summaryrefslogtreecommitdiff
path: root/fs/fscache/page.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/fscache/page.c')
-rw-r--r--fs/fscache/page.c1242
1 files changed, 0 insertions, 1242 deletions
diff --git a/fs/fscache/page.c b/fs/fscache/page.c
deleted file mode 100644
index 27df94ef0e0b..000000000000
--- a/fs/fscache/page.c
+++ /dev/null
@@ -1,1242 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/* 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)
- */
-
-#define FSCACHE_DEBUG_LEVEL PAGE
-#include <linux/module.h>
-#include <linux/fscache-cache.h>
-#include <linux/buffer_head.h>
-#include <linux/pagevec.h>
-#include <linux/slab.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();
- trace_fscache_check_page(cookie, page, val, 0);
-
- 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);
-
- trace_fscache_page(cookie, page, fscache_page_write_wait);
-
- wait_event(*wq, !__fscache_check_page_write(cookie, page));
-}
-EXPORT_SYMBOL(__fscache_wait_on_page_write);
-
-/*
- * wait for a page to finish being written to the cache. Put a timeout here
- * since we might be called recursively via parent fs.
- */
-static
-bool release_page_wait_timeout(struct fscache_cookie *cookie, struct page *page)
-{
- wait_queue_head_t *wq = bit_waitqueue(&cookie->flags, 0);
-
- return wait_event_timeout(*wq, !__fscache_check_page_write(cookie, page),
- HZ);
-}
-
-/*
- * decide whether a page can be released, possibly by cancelling a store to it
- * - we're allowed to sleep if __GFP_DIRECT_RECLAIM is flagged
- */
-bool __fscache_maybe_release_page(struct fscache_cookie *cookie,
- struct page *page,
- gfp_t gfp)
-{
- struct page *xpage;
- void *val;
-
- _enter("%p,%p,%x", cookie, page, gfp);
-
- trace_fscache_page(cookie, page, fscache_page_maybe_release);
-
-try_again:
- rcu_read_lock();
- val = radix_tree_lookup(&cookie->stores, page->index);
- if (!val) {
- rcu_read_unlock();
- fscache_stat(&fscache_n_store_vmscan_not_storing);
- __fscache_uncache_page(cookie, page);
- return true;
- }
-
- /* see if the page is actually undergoing storage - if so we can't get
- * rid of it till the cache has finished with it */
- if (radix_tree_tag_get(&cookie->stores, page->index,
- FSCACHE_COOKIE_STORING_TAG)) {
- rcu_read_unlock();
- goto page_busy;
- }
-
- /* the page is pending storage, so we attempt to cancel the store and
- * discard the store request so that the page can be reclaimed */
- spin_lock(&cookie->stores_lock);
- rcu_read_unlock();
-
- if (radix_tree_tag_get(&cookie->stores, page->index,
- FSCACHE_COOKIE_STORING_TAG)) {
- /* the page started to undergo storage whilst we were looking,
- * so now we can only wait or return */
- spin_unlock(&cookie->stores_lock);
- goto page_busy;
- }
-
- xpage = radix_tree_delete(&cookie->stores, page->index);
- trace_fscache_page(cookie, page, fscache_page_radix_delete);
- spin_unlock(&cookie->stores_lock);
-
- if (xpage) {
- fscache_stat(&fscache_n_store_vmscan_cancelled);
- fscache_stat(&fscache_n_store_radix_deletes);
- ASSERTCMP(xpage, ==, page);
- } else {
- fscache_stat(&fscache_n_store_vmscan_gone);
- }
-
- wake_up_bit(&cookie->flags, 0);
- trace_fscache_wake_cookie(cookie);
- if (xpage)
- put_page(xpage);
- __fscache_uncache_page(cookie, page);
- return true;
-
-page_busy:
- /* We will wait here if we're allowed to, but that could deadlock the
- * allocator as the work threads writing to the cache may all end up
- * sleeping on memory allocation, so we may need to impose a timeout
- * too. */
- if (!(gfp & __GFP_DIRECT_RECLAIM) || !(gfp & __GFP_FS)) {
- fscache_stat(&fscache_n_store_vmscan_busy);
- return false;
- }
-
- fscache_stat(&fscache_n_store_vmscan_wait);
- if (!release_page_wait_timeout(cookie, page))
- _debug("fscache writeout timeout page: %p{%lx}",
- page, page->index);
-
- gfp &= ~__GFP_DIRECT_RECLAIM;
- goto try_again;
-}
-EXPORT_SYMBOL(__fscache_maybe_release_page);
-
-/*
- * note that a page has finished being written to the cache
- */
-static void fscache_end_page_write(struct fscache_object *object,
