); +	if (n != 1) +		goto superseded; +	page = results[0]; +	_debug("gang %d [%lx]", n, page->index); +	if (page->index > op->store_limit) +		goto superseded; + +	radix_tree_tag_clear(&cookie->stores, page->index, +			     FSCACHE_COOKIE_PENDING_TAG); + +	spin_unlock(&object->lock); +	spin_unlock(&cookie->lock); + +	if (page) { +		ret = object->cache->ops->write_page(op, page); +		fscache_end_page_write(cookie, page); +		page_cache_release(page); +		if (ret < 0) +			fscache_abort_object(object); +		else +			fscache_enqueue_operation(&op->op); +	} + +	_leave(""); +	return; + +superseded: +	/* this writer is going away and there aren't any more things to +	 * write */ +	_debug("cease"); +	clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags); +	spin_unlock(&object->lock); +	spin_unlock(&cookie->lock); +	_leave(""); +} + +/* + * request a page be stored in the cache + * - returns: + *   -ENOMEM	- out of memory, nothing done + *   -ENOBUFS	- no backing object available in which to cache the page + *   0		- dispatched a write - it'll call end_io_func() when finished + * + * if the cookie still has a backing object at this point, that object can be + * in one of a few states with respect to storage processing: + * + *  (1) negative lookup, object not yet created (FSCACHE_COOKIE_CREATING is + *      set) + * + *	(a) no writes yet (set FSCACHE_COOKIE_PENDING_FILL and queue deferred + *	    fill op) + * + *	(b) writes deferred till post-creation (mark page for writing and + *	    return immediately) + * + *  (2) negative lookup, object created, initial fill being made from netfs + *      (FSCACHE_COOKIE_INITIAL_FILL is set) + * + *	(a) fill point not yet reached this page (mark page for writing and + *          return) + * + *	(b) fill point passed this page (queue op to store this page) + * + *  (3) object extant (queue op to store this page) + * + * any other state is invalid + */ +int __fscache_write_page(struct fscache_cookie *cookie, +			 struct page *page, +			 gfp_t gfp) +{ +	struct fscache_storage *op; +	struct fscache_object *object; +	int ret; + +	_enter("%p,%x,", cookie, (u32) page->flags); + +	ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); +	ASSERT(PageFsCache(page)); + +	fscache_stat(&fscache_n_stores); + +	op = kzalloc(sizeof(*op), GFP_NOIO); +	if (!op) +		goto nomem; + +	fscache_operation_init(&op->op, fscache_release_write_op); +	fscache_operation_init_slow(&op->op, fscache_write_op); +	op->op.flags = FSCACHE_OP_SLOW | (1 << FSCACHE_OP_WAITING); + +	ret = radix_tree_preload(gfp & ~__GFP_HIGHMEM); +	if (ret < 0) +		goto nomem_free; + +	ret = -ENOBUFS; +	spin_lock(&cookie->lock); + +	if (hlist_empty(&cookie->backing_objects)) +		goto nobufs; +	object = hlist_entry(cookie->backing_objects.first, +			     struct fscache_object, cookie_link); +	if (test_bit(FSCACHE_IOERROR, &object->cache->flags)) +		goto nobufs; + +	/* add the page to the pending-storage radix tree on the backing +	 * object */ +	spin_lock(&object->lock); + +	_debug("store limit %llx", (unsigned long long) object->store_limit); + +	ret = radix_tree_insert(&cookie->stores, page->index, page); +	if (ret < 0) { +		if (ret == -EEXIST) +			goto already_queued; +		_debug("insert failed %d", ret); +		goto nobufs_unlock_obj; +	} + +	radix_tree_tag_set(&cookie->stores, page->index, +			   FSCACHE_COOKIE_PENDING_TAG); +	page_cache_get(page); + +	/* we only want one writer at a time, but we do need to queue new +	 * writers after exclusive ops */ +	if (test_and_set_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags)) +		goto already_pending; + +	spin_unlock(&object->lock); + +	