Initial import

1 files changed, 1932 insertions, 0 deletions

diff --git a/kernel/power/tuxonice_io.c b/kernel/power/tuxonice_io.c
new file mode 100644
index 000000000..91b0c4fd0
--- /dev/null
+++ b/kernel/power/tuxonice_io.c
@@ -0,0 +1,1932 @@
+/*
+ * kernel/power/tuxonice_io.c
+ *
+ * Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu>
+ * Copyright (C) 1998,2001,2002 Pavel Machek <pavel@suse.cz>
+ * Copyright (C) 2002-2003 Florent Chabaud <fchabaud@free.fr>
+ * Copyright (C) 2002-2015 Nigel Cunningham (nigel at nigelcunningham com au)
+ *
+ * This file is released under the GPLv2.
+ *
+ * It contains high level IO routines for hibernating.
+ *
+ */
+
+#include <linux/suspend.h>
+#include <linux/version.h>
+#include <linux/utsname.h>
+#include <linux/mount.h>
+#include <linux/highmem.h>
+#include <linux/kthread.h>
+#include <linux/cpu.h>
+#include <linux/fs_struct.h>
+#include <linux/bio.h>
+#include <linux/fs_uuid.h>
+#include <linux/kmod.h>
+#include <asm/tlbflush.h>
+
+#include "tuxonice.h"
+#include "tuxonice_modules.h"
+#include "tuxonice_pageflags.h"
+#include "tuxonice_io.h"
+#include "tuxonice_ui.h"
+#include "tuxonice_storage.h"
+#include "tuxonice_prepare_image.h"
+#include "tuxonice_extent.h"
+#include "tuxonice_sysfs.h"
+#include "tuxonice_builtin.h"
+#include "tuxonice_checksum.h"
+#include "tuxonice_alloc.h"
+char alt_resume_param[256];
+
+/* Version read from image header at resume */
+static int toi_image_header_version;
+
+#define read_if_version(VERS, VAR, DESC, ERR_ACT) do {					\
+	if (likely(toi_image_header_version >= VERS))				\
+		if (toiActiveAllocator->rw_header_chunk(READ, NULL,		\
+					(char *) &VAR, sizeof(VAR))) {		\
+			abort_hibernate(TOI_FAILED_IO, "Failed to read DESC.");	\
+			ERR_ACT;					\
+		}								\
+} while(0)									\
+
+/* Variables shared between threads and updated under the mutex */
+static int io_write, io_finish_at, io_base, io_barmax, io_pageset, io_result;
+static int io_index, io_nextupdate, io_pc, io_pc_step;
+static DEFINE_MUTEX(io_mutex);
+static DEFINE_PER_CPU(struct page *, last_sought);
+static DEFINE_PER_CPU(struct page *, last_high_page);
+static DEFINE_PER_CPU(char *, checksum_locn);
+static DEFINE_PER_CPU(struct pbe *, last_low_page);
+static atomic_t io_count;
+atomic_t toi_io_workers;
+
+static int using_flusher;
+
+DECLARE_WAIT_QUEUE_HEAD(toi_io_queue_flusher);
+
+int toi_bio_queue_flusher_should_finish;
+
+int toi_max_workers;
+
+static char *image_version_error = "The image header version is newer than " \
+	"this kernel supports.";
+
+struct toi_module_ops *first_filter;
+
+static atomic_t toi_num_other_threads;
+static DECLARE_WAIT_QUEUE_HEAD(toi_worker_wait_queue);
+enum toi_worker_commands {
+	TOI_IO_WORKER_STOP,
+	TOI_IO_WORKER_RUN,
+	TOI_IO_WORKER_EXIT
+};
+static enum toi_worker_commands toi_worker_command;
+
+/**
+ * toi_attempt_to_parse_resume_device - determine if we can hibernate
+ *
+ * Can we hibernate, using the current resume= parameter?