- struct page *page)
-{
- struct fscache_cookie *cookie;
- struct page *xpage = NULL, *val;
-
- spin_lock(&object->lock);
- cookie = object->cookie;
- if (cookie) {
- /* delete the page from the tree if it is now no longer
- * pending */
- spin_lock(&cookie->stores_lock);
- radix_tree_tag_clear(&cookie->stores, page->index,
- FSCACHE_COOKIE_STORING_TAG);
- trace_fscache_page(cookie, page, fscache_page_radix_clear_store);
- if (!radix_tree_tag_get(&cookie->stores, page->index,
- FSCACHE_COOKIE_PENDING_TAG)) {
- fscache_stat(&fscache_n_store_radix_deletes);
- xpage = radix_tree_delete(&cookie->stores, page->index);
- trace_fscache_page(cookie, page, fscache_page_radix_delete);
- trace_fscache_page(cookie, page, fscache_page_write_end);
-
- val = radix_tree_lookup(&cookie->stores, page->index);
- trace_fscache_check_page(cookie, page, val, 1);
- } else {
- trace_fscache_page(cookie, page, fscache_page_write_end_pend);
- }
- spin_unlock(&cookie->stores_lock);
- wake_up_bit(&cookie->flags, 0);
- trace_fscache_wake_cookie(cookie);
- } else {
- trace_fscache_page(cookie, page, fscache_page_write_end_noc);
- }
- spin_unlock(&object->lock);
- if (xpage)
- put_page(xpage);
-}
-
-/*
- * 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;
- int ret;
-
- _enter("{OBJ%x OP%x}", object->debug_id, op->debug_id);
-
- fscache_stat(&fscache_n_attr_changed_calls);
-
- if (fscache_object_is_active(object)) {
- fscache_stat(&fscache_n_cop_attr_changed);
- ret = object->cache->ops->attr_changed(object);
- fscache_stat_d(&fscache_n_cop_attr_changed);
- if (ret < 0)
- fscache_abort_object(object);
- fscache_op_complete(op, ret < 0);
- } else {
- fscache_op_complete(op, true);
- }
-
- _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;
- bool wake_cookie = false;
-
- _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(cookie, op, fscache_attr_changed_op, NULL, NULL);
- trace_fscache_page_op(cookie, NULL, op, fscache_page_op_attr_changed);
- op->flags = FSCACHE_OP_ASYNC |
- (1 << FSCACHE_OP_EXCLUSIVE) |
- (1 << FSCACHE_OP_UNUSE_COOKIE);
-
- spin_lock(&cookie->lock);
-
- if (!fscache_cookie_enabled(cookie) ||
- hlist_empty(&cookie->backing_objects))
- goto nobufs;
- object = hlist_entry(cookie->backing_objects.first,
- struct fscache_object, cookie_link);
-
- __fscache_use_cookie(cookie);
- if (fscache_submit_exclusive_op(object, op) < 0)
- goto nobufs_dec;
- spin_unlock(&cookie->lock);
- fscache_stat(&fscache_n_attr_changed_ok);
- fscache_put_operation(op);
- _leave(" = 0");
- return 0;
-
-nobufs_dec:
- wake_cookie = __fscache_unuse_cookie(cookie);
-nobufs:
- spin_unlock(&cookie->lock);
- fscache_put_operation(op);
- if (wake_cookie)
- __fscache_wake_unused_cookie(cookie);
- fscache_stat(&fscache_n_attr_changed_nobufs);
- _leave(" = %d", -ENOBUFS);
- return -ENOBUFS;
-}
-EXPORT_SYMBOL(__fscache_attr_changed);
-
-/*
- * Handle cancellation of a pending retrieval op
- */
-static void fscache_do_cancel_retrieval(struct fscache_operation *_op)
-{
- struct fscache_retrieval *op =
- container_of(_op, struct fscache_retrieval, op);
-
- atomic_set(&op->n_pages, 0);
-}
-
-/*
- * 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);
-
- ASSERTIFCMP(op->op.state != FSCACHE_OP_ST_INITIALISED,
- atomic_read(&op->n_pages), ==, 0);
-
- if (op->context)
- fscache_put_context(op->cookie, op->context);
-
- _leave("");
-}
-
-/*
- * allocate a retrieval op
- */
-struct fscache_retrieval *fscache_alloc_retrieval(
- struct fscache_cookie *cookie,
- 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(cookie, &op->op, NULL,
- fscache_do_cancel_retrieval,
- fscache_release_retrieval_op);
- op->op.flags = FSCACHE_OP_MYTHREAD |
- (1UL << FSCACHE_OP_WAITING) |
- (1UL << FSCACHE_OP_UNUSE_COOKIE);
- op->cookie = cookie;
- op->mapping = mapping;
- op->end_io_func = end_io_func;
- op->context = context;
- INIT_LIST_HEAD(&op->to_do);
-
- /* Pin the netfs read context in case we need to do the actual netfs
- * read because we've encountered a cache read failure.
