Merge commit 'origin/master' into for-linus/xen/master

* commit 'origin/master': (4825 commits)
  Fix build errors due to CONFIG_BRANCH_TRACER=y
  parport: Use the PCI IRQ if offered
  tty: jsm cleanups
  Adjust path to gpio headers
  KGDB_SERIAL_CONSOLE check for module
  Change KCONFIG name
  tty: Blackin CTS/RTS
  Change hardware flow control from poll to interrupt driven
  Add support for the MAX3100 SPI UART.
  lanana: assign a device name and numbering for MAX3100
  serqt: initial clean up pass for tty side
  tty: Use the generic RS485 ioctl on CRIS
  tty: Correct inline types for tty_driver_kref_get()
  splice: fix deadlock in splicing to file
  nilfs2: support nanosecond timestamp
  nilfs2: introduce secondary super block
  nilfs2: simplify handling of active state of segments
  nilfs2: mark minor flag for checkpoint created by internal operation
  nilfs2: clean up sketch file
  nilfs2: super block operations fix endian bug
  ...

Conflicts:
	arch/x86/include/asm/thread_info.h
	arch/x86/lguest/boot.c
	drivers/xen/manage.c

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);