+ **/
+int toi_attempt_to_parse_resume_device(int quiet)
+{
+	struct list_head *Allocator;
+	struct toi_module_ops *thisAllocator;
+	int result, returning = 0;
+
+	if (toi_activate_storage(0))
+		return 0;
+
+	toiActiveAllocator = NULL;
+	clear_toi_state(TOI_RESUME_DEVICE_OK);
+	clear_toi_state(TOI_CAN_RESUME);
+	clear_result_state(TOI_ABORTED);
+
+	if (!toiNumAllocators) {
+		if (!quiet)
+			printk(KERN_INFO "TuxOnIce: No storage allocators have "
+				"been registered. Hibernating will be "
+				"disabled.\n");
+		goto cleanup;
+	}
+
+	list_for_each(Allocator, &toiAllocators) {
+		thisAllocator = list_entry(Allocator, struct toi_module_ops,
+								type_list);
+
+		/*
+		 * Not sure why you'd want to disable an allocator, but
+		 * we should honour the flag if we're providing it
+		 */
+		if (!thisAllocator->enabled)
+			continue;
+
+		result = thisAllocator->parse_sig_location(
+				resume_file, (toiNumAllocators == 1),
+				quiet);
+
+		switch (result) {
+		case -EINVAL:
+			/* For this allocator, but not a valid
+			 * configuration. Error already printed. */
+			goto cleanup;
+
+		case 0:
+			/* For this allocator and valid. */
+			toiActiveAllocator = thisAllocator;
+
+			set_toi_state(TOI_RESUME_DEVICE_OK);
+			set_toi_state(TOI_CAN_RESUME);
+			returning = 1;
+			goto cleanup;
+		}
+	}
+	if (!quiet)
+		printk(KERN_INFO "TuxOnIce: No matching enabled allocator "
+				"found. Resuming disabled.\n");
+cleanup:
+	toi_deactivate_storage(0);
+	return returning;
+}
+
+void attempt_to_parse_resume_device2(void)
+{
+	toi_prepare_usm();
+	toi_attempt_to_parse_resume_device(0);
+	toi_cleanup_usm();
+}
+
+void save_restore_alt_param(int replace, int quiet)
+{
+	static char resume_param_save[255];
+	static unsigned long toi_state_save;
+
+	if (replace) {
+		toi_state_save = toi_state;
+		strcpy(resume_param_save, resume_file);
+		strcpy(resume_file, alt_resume_param);
+	} else {
+		strcpy(resume_file, resume_param_save);
+		toi_state = toi_state_save;
+	}
+	toi_attempt_to_parse_resume_device(quiet);
+}
+
+void attempt_to_parse_alt_resume_param(void)
+{
+	int ok = 0;
+
+	/* Temporarily set resume_param to the poweroff value */
+	if (!strlen(alt_resume_param))
+		return;
+
+	printk(KERN_INFO "=== Trying Poweroff Resume2 ===\n");
+	save_restore_alt_param(SAVE, NOQUIET);
+	if (test_toi_state(TOI_CAN_RESUME))
+		ok = 1;
+
+	printk(KERN_INFO "=== Done ===\n");
+	save_restore_alt_param(RESTORE, QUIET);
+
+	/* If not ok, clear the string */
+	if (ok)
+		return;
+
+	printk(KERN_INFO "Can't resume from that location; clearing "
+			"alt_resume_param.\n");
+	alt_resume_param[0] = '\0';
+}
+
+/**
+ * noresume_reset_modules - reset data structures in case of non resuming
+ *
+ * When we read the start of an image, modules (and especially the
+ * active allocator) might need to reset data structures if we
+ * decide to remove the image rather than resuming from it.
+ **/
+static void noresume_reset_modules(void)
+{
+	struct toi_module_ops *this_filter;
+
+	list_for_each_entry(this_filter, &toi_filters, type_list)
+		if (this_filter->noresume_reset)
+			this_filter->noresume_reset();
+
+	if (toiActiveAllocator && toiActiveAllocator->noresume_reset)
+		toiActiveAllocator->noresume_reset();
+}
+
+/**
+ * fill_toi_header - fill the hibernate header structure
+ * @struct toi_header: Header data structure to be filled.
+ **/
+static int fill_toi_header(struct toi_header *sh)
+{
+	int i, error;
+
+	error = init_header((struct swsusp_info *) sh);
+	if (error)
+		return error;
+
+	sh->pagedir = pagedir1;
+	sh->pageset_2_size = pagedir2.size;
+	sh->param0 = toi_result;
+	sh->param1 = toi_bkd.toi_action;
+	sh->param2 = toi_bkd.toi_debug_state;
+	sh->param3 = toi_bkd.toi_default_console_level;
+	sh->root_fs = current->fs->root.mnt->mnt_sb->s_dev;
+	for (i = 0; i < 4; i++)
+		sh->io_time[i/2][i%2] = toi_bkd.toi_io_time[i/2][i%2];
+	sh->bkd = boot_kernel_data_buffer;
+	return 0;
+}
+
+/**
+ * rw_init_modules - initialize modules
+ * @rw:		Whether we are reading of writing an image.
+ * @which:	Section of the image being processed.
+ *
+ * Iterate over modules, preparing the ones that will be used to read or write
+ * data.
+ **/
+static int rw_init_modules(int rw, int which)
+{
+	struct toi_module_ops *this_module;
+	/* Initialise page transformers */
+	list_for_each_entry(this_module, &toi_filters, type_list) {
+		if (!this_module->enabled)
+			continue;
+		if (this_module->rw_init && this_module->rw_init(rw, which)) {
+			abort_hibernate(TOI_FAILED_MODULE_INIT,
+				"Failed to initialize the %s filter.",
+				this_module->name);
+			return 1;
+		}
+	}
+
+	/* Initialise allocator */
+	if (toiActiveAllocator->rw_init(rw, which)) {
+		abort_hibernate(TOI_FAILED_MODULE_INIT,
+				"Failed to initialise the allocator.");
+		return 1;
+	}
+
+	/* Initialise other modules */
+	list_for_each_entry(this_module, &toi_modules, module_list) {
+		if (!this_module->enabled ||
+		    this_module->type == FILTER_MODULE ||
+		    this_module->type == WRITER_MODULE)
+			continue;
+		if (this_module->rw_init && this_module->rw_init(rw, which)) {
+			set_abort_result(TOI_FAILED_MODULE_INIT);
+			printk(KERN_INFO "Setting aborted flag due to module "
+					"init failure.\n");
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * rw_cleanup_modules - cleanup modules
+ * @rw:	Whether we are reading of writing an image.
+ *
+ * Cleanup components after reading or writing a set of pages.
+ * Only the allocator may fail.