- */
- if (context)
- fscache_get_context(op->cookie, context);
- return op;
-}
-
-/*
- * wait for a deferred lookup to complete
- */
-int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)
-{
- _enter("");
-
- if (!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) {
- _leave(" = 0 [imm]");
- return 0;
- }
-
- fscache_stat(&fscache_n_retrievals_wait);
-
- if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP,
- TASK_INTERRUPTIBLE) != 0) {
- fscache_stat(&fscache_n_retrievals_intr);
- _leave(" = -ERESTARTSYS");
- return -ERESTARTSYS;
- }
-
- ASSERT(!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags));
-
- smp_rmb();
- _leave(" = 0 [dly]");
- return 0;
-}
-
-/*
- * wait for an object to become active (or dead)
- */
-int fscache_wait_for_operation_activation(struct fscache_object *object,
- struct fscache_operation *op,
- atomic_t *stat_op_waits,
- atomic_t *stat_object_dead)
-{
- int ret;
-
- if (!test_bit(FSCACHE_OP_WAITING, &op->flags))
- goto check_if_dead;
-
- _debug(">>> WT");
- if (stat_op_waits)
- fscache_stat(stat_op_waits);
- if (wait_on_bit(&op->flags, FSCACHE_OP_WAITING,
- TASK_INTERRUPTIBLE) != 0) {
- trace_fscache_op(object->cookie, op, fscache_op_signal);
- ret = fscache_cancel_op(op, false);
- if (ret == 0)
- return -ERESTARTSYS;
-
- /* it's been removed from the pending queue by another party,
- * so we should get to run shortly */
- wait_on_bit(&op->flags, FSCACHE_OP_WAITING,
- TASK_UNINTERRUPTIBLE);
- }
- _debug("<<< GO");
-
-check_if_dead:
- if (op->state == FSCACHE_OP_ST_CANCELLED) {
- if (stat_object_dead)
- fscache_stat(stat_object_dead);
- _leave(" = -ENOBUFS [cancelled]");
- return -ENOBUFS;
- }
- if (unlikely(fscache_object_is_dying(object) ||
- fscache_cache_is_broken(object))) {
- enum fscache_operation_state state = op->state;
- trace_fscache_op(object->cookie, op, fscache_op_signal);
- fscache_cancel_op(op, true);
- if (stat_object_dead)
- fscache_stat(stat_object_dead);
- _leave(" = -ENOBUFS [obj dead %d]", state);
- return -ENOBUFS;
- }
- 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;
- bool wake_cookie = false;
- int ret;
-
- _enter("%p,%p,,,", cookie, page);
-
- fscache_stat(&fscache_n_retrievals);
-
- if (hlist_empty(&cookie->backing_objects))
- goto nobufs;
-
- if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) {
- _leave(" = -ENOBUFS [invalidating]");
- return -ENOBUFS;
- }
-
- 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(cookie, page->mapping,
- end_io_func, context);
- if (!op) {
- _leave(" = -ENOMEM");
- return -ENOMEM;
- }
- atomic_set(&op->n_pages, 1);
- trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_retr_one);
-
- spin_lock(&cookie->lock);
-
- if (!fscache_cookie_enabled(cookie) ||
- hlist_empty(&cookie->backing_objects))
- goto nobufs_unlock;
- object = hlist_entry(cookie->backing_objects.first,
- struct fscache_object, cookie_link);
-
- ASSERT(test_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags));
-
- __fscache_use_cookie(cookie);
- atomic_inc(&object->n_reads);
- __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
-
- if (fscache_submit_op(object, &op->op) < 0)
- goto nobufs_unlock_dec;
- spin_unlock(&cookie->lock);
-
- fscache_stat(&fscache_n_retrieval_ops);