op->op.debug_id	= atomic_inc_return(&fscache_op_debug_id); +	op->store_limit = object->store_limit; + +	if (fscache_submit_op(object, &op->op) < 0) +		goto submit_failed; + +	spin_unlock(&cookie->lock); +	radix_tree_preload_end(); +	fscache_stat(&fscache_n_store_ops); +	fscache_stat(&fscache_n_stores_ok); + +	/* the slow work queue now carries its own ref on the object */ +	fscache_put_operation(&op->op); +	_leave(" = 0"); +	return 0; + +already_queued: +	fscache_stat(&fscache_n_stores_again); +already_pending: +	spin_unlock(&object->lock); +	spin_unlock(&cookie->lock); +	radix_tree_preload_end(); +	kfree(op); +	fscache_stat(&fscache_n_stores_ok); +	_leave(" = 0"); +	return 0; + +submit_failed: +	radix_tree_delete(&cookie->stores, page->index); +	page_cache_release(page); +	ret = -ENOBUFS; +	goto nobufs; + +nobufs_unlock_obj: +	spin_unlock(&object->lock); +nobufs: +	spin_unlock(&cookie->lock); +	radix_tree_preload_end(); +	kfree(op); +	fscache_stat(&fscache_n_stores_nobufs); +	_leave(" = -ENOBUFS"); +	return -ENOBUFS; + +nomem_free: +	kfree(op); +nomem: +	fscache_stat(&fscache_n_stores_oom); +	_leave(" = -ENOMEM"); +	return -ENOMEM; +} +EXPORT_SYMBOL(__fscache_write_page); + +/* + * remove a page from the cache + */ +void __fscache_uncache_page(struct fscache_cookie *cookie, struct page *page) +{ +	struct fscache_object *object; + +	_enter(",%p", page); + +	ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); +	ASSERTCMP(page, !=, NULL); + +	fscache_stat(&fscache_n_uncaches); + +	/* cache withdrawal may beat us to it */ +	if (!PageFsCache(page)) +		goto done; + +	/* get the object */ +	spin_lock(&cookie->lock); + +	if (hlist_empty(&cookie->backing_objects)) { +		ClearPageFsCache(page); +		goto done_unlock; +	} + +	object = hlist_entry(cookie->backing_objects.first, +			     struct fscache_object, cookie_link); + +	/* there might now be stuff on disk we could read */ +	clear_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); + +	/* only invoke the cache backend if we managed to mark the page +	 * uncached here; this deals with synchronisation vs withdrawal */ +	if (TestClearPageFsCache(page) && +	    object->cache->ops->uncache_page) { +		/* the cache backend releases the cookie lock */ +		object->cache->ops->uncache_page(object, page); +		goto done; +	} + +done_unlock: +	spin_unlock(&cookie->lock); +done: +	_leave(""); +} +EXPORT_SYMBOL(__fscache_uncache_page); + +/** + * fscache_mark_pages_cached - Mark pages as being cached + * @op: The retrieval op pages are being marked for + * @pagevec: The pages to be marked + * + * Mark a bunch of netfs pages as being cached.  After this is called, + * the netfs must call fscache_uncache_page() to remove the mark. + */ +void fscache_mark_pages_cached(struct fscache_retrieval *op, +			       struct pagevec *pagevec) +{ +	struct fscache_cookie *cookie = op->op.object->cookie; +	unsigned long loop; + +#ifdef CONFIG_FSCACHE_STATS +	atomic_add(pagevec->nr, &fscache_n_marks); +#endif + +	for (loop = 0; loop < pagevec->nr; loop++) { +		struct page *page = pagevec->pages[loop]; + +		_debug("- mark %p{%lx}", page, page->index); +		if (TestSetPageFsCache(page)) { +			static bool once_only; +			if (!once_only) { +				once_only = true; +				printk(KERN_WARNING "FS-Cache:" +				       " Cookie type %s marked page %lx" +				       " multiple times\n", +				       cookie->def->name, page->index); +			} +		} +	} + +	if (cookie->def->mark_pages_cached) +		cookie->def->mark_pages_cached(cookie->netfs_data, +					       op->mapping, pagevec); +	pagevec_reinit(pagevec); +} +EXPORT_SYMBOL(fscache_mark_pages_cached);  |