+ **/
+static int rw_cleanup_modules(int rw)
+{
+	struct toi_module_ops *this_module;
+	int result = 0;
+
+	/* Cleanup other modules */
+	list_for_each_entry(this_module, &toi_modules, module_list) {
+		if (!this_module->enabled ||
+		    this_module->type == FILTER_MODULE ||
+		    this_module->type == WRITER_MODULE)
+			continue;
+		if (this_module->rw_cleanup)
+			result |= this_module->rw_cleanup(rw);
+	}
+
+	/* Flush data and cleanup */
+	list_for_each_entry(this_module, &toi_filters, type_list) {
+		if (!this_module->enabled)
+			continue;
+		if (this_module->rw_cleanup)
+			result |= this_module->rw_cleanup(rw);
+	}
+
+	result |= toiActiveAllocator->rw_cleanup(rw);
+
+	return result;
+}
+
+static struct page *copy_page_from_orig_page(struct page *orig_page, int is_high)
+{
+	int index, min, max;
+	struct page *high_page = NULL,
+		    **my_last_high_page = raw_cpu_ptr(&last_high_page),
+		    **my_last_sought = raw_cpu_ptr(&last_sought);
+	struct pbe *this, **my_last_low_page = raw_cpu_ptr(&last_low_page);
+	void *compare;
+
+	if (is_high) {
+		if (*my_last_sought && *my_last_high_page &&
+				*my_last_sought < orig_page)
+			high_page = *my_last_high_page;
+		else
+			high_page = (struct page *) restore_highmem_pblist;
+		this = (struct pbe *) kmap(high_page);
+		compare = orig_page;
+	} else {
+		if (*my_last_sought && *my_last_low_page &&
+				*my_last_sought < orig_page)
+			this = *my_last_low_page;
+		else
+			this = restore_pblist;
+		compare = page_address(orig_page);
+	}
+
+	*my_last_sought = orig_page;
+
+	/* Locate page containing pbe */
+	while (this[PBES_PER_PAGE - 1].next &&
+			this[PBES_PER_PAGE - 1].orig_address < compare) {
+		if (is_high) {
+			struct page *next_high_page = (struct page *)
+				this[PBES_PER_PAGE - 1].next;
+			kunmap(high_page);
+			this = kmap(next_high_page);
+			high_page = next_high_page;
+		} else
+			this = this[PBES_PER_PAGE - 1].next;
+	}
+
+	/* Do a binary search within the page */
+	min = 0;
+	max = PBES_PER_PAGE;
+	index = PBES_PER_PAGE / 2;
+	while (max - min) {
+		if (!this[index].orig_address ||
+		    this[index].orig_address > compare)
+			max = index;
+		else if (this[index].orig_address == compare) {
+			if (is_high) {
+				struct page *page = this[index].address;
+				*my_last_high_page = high_page;
+				kunmap(high_page);
+				return page;
+			}
+			*my_last_low_page = this;
+			return virt_to_page(this[index].address);
+		} else
+			min = index;
+		index = ((max + min) / 2);
+	};
+
+	if (is_high)
+		kunmap(high_page);
+
+	abort_hibernate(TOI_FAILED_IO, "Failed to get destination page for"
+		" orig page %p. This[min].orig_address=%p.\n", orig_page,
+		this[index].orig_address);
+	return NULL;
+}
+
+/**
+ * write_next_page - write the next page in a pageset
+ * @data_pfn: The pfn where the next data to write is located.
+ * @my_io_index: The index of the page in the pageset.
+ * @write_pfn: The pfn number to write in the image (where the data belongs).
+ *
+ * Get the pfn of the next page to write, map the page if necessary and do the
+ * write.
+ **/
+static int write_next_page(unsigned long *data_pfn, int *my_io_index,
+		unsigned long *write_pfn)
+{
+	struct page *page;
+	char **my_checksum_locn = raw_cpu_ptr(&checksum_locn);
+	int result = 0, was_present;
+
+	*data_pfn = memory_bm_next_pfn(io_map, 0);
+
+	/* Another thread could have beaten us to it. */
+	if (*data_pfn == BM_END_OF_MAP) {
+		if (atomic_read(&io_count)) {
+			printk(KERN_INFO "Ran out of pfns but io_count is "
+					"still %d.\n", atomic_read(&io_count));
+			BUG();
+		}
+		mutex_unlock(&io_mutex);
+		return -ENODATA;
+	}
+
+	*my_io_index = io_finish_at - atomic_sub_return(1, &io_count);
+
+	memory_bm_clear_bit(io_map, 0, *data_pfn);
+	page = pfn_to_page(*data_pfn);
+
+	was_present = kernel_page_present(page);
+	if (!was_present)
+		kernel_map_pages(page, 1, 1);
+
+	if (io_pageset == 1)
+		*write_pfn = memory_bm_next_pfn(pageset1_map, 0);
+	else {
+		*write_pfn = *data_pfn;
+		*my_checksum_locn = tuxonice_get_next_checksum();
+	}
+
+	TOI_TRACE_DEBUG(*data_pfn, "_PS%d_write %d", io_pageset, *my_io_index);
+
+	mutex_unlock(&io_mutex);
+
+	if (io_pageset == 2 && tuxonice_calc_checksum(page, *my_checksum_locn))
+		return 1;
+
+	result = first_filter->write_page(*write_pfn, TOI_PAGE, page,
+			PAGE_SIZE);
+
+	if (!was_present)
+		kernel_map_pages(page, 1, 0);
+
+	return result;
+}
+
+/**
+ * read_next_page - read the next page in a pageset
+ * @my_io_index: The index of the page in the pageset.