-
- /* we wait for the operation to become active, and then process it
- * *here*, in this thread, and not in the thread pool */
- ret = fscache_wait_for_operation_activation(
- object, &op->op,
- __fscache_stat(&fscache_n_retrieval_op_waits),
- __fscache_stat(&fscache_n_retrievals_object_dead));
- if (ret < 0)
- goto error;
-
- /* ask the cache to honour the operation */
- if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) {
- fscache_stat(&fscache_n_cop_allocate_page);
- ret = object->cache->ops->allocate_page(op, page, gfp);
- fscache_stat_d(&fscache_n_cop_allocate_page);
- if (ret == 0)
- ret = -ENODATA;
- } else {
- fscache_stat(&fscache_n_cop_read_or_alloc_page);
- ret = object->cache->ops->read_or_alloc_page(op, page, gfp);
- fscache_stat_d(&fscache_n_cop_read_or_alloc_page);
- }
-
-error:
- 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_dec:
- atomic_dec(&object->n_reads);
- wake_cookie = __fscache_unuse_cookie(cookie);
-nobufs_unlock:
- spin_unlock(&cookie->lock);
- if (wake_cookie)
- __fscache_wake_unused_cookie(cookie);
- fscache_put_retrieval(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)
-{
- struct fscache_retrieval *op;
- struct fscache_object *object;
- bool wake_cookie = false;
- int ret;
-
- _enter("%p,,%d,,,", cookie, *nr_pages);
-
- fscache_stat(&fscache_n_retrievals);
-
- if (hlist_empty(&cookie->backing_objects))
- goto nobufs;
-
- if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) {
- _leave(" = -ENOBUFS [invalidating]");
- return -ENOBUFS;
- }
-
- 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(cookie, mapping, end_io_func, context);
- if (!op)
- return -ENOMEM;
- atomic_set(&op->n_pages, *nr_pages);
- trace_fscache_page_op(cookie, NULL, &op->op, fscache_page_op_retr_multi);
-
- spin_lock(&cookie->lock);
-
- if (!fscache_cookie_enabled(cookie) ||
- hlist_empty(&cookie->backing_objects))
- goto nobufs_unlock;
- object = hlist_entry(cookie->backing_objects.first,
- struct fscache_object, cookie_link);
-
- __fscache_use_cookie(cookie);
- atomic_inc(&object->n_reads);
- __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
-
- if (fscache_submit_op(object, &op->op) < 0)
- goto nobufs_unlock_dec;
- spin_unlock(&cookie->lock);
-
- fscache_stat(&fscache_n_retrieval_ops);
-
- /* we wait for the operation to become active, and then process it
- * *here*, in this thread, and not in the thread pool */
- ret = fscache_wait_for_operation_activation(
- object, &op->op,
- __fscache_stat(&fscache_n_retrieval_op_waits),
- __fscache_stat(&fscache_n_retrievals_object_dead));
- if (ret < 0)
- goto error;
-
- /* ask the cache to honour the operation */
- if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) {
- fscache_stat(&fscache_n_cop_allocate_pages);
- ret = object->cache->ops->allocate_pages(
- op, pages, nr_pages, gfp);
- fscache_stat_d(&fscache_n_cop_allocate_pages);
- } else {
- fscache_stat(&fscache_n_cop_read_or_alloc_pages);
- ret = object->cache->ops->read_or_alloc_pages(
- op, pages, nr_pages, gfp);
- fscache_stat_d(&fscache_n_cop_read_or_alloc_pages);
- }
-
-error:
- 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_dec:
- atomic_dec(&object->n_reads);
- wake_cookie = __fscache_unuse_cookie(cookie);