+ * @write_pfn: The pfn in which the data belongs.
+ *
+ * Read a page of the image into our buffer. It can happen (here and in the
+ * write routine) that threads don't get run until after other CPUs have done
+ * all the work. This was the cause of the long standing issue with
+ * occasionally getting -ENODATA errors at the end of reading the image. We
+ * therefore need to check there's actually a page to read before trying to
+ * retrieve one.
+ **/
+
+static int read_next_page(int *my_io_index, unsigned long *write_pfn,
+		struct page *buffer)
+{
+	unsigned int buf_size = PAGE_SIZE;
+	unsigned long left = atomic_read(&io_count);
+
+	if (!left)
+		return -ENODATA;
+
+	/* Start off assuming the page we read isn't resaved */
+	*my_io_index = io_finish_at - atomic_sub_return(1, &io_count);
+
+	mutex_unlock(&io_mutex);
+
+	/*
+	 * Are we aborting? If so, don't submit any more I/O as
+	 * resetting the resume_attempted flag (from ui.c) will
+	 * clear the bdev flags, making this thread oops.
+	 */
+	if (unlikely(test_toi_state(TOI_STOP_RESUME))) {
+		atomic_dec(&toi_io_workers);
+		if (!atomic_read(&toi_io_workers)) {
+			/*
+			 * So we can be sure we'll have memory for
+			 * marking that we haven't resumed.
+			 */
+			rw_cleanup_modules(READ);
+			set_toi_state(TOI_IO_STOPPED);
+		}
+		while (1)
+			schedule();
+	}
+
+	/*
+	 * See toi_bio_read_page in tuxonice_bio.c:
+	 * read the next page in the image.
+	 */
+	return first_filter->read_page(write_pfn, TOI_PAGE, buffer, &buf_size);
+}
+
+static void use_read_page(unsigned long write_pfn, struct page *buffer)
+{
+	struct page *final_page = pfn_to_page(write_pfn),
+		    *copy_page = final_page;
+	char *virt, *buffer_virt;
+	int was_present, cpu = smp_processor_id();
+	unsigned long idx = 0;
+
+	if (io_pageset == 1 && (!pageset1_copy_map ||
+			!memory_bm_test_bit(pageset1_copy_map, cpu, write_pfn))) {
+		int is_high = PageHighMem(final_page);
+		copy_page = copy_page_from_orig_page(is_high ? (void *) write_pfn : final_page, is_high);
+	}
+
+	if (!memory_bm_test_bit(io_map, cpu, write_pfn)) {
+	        int test = !memory_bm_test_bit(io_map, cpu, write_pfn);
+		toi_message(TOI_IO, TOI_VERBOSE, 0, "Discard %ld (%d).", write_pfn, test);
+		mutex_lock(&io_mutex);
+		idx = atomic_add_return(1, &io_count);
+		mutex_unlock(&io_mutex);
+		return;
+	}
+
+	virt = kmap(copy_page);
+	buffer_virt = kmap(buffer);
+	was_present = kernel_page_present(copy_page);
+	if (!was_present)
+		kernel_map_pages(copy_page, 1, 1);
+	memcpy(virt, buffer_virt, PAGE_SIZE);
+	if (!was_present)
+		kernel_map_pages(copy_page, 1, 0);
+	kunmap(copy_page);
+	kunmap(buffer);
+	memory_bm_clear_bit(io_map, cpu, write_pfn);
+	TOI_TRACE_DEBUG(write_pfn, "_PS%d_read", io_pageset);
+}
+
+static unsigned long status_update(int writing, unsigned long done,
+		unsigned long ticks)
+{
+	int cs_index = writing ? 0 : 1;
+	unsigned long ticks_so_far = toi_bkd.toi_io_time[cs_index][1] + ticks;
+	unsigned long msec = jiffies_to_msecs(abs(ticks_so_far));
+	unsigned long pgs_per_s, estimate = 0, pages_left;
+
+	if (msec) {
+		pages_left = io_barmax - done;
+		pgs_per_s = 1000 * done / msec;
+		if (pgs_per_s)
+			estimate = DIV_ROUND_UP(pages_left, pgs_per_s);
+	}
+
+	if (estimate && ticks > HZ / 2)
+		return toi_update_status(done, io_barmax,
+			" %d/%d MB (%lu sec left)",
+			MB(done+1), MB(io_barmax), estimate);
+
+	return toi_update_status(done, io_barmax, " %d/%d MB",
+		MB(done+1), MB(io_barmax));
+}
+
+/**
+ * worker_rw_loop - main loop to read/write pages
+ *
+ * The main I/O loop for reading or writing pages. The io_map bitmap is used to
+ * track the pages to read/write.
+ * If we are reading, the pages are loaded to their final (mapped) pfn.
+ * Data is non zero iff this is a thread started via start_other_threads.
+ * In that case, we stay in here until told to quit.
+ **/
+static int worker_rw_loop(void *data)
+{
+	unsigned long data_pfn, write_pfn, next_jiffies = jiffies + HZ / 4,
+		      jif_index = 1, start_time = jiffies, thread_num;
+	int result = 0, my_io_index = 0, last_worker;
+	struct page *buffer = toi_alloc_page(28, TOI_ATOMIC_GFP);
+	cpumask_var_t orig_mask;
+
+        if (!alloc_cpumask_var(&orig_mask, GFP_KERNEL)) {
+		printk(KERN_EMERG "Failed to allocate cpumask for TuxOnIce I/O thread %ld.\n", (unsigned long) data);
+                result = -ENOMEM;
+                goto out;
+        }
+
+	cpumask_copy(orig_mask, tsk_cpus_allowed(current));
+
+	current->flags |= PF_NOFREEZE;
+
+top:
+	mutex_lock(&io_mutex);
+	thread_num = atomic_read(&toi_io_workers);
+
+	cpumask_copy(tsk_cpus_allowed(current), orig_mask);
+	schedule();
+
+	atomic_inc(&toi_io_workers);
+
+	while (atomic_read(&io_count) >= atomic_read(&toi_io_workers) &&
+		!(io_write && test_result_state(TOI_ABORTED)) &&
+		toi_worker_command == TOI_IO_WORKER_RUN) {
+		if (!thread_num && jiffies > next_jiffies) {
+			next_jiffies += HZ / 4;
+			if (toiActiveAllocator->update_throughput_throttle)
+				toiActiveAllocator->update_throughput_throttle(
+						jif_index);
+			jif_index++;
+		}
+
+		/*
+		 * What page to use? If reading, don't know yet which page's
+		 * data will be read, so always use the buffer. If writing,
+		 * use the copy (Pageset1) or original page (Pageset2), but
+		 * always write the pfn of the original page.
+		 */
+		if (io_write)
+			result = write_next_page(&data_pfn, &my_io_index,
+					&write_pfn);
+		else /* Reading */
+			result = read_next_page(&my_io_index, &write_pfn,
+					buffer);
+
+		if (result) {
+			mutex_lock(&io_mutex);
+			/* Nothing to do? */
+			if (result == -ENODATA) {
+				toi_message(TOI_IO, TOI_VERBOSE, 0,
+					"Thread %d has no more work.",
+					smp_processor_id());
+				break;
+			}
+
+			io_result = result;
+
+			if (io_write) {
+				printk(KERN_INFO "Write chunk returned %d.\n",
+						result);
+				abort_hibernate(TOI_FAILED_IO,
+					"Failed to write a chunk of the "
+					"image.");
+				break;
+			}
+
+			if (io_pageset == 1) {
+				printk(KERN_ERR "\nBreaking out of I/O loop "
+					"because of result code %d.\n", result);
+				break;
+			}
+			panic("Read chunk returned (%d)", result);
+		}
+
+		/*
+		 * Discard reads of resaved pages while reading ps2
+		 * and unwanted pages while rereading ps2 when aborting.
+		 */
+		if (!io_write) {
+			if (!PageResave(pfn_to_page(write_pfn)))
+				use_read_page(write_pfn, buffer);
+			else {
+				mutex_lock(&io_mutex);
+				toi_message(TOI_IO, TOI_VERBOSE, 0,
+						"Resaved %ld.", write_pfn);
+				atomic_inc(&io_count);
+				mutex_unlock(&io_mutex);
+			}
+		}
+
+		if (!thread_num) {
+			if(my_io_index + io_base > io_nextupdate)
+				io_nextupdate = status_update(io_write,
+						my_io_index + io_base,
+						jiffies - start_time);
+
+			if (my_io_index > io_pc) {
+				printk(KERN_CONT "...%d%%", 20 * io_pc_step);
+				io_pc_step++;
+				io_pc = io_finish_at * io_pc_step / 5;
+			}
+		}
+
+		toi_cond_pause(0, NULL);
+
+		/*
+		 * Subtle: If there's less I/O still to be done than threads
+		 * running, quit. This stops us doing I/O beyond the end of
+		 * the image when reading.
+		 *
+		 * Possible race condition. Two threads could do the test at
+		 * the same time; one should exit and one should continue.
+		 * Therefore we take the mutex before comparing and exiting.