-nobufs_unlock:
- spin_unlock(&cookie->lock);
- fscache_put_retrieval(op);
- if (wake_cookie)
- __fscache_wake_unused_cookie(cookie);
-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;
- bool wake_cookie = false;
- 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 (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) {
- _leave(" = -ENOBUFS [invalidating]");
- return -ENOBUFS;
- }
-
- if (fscache_wait_for_deferred_lookup(cookie) < 0)
- return -ERESTARTSYS;
-
- op = fscache_alloc_retrieval(cookie, page->mapping, NULL, NULL);
- if (!op)
- return -ENOMEM;
- atomic_set(&op->n_pages, 1);
- trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_alloc_one);
-
- spin_lock(&cookie->lock);
-
- if (!fscache_cookie_enabled(cookie) ||
- hlist_empty(&cookie->backing_objects))
- goto nobufs_unlock;
- object = hlist_entry(cookie->backing_objects.first,
- struct fscache_object, cookie_link);
-
- __fscache_use_cookie(cookie);
- if (fscache_submit_op(object, &op->op) < 0)
- goto nobufs_unlock_dec;
- spin_unlock(&cookie->lock);
-
- fscache_stat(&fscache_n_alloc_ops);
-
- ret = fscache_wait_for_operation_activation(
- object, &op->op,
- __fscache_stat(&fscache_n_alloc_op_waits),
- __fscache_stat(&fscache_n_allocs_object_dead));
- if (ret < 0)
- goto error;
-
- /* ask the cache to honour the operation */
- fscache_stat(&fscache_n_cop_allocate_page);
- ret = object->cache->ops->allocate_page(op, page, gfp);
- fscache_stat_d(&fscache_n_cop_allocate_page);
-
-error:
- if (ret == -ERESTARTSYS)
- fscache_stat(&fscache_n_allocs_intr);
- else 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_dec:
- wake_cookie = __fscache_unuse_cookie(cookie);
-nobufs_unlock:
- spin_unlock(&cookie->lock);
- fscache_put_retrieval(op);
- if (wake_cookie)
- __fscache_wake_unused_cookie(cookie);
-nobufs:
- fscache_stat(&fscache_n_allocs_nobufs);
- _leave(" = -ENOBUFS");
- return -ENOBUFS;
-}
-EXPORT_SYMBOL(__fscache_alloc_page);
-
-/*
- * Unmark pages allocate in the readahead code path (via:
- * fscache_readpages_or_alloc) after delegating to the base filesystem
- */
-void __fscache_readpages_cancel(struct fscache_cookie *cookie,
- struct list_head *pages)
-{
- struct page *page;
-
- list_for_each_entry(page, pages, lru) {
- if (PageFsCache(page))
- __fscache_uncache_page(cookie, page);
- }
-}
-EXPORT_SYMBOL(__fscache_readpages_cancel);
-
-/*
- * 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;
- struct page *page;
- unsigned n;
- void *results[1];
- int ret;
-
- _enter("{OP%x,%d}", op->op.debug_id, atomic_read(&op->op.usage));
-
-again:
- spin_lock(&object->lock);
- cookie = object->cookie;
-
- if (!fscache_object_is_active(object)) {
- /* If we get here, then the on-disk cache object likely no
- * longer exists, so we should just cancel this write
- * operation.
- */
- spin_unlock(&object->lock);
- fscache_op_complete(&op->op, true);
- _leave(" [inactive]");
- return;
- }
-
- if (!cookie) {
- /* If we get here, then the cookie belonging to the object was
- * detached, probably by the cookie being withdrawn due to
- * memory pressure, which means that the pages we might write
- * to the cache from no longer exist - therefore, we can just
- * cancel this write operation.
- */
- spin_unlock(&object->lock);
- fscache_op_complete(&op->op, true);
- _leave(" [cancel] op{f=%lx s=%u} obj{s=%s f=%lx}",
- _op->flags, _op->state, object->state->short_name,
- object->flags);
- return;
- }
-
- spin_lock(&cookie->stores_lock);
-
- fscache_stat(&fscache_n_store_calls);
-
- /* find a page to store */
- results[0] = NULL;
- page = NULL;
- n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, 1,
- FSCACHE_COOKIE_PENDING_TAG);
- trace_fscache_gang_lookup(cookie, &op->op, results, n, op->store_limit);
- if (n != 1)
- goto superseded;
- page = results[0];
- _debug("gang %d [%lx]", n, page->index);
-
- radix_tree_tag_set(&cookie->stores, page->index,
- FSCACHE_COOKIE_STORING_TAG);
- radix_tree_tag_clear(&cookie->stores, page->index,
- FSCACHE_COOKIE_PENDING_TAG);
- trace_fscache_page(cookie, page, fscache_page_radix_pend2store);
-
- spin_unlock(&cookie->stores_lock);
- spin_unlock(&object->lock);
-
- if (page->index >= op->store_limit)
- goto discard_page;
-
- fscache_stat(&fscache_n_store_pages);
- fscache_stat(&fscache_n_cop_write_page);
- ret = object->cache->ops->write_page(op, page);
- fscache_stat_d(&fscache_n_cop_write_page);
- trace_fscache_wrote_page(cookie, page, &op->op, ret);
- fscache_end_page_write(object, page);
- if (ret < 0) {
- fscache_abort_object(object);
- fscache_op_complete(&op->op, true);
- } else {
- fscache_enqueue_operation(&op->op);
- }
-
- _leave("");
- return;
-
-discard_page:
- fscache_stat(&fscache_n_store_pages_over_limit);
- trace_fscache_wrote_page(cookie, page, &op->op, -ENOBUFS);
- fscache_end_page_write(object, page);
- goto again;
-
-superseded:
- /* this writer is going away and there aren't any more things to
- * write */
- _debug("cease");
- spin_unlock(&cookie->stores_lock);
- clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
- spin_unlock(&object->lock);
- fscache_op_complete(&op->op, false);
- _leave("");
-}
-
-/*
- * Clear the pages pending writing for invalidation
- */
-void fscache_invalidate_writes(struct fscache_cookie *cookie)
-{
- struct page *page;
- void *results[16];
- int n, i;
-
- _enter("");
-
- for (;;) {
- spin_lock(&cookie->stores_lock);
- n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0,
- ARRAY_SIZE(results),
- FSCACHE_COOKIE_PENDING_TAG);
- if (n == 0) {
- spin_unlock(&cookie->stores_lock);
- break;
- }
-
- for (i = n - 1; i >= 0; i--) {
- page = results[i];
- radix_tree_delete(&cookie->stores, page->index);
- trace_fscache_page(cookie, page, fscache_page_radix_delete);
- trace_fscache_page(cookie, page, fscache_page_inval);
- }
-
- spin_unlock(&cookie->stores_lock);
-
- for (i = n - 1; i >= 0; i--)
- put_page(results[i]);
- }
-
- wake_up_bit(&cookie->flags, 0);
- trace_fscache_wake_cookie(cookie);
-
- _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
- *
- * (b) writes deferred till post-creation (mark page for writing and
- * return immediately)
- *
- * (2) negative lookup, object created, initial fill being made from netfs
- *
- * (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,
- loff_t object_size,
- gfp_t gfp)
-{
- struct fscache_storage *op;
- struct fscache_object *object;
- bool wake_cookie = false;
- 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);
-
- if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) {
- _leave(" = -ENOBUFS [invalidating]");
- return -ENOBUFS;
- }
-
- op = kzalloc(sizeof(*op), GFP_NOIO | __GFP_NOMEMALLOC | __GFP_NORETRY);
- if (!op)
- goto nomem;
-
- fscache_operation_init(cookie, &op->op, fscache_write_op, NULL,
- fscache_release_write_op);
- op->op.flags = FSCACHE_OP_ASYNC |
- (1 << FSCACHE_OP_WAITING) |
- (1 << FSCACHE_OP_UNUSE_COOKIE);
-
- ret = radix_tree_maybe_preload(gfp & ~__GFP_HIGHMEM);
- if (ret < 0)
- goto nomem_free;
-
- trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_write_one);
-
- ret = -ENOBUFS;
- spin_lock(&cookie->lock);
-
- if (!fscache_cookie_enabled(cookie) ||
- 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;
-
- trace_fscache_page(cookie, page, fscache_page_write);
-
- /* add the page to the pending-storage radix tree on the backing
- * object */
- spin_lock(&object->lock);
-
- if (object->store_limit_l != object_size)