+		 */
+
+		mutex_lock(&io_mutex);
+	}
+
+	last_worker = atomic_dec_and_test(&toi_io_workers);
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "%d workers left.", atomic_read(&toi_io_workers));
+	mutex_unlock(&io_mutex);
+
+	if ((unsigned long) data && toi_worker_command != TOI_IO_WORKER_EXIT) {
+		/* Were we the last thread and we're using a flusher thread? */
+		if (last_worker && using_flusher) {
+			toiActiveAllocator->finish_all_io();
+		}
+		/* First, if we're doing I/O, wait for it to finish */
+		wait_event(toi_worker_wait_queue, toi_worker_command != TOI_IO_WORKER_RUN);
+		/* Then wait to be told what to do next */
+		wait_event(toi_worker_wait_queue, toi_worker_command != TOI_IO_WORKER_STOP);
+		if (toi_worker_command == TOI_IO_WORKER_RUN)
+			goto top;
+	}
+
+	if (thread_num)
+		atomic_dec(&toi_num_other_threads);
+
+out:
+	toi_message(TOI_IO, TOI_LOW, 0, "Thread %d exiting.", thread_num);
+	toi__free_page(28, buffer);
+	free_cpumask_var(orig_mask);
+
+	return result;
+}
+
+int toi_start_other_threads(void)
+{
+	int cpu;
+	struct task_struct *p;
+	int to_start = (toi_max_workers ? toi_max_workers : num_online_cpus()) - 1;
+  unsigned long num_started = 0;
+
+	if (test_action_state(TOI_NO_MULTITHREADED_IO))
+		return 0;
+
+	toi_worker_command = TOI_IO_WORKER_STOP;
+
+	for_each_online_cpu(cpu) {
+		if (num_started == to_start)
+			break;
+
+		if (cpu == smp_processor_id())
+			continue;
+
+		p = kthread_create_on_node(worker_rw_loop, (void *) num_started + 1,
+				cpu_to_node(cpu), "ktoi_io/%d", cpu);
+		if (IS_ERR(p)) {
+			printk(KERN_ERR "ktoi_io for %i failed\n", cpu);
+			continue;
+		}
+		kthread_bind(p, cpu);
+		p->flags |= PF_MEMALLOC;
+		wake_up_process(p);
+		num_started++;
+		atomic_inc(&toi_num_other_threads);
+	}
+
+	toi_message(TOI_IO, TOI_LOW, 0, "Started %d threads.", num_started);
+	return num_started;
+}
+
+void toi_stop_other_threads(void)
+{
+	toi_message(TOI_IO, TOI_LOW, 0, "Stopping other threads.");
+	toi_worker_command = TOI_IO_WORKER_EXIT;
+	wake_up(&toi_worker_wait_queue);
+}
+
+/**
+ * do_rw_loop - main highlevel function for reading or writing pages
+ *
+ * Create the io_map bitmap and call worker_rw_loop to perform I/O operations.
+ **/
+static int do_rw_loop(int write, int finish_at, struct memory_bitmap *pageflags,
+		int base, int barmax, int pageset)
+{
+	int index = 0, cpu, result = 0, workers_started;
+	unsigned long pfn, next;
+
+	first_filter = toi_get_next_filter(NULL);
+
+	if (!finish_at)
+		return 0;
+
+	io_write = write;
+	io_finish_at = finish_at;
+	io_base = base;
+	io_barmax = barmax;
+	io_pageset = pageset;
+	io_index = 0;
+	io_pc = io_finish_at / 5;
+	io_pc_step = 1;
+	io_result = 0;
+	io_nextupdate = base + 1;
+	toi_bio_queue_flusher_should_finish = 0;
+
+	for_each_online_cpu(cpu) {
+		per_cpu(last_sought, cpu) = NULL;
+		per_cpu(last_low_page, cpu) = NULL;
+		per_cpu(last_high_page, cpu) = NULL;
+	}
+
+	/* Ensure all bits clear */
+	memory_bm_clear(io_map);
+
+        memory_bm_position_reset(io_map);
+        next = memory_bm_next_pfn(io_map, 0);
+
+        BUG_ON(next != BM_END_OF_MAP);
+
+	/* Set the bits for the pages to write */
+	memory_bm_position_reset(pageflags);
+
+	pfn = memory_bm_next_pfn(pageflags, 0);
+        toi_trace_index++;
+
+	while (pfn != BM_END_OF_MAP && index < finish_at) {
+		TOI_TRACE_DEBUG(pfn, "_io_pageset_%d (%d/%d)", pageset, index + 1, finish_at);
+		memory_bm_set_bit(io_map, 0, pfn);
+		pfn = memory_bm_next_pfn(pageflags, 0);
+		index++;
+	}
+
+        BUG_ON(next != BM_END_OF_MAP || index < finish_at);
+
+        memory_bm_position_reset(io_map);
+        toi_trace_index++;
+
+	atomic_set(&io_count, finish_at);
+
+	memory_bm_position_reset(pageset1_map);
+
+	mutex_lock(&io_mutex);
+
+	clear_toi_state(TOI_IO_STOPPED);
+
+	using_flusher = (atomic_read(&toi_num_other_threads) &&
+			 toiActiveAllocator->io_flusher &&
+			 !test_action_state(TOI_NO_FLUSHER_THREAD));
+
+	workers_started = atomic_read(&toi_num_other_threads);
+
+	memory_bm_position_reset(io_map);
+	memory_bm_position_reset(pageset1_copy_map);
+
+	toi_worker_command = TOI_IO_WORKER_RUN;
+	wake_up(&toi_worker_wait_queue);
+
+	mutex_unlock(&io_mutex);
+
+	if (using_flusher)
+		result = toiActiveAllocator->io_flusher(write);
+	else
+		worker_rw_loop(NULL);
+
+	while (atomic_read(&toi_io_workers))
+		schedule();
+
+	printk(KERN_CONT "\n");
+
+	toi_worker_command = TOI_IO_WORKER_STOP;
+	wake_up(&toi_worker_wait_queue);
+
+	if (unlikely(test_toi_state(TOI_STOP_RESUME))) {
+		if (!atomic_read(&toi_io_workers)) {
+			rw_cleanup_modules(READ);
+			set_toi_state(TOI_IO_STOPPED);
+		}
+		while (1)
+			schedule();
+	}
+	set_toi_state(TOI_IO_STOPPED);
+
+	if (!io_result && !result && !test_result_state(TOI_ABORTED)) {
+		unsigned long next;
+
+		toi_update_status(io_base + io_finish_at, io_barmax,
+				" %d/%d MB ",
+				MB(io_base + io_finish_at), MB(io_barmax));
+
+		memory_bm_position_reset(io_map);
+		next = memory_bm_next_pfn(io_map, 0);
+		if  (next != BM_END_OF_MAP) {
+			printk(KERN_INFO "Finished I/O loop but still work to "
+					"do?\nFinish at = %d. io_count = %d.\n",
+					finish_at, atomic_read(&io_count));
+			printk(KERN_INFO "I/O bitmap still records work to do."