- fscache_set_store_limit(object, object_size);
-
- spin_lock(&cookie->stores_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;
- }
-
- trace_fscache_page(cookie, page, fscache_page_radix_insert);
- radix_tree_tag_set(&cookie->stores, page->index,
- FSCACHE_COOKIE_PENDING_TAG);
- trace_fscache_page(cookie, page, fscache_page_radix_set_pend);
- get_page(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(&cookie->stores_lock);
- spin_unlock(&object->lock);
-
- op->op.debug_id = atomic_inc_return(&fscache_op_debug_id);
- op->store_limit = object->store_limit;
-
- __fscache_use_cookie(cookie);
- 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 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(&cookie->stores_lock);
- spin_unlock(&object->lock);
- spin_unlock(&cookie->lock);
- radix_tree_preload_end();
- fscache_put_operation(&op->op);
- fscache_stat(&fscache_n_stores_ok);
- _leave(" = 0");
- return 0;
-
-submit_failed:
- spin_lock(&cookie->stores_lock);
- radix_tree_delete(&cookie->stores, page->index);
- trace_fscache_page(cookie, page, fscache_page_radix_delete);
- spin_unlock(&cookie->stores_lock);
- wake_cookie = __fscache_unuse_cookie(cookie);
- put_page(page);
- ret = -ENOBUFS;
- goto nobufs;
-
-nobufs_unlock_obj:
- spin_unlock(&cookie->stores_lock);
- spin_unlock(&object->lock);
-nobufs:
- spin_unlock(&cookie->lock);
- radix_tree_preload_end();
- fscache_put_operation(&op->op);
- if (wake_cookie)
- __fscache_wake_unused_cookie(cookie);
- fscache_stat(&fscache_n_stores_nobufs);
- _leave(" = -ENOBUFS");
- return -ENOBUFS;
-
-nomem_free:
- fscache_put_operation(&op->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;
-
- trace_fscache_page(cookie, page, fscache_page_uncache);
-
- /* 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 */
- fscache_stat(&fscache_n_cop_uncache_page);
- object->cache->ops->uncache_page(object, page);
- fscache_stat_d(&fscache_n_cop_uncache_page);
- goto done;
- }
-
-done_unlock:
- spin_unlock(&cookie->lock);
-done:
- _leave("");
-}
-EXPORT_SYMBOL(__fscache_uncache_page);
-
-/**
- * fscache_mark_page_cached - Mark a page as being cached
- * @op: The retrieval op pages are being marked for
- * @page: The page to be marked
- *
- * Mark a netfs page as being cached. After this is called, the netfs
- * must call fscache_uncache_page() to remove the mark.
- */
-void fscache_mark_page_cached(struct fscache_retrieval *op, struct page *page)
-{
- struct fscache_cookie *cookie = op->op.object->cookie;
-
-#ifdef CONFIG_FSCACHE_STATS
- atomic_inc(&fscache_n_marks);
-#endif
-
- trace_fscache_page(cookie, page, fscache_page_cached);
-
- _debug("- mark %p{%lx}", page, page->index);
- if (TestSetPageFsCache(page)) {
- static bool once_only;
- if (!once_only) {
- once_only = true;
- pr_warn("Cookie type %s marked page %lx multiple times\n",
- cookie->def->name, page->index);
- }
- }
-
- if (cookie->def->mark_page_cached)
- cookie->def->mark_page_cached(cookie->netfs_data,
- op->mapping, page);
-}
-EXPORT_SYMBOL(fscache_mark_page_cached);
-
-/**
- * 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)
-{
- unsigned long loop;
-
- for (loop = 0; loop < pagevec->nr; loop++)
- fscache_mark_page_cached(op, pagevec->pages[loop]);
-
- pagevec_reinit(pagevec);
-}
-EXPORT_SYMBOL(fscache_mark_pages_cached);
-
-/*
- * Uncache all the pages in an inode that are marked PG_fscache, assuming them
- * to be associated with the given cookie.
- */
-void __fscache_uncache_all_inode_pages(struct fscache_cookie *cookie,
- struct inode *inode)
-{
- struct address_space *mapping = inode->i_mapping;
- struct pagevec pvec;
- pgoff_t next;
- int i;
-
- _enter("%p,%p", cookie, inode);
-
- if (!mapping || mapping->nrpages == 0) {
- _leave(" [no pages]");
- return;
- }
-
- pagevec_init(&pvec);
- next = 0;
- do {
- if (!pagevec_lookup(&pvec, mapping, &next))
- break;
- for (i = 0; i < pagevec_count(&pvec); i++) {
- struct page *page = pvec.pages[i];
- if (PageFsCache(page)) {
- __fscache_wait_on_page_write(cookie, page);
- __fscache_uncache_page(cookie, page);
- }
- }
- pagevec_release(&pvec);
- cond_resched();
- } while (next);
-
- _leave("");
-}
-EXPORT_SYMBOL(__fscache_uncache_all_inode_pages);