+					"%ld.\n", next);
+			BUG();
+			do {
+				cpu_relax();
+			} while (0);
+		}
+	}
+
+	return io_result ? io_result : result;
+}
+
+/**
+ * write_pageset - write a pageset to disk.
+ * @pagedir:	Which pagedir to write.
+ *
+ * Returns:
+ *	Zero on success or -1 on failure.
+ **/
+int write_pageset(struct pagedir *pagedir)
+{
+	int finish_at, base = 0;
+	int barmax = pagedir1.size + pagedir2.size;
+	long error = 0;
+	struct memory_bitmap *pageflags;
+	unsigned long start_time, end_time;
+
+	/*
+	 * Even if there is nothing to read or write, the allocator
+	 * may need the init/cleanup for it's housekeeping.  (eg:
+	 * Pageset1 may start where pageset2 ends when writing).
+	 */
+	finish_at = pagedir->size;
+
+	if (pagedir->id == 1) {
+		toi_prepare_status(DONT_CLEAR_BAR,
+				"Writing kernel & process data...");
+		base = pagedir2.size;
+		if (test_action_state(TOI_TEST_FILTER_SPEED) ||
+		    test_action_state(TOI_TEST_BIO))
+			pageflags = pageset1_map;
+		else
+			pageflags = pageset1_copy_map;
+	} else {
+		toi_prepare_status(DONT_CLEAR_BAR, "Writing caches...");
+		pageflags = pageset2_map;
+	}
+
+	start_time = jiffies;
+
+	if (rw_init_modules(WRITE, pagedir->id)) {
+		abort_hibernate(TOI_FAILED_MODULE_INIT,
+				"Failed to initialise modules for writing.");
+		error = 1;
+	}
+
+	if (!error)
+		error = do_rw_loop(WRITE, finish_at, pageflags, base, barmax,
+				pagedir->id);
+
+	if (rw_cleanup_modules(WRITE) && !error) {
+		abort_hibernate(TOI_FAILED_MODULE_CLEANUP,
+				"Failed to cleanup after writing.");
+		error = 1;
+	}
+
+	end_time = jiffies;
+
+	if ((end_time - start_time) && (!test_result_state(TOI_ABORTED))) {
+		toi_bkd.toi_io_time[0][0] += finish_at,
+		toi_bkd.toi_io_time[0][1] += (end_time - start_time);
+	}
+
+	return error;
+}
+
+/**
+ * read_pageset - highlevel function to read a pageset from disk
+ * @pagedir:			pageset to read
+ * @overwrittenpagesonly:	Whether to read the whole pageset or
+ *				only part of it.
+ *
+ * Returns:
+ *	Zero on success or -1 on failure.
+ **/
+static int read_pageset(struct pagedir *pagedir, int overwrittenpagesonly)
+{
+	int result = 0, base = 0;
+	int finish_at = pagedir->size;
+	int barmax = pagedir1.size + pagedir2.size;
+	struct memory_bitmap *pageflags;
+	unsigned long start_time, end_time;
+
+	if (pagedir->id == 1) {
+		toi_prepare_status(DONT_CLEAR_BAR,
+				"Reading kernel & process data...");
+		pageflags = pageset1_map;
+	} else {
+		toi_prepare_status(DONT_CLEAR_BAR, "Reading caches...");
+		if (overwrittenpagesonly) {
+			barmax = min(pagedir1.size, pagedir2.size);
+			finish_at = min(pagedir1.size, pagedir2.size);
+		} else
+			base = pagedir1.size;
+		pageflags = pageset2_map;
+	}
+
+	start_time = jiffies;
+
+	if (rw_init_modules(READ, pagedir->id)) {
+		toiActiveAllocator->remove_image();
+		result = 1;
+	} else
+		result = do_rw_loop(READ, finish_at, pageflags, base, barmax,
+				pagedir->id);
+
+	if (rw_cleanup_modules(READ) && !result) {
+		abort_hibernate(TOI_FAILED_MODULE_CLEANUP,
+				"Failed to cleanup after reading.");
+		result = 1;
+	}
+
+	/* Statistics */
+	end_time = jiffies;
+
+	if ((end_time - start_time) && (!test_result_state(TOI_ABORTED))) {
+		toi_bkd.toi_io_time[1][0] += finish_at,
+		toi_bkd.toi_io_time[1][1] += (end_time - start_time);
+	}
+
+	return result;
+}
+
+/**
+ * write_module_configs - store the modules configuration
+ *
+ * The configuration for each module is stored in the image header.
+ * Returns: Int
+ *	Zero on success, Error value otherwise.
+ **/
+static int write_module_configs(void)
+{
+	struct toi_module_ops *this_module;
+	char *buffer = (char *) toi_get_zeroed_page(22, TOI_ATOMIC_GFP);
+	int len, index = 1;
+	struct toi_module_header toi_module_header;
+
+	if (!buffer) {
+		printk(KERN_INFO "Failed to allocate a buffer for saving "
+				"module configuration info.\n");
+		return -ENOMEM;
+	}
+
+	/*
+	 * We have to know which data goes with which module, so we at
+	 * least write a length of zero for a module. Note that we are
+	 * also assuming every module's config data takes <= PAGE_SIZE.
+	 */
+
+	/* For each module (in registration order) */
+	list_for_each_entry(this_module, &toi_modules, module_list) {
+		if (!this_module->enabled || !this_module->storage_needed ||
+		    (this_module->type == WRITER_MODULE &&
+		     toiActiveAllocator != this_module))
+			continue;
+
+		/* Get the data from the module */
+		len = 0;
+		if (this_module->save_config_info)
+			len = this_module->save_config_info(buffer);
+
+		/* Save the details of the module */
+		toi_module_header.enabled = this_module->enabled;
+		toi_module_header.type = this_module->type;
+		toi_module_header.index = index++;
+		strncpy(toi_module_header.name, this_module->name,
+					sizeof(toi_module_header.name));
+		toiActiveAllocator->rw_header_chunk(WRITE,
+				this_module,
+				(char *) &toi_module_header,
+				sizeof(toi_module_header));
+
+		/* Save the size of the data and any data returned */
+		toiActiveAllocator->rw_header_chunk(WRITE,
+				this_module,
+				(char *) &len, sizeof(int));
+		if (len)
+			toiActiveAllocator->rw_header_chunk(
+				WRITE, this_module, buffer, len);
+	}
+
+	/* Write a blank header to terminate the list */
+	toi_module_header.name[0] = '\0';
+	toiActiveAllocator->rw_header_chunk(WRITE, NULL,
+			(char *) &toi_module_header, sizeof(toi_module_header));
+
+	toi_free_page(22, (unsigned long) buffer);
+	return 0;
+}
+
+/**
+ * read_one_module_config - read and configure one module
+ *
+ * Read the configuration for one module, and configure the module
+ * to match if it is loaded.
+ *
+ * Returns: Int
+ *	Zero on success, Error value otherwise.
+ **/
+static int read_one_module_config(struct toi_module_header *header)
+{
+	struct toi_module_ops *this_module;
+	int result, len;
+	char *buffer;
+
+	/* Find the module */
+	this_module = toi_find_module_given_name(header->name);
+
+	if (!this_module) {
+		if (header->enabled) {
+			toi_early_boot_message(1, TOI_CONTINUE_REQ,
+				"It looks like we need module %s for reading "
+				"the image but it hasn't been registered.\n",
+				header->name);
+			if (!(test_toi_state(TOI_CONTINUE_REQ)))
+				return -EINVAL;
+		} else
+			printk(KERN_INFO "Module %s configuration data found, "
+				"but the module hasn't registered. Looks like "
+				"it was disabled, so we're ignoring its data.",
+				header->name);
+	}
+
+	/* Get the length of the data (if any) */
+	result = toiActiveAllocator->rw_header_chunk(READ, NULL, (char *) &len,
+			sizeof(int));
+	if (result) {
+		printk(KERN_ERR "Failed to read the length of the module %s's"
+				" configuration data.\n",
+				header->name);
+		return -EINVAL;
+	}
+
+	/* Read any data and pass to the module (if we found one) */
+	if (!len)
+		return 0;
+
+	buffer = (char *) toi_get_zeroed_page(23, TOI_ATOMIC_GFP);
+
+	if (!buffer) {
+		printk(KERN_ERR "Failed to allocate a buffer for reloading "
+				"module configuration info.\n");
+		return -ENOMEM;
+	}
+
+	toiActiveAllocator->rw_header_chunk(READ, NULL, buffer, len);
+
+	if (!this_module)
+		goto out;
+
+	if (!this_module->save_config_info)
+		printk(KERN_ERR "Huh? Module %s appears to have a "
+				"save_config_info, but not a load_config_info "
+				"function!\n", this_module->name);
+	else
+		this_module->load_config_info(buffer, len);
+
+	/*
+	 * Now move this module to the tail of its lists. This will put it in
+	 * order. Any new modules will end up at the top of the lists. They
+	 * should have been set to disabled when loaded (people will
+	 * normally not edit an initrd to load a new module and then hibernate
+	 * without using it!).
+	 */
+
+	toi_move_module_tail(this_module);
+
+	this_module->enabled = header->enabled;
+
+out:
+	toi_free_page(23, (unsigned long) buffer);
+	return 0;
+}
+
+/**
+ * read_module_configs - reload module configurations from the image header.
+ *
+ * Returns: Int
+ *	Zero on success or an error code.
+ **/
+static int read_module_configs(void)
+{
+	int result = 0;
+	struct toi_module_header toi_module_header;
+	struct toi_module_ops *this_module;
+
+	/* All modules are initially disabled. That way, if we have a module
+	 * loaded now that wasn't loaded when we hibernated, it won't be used
+	 * in trying to read the data.
+	 */
+	list_for_each_entry(this_module, &toi_modules, module_list)
+		this_module->enabled = 0;
+
+	/* Get the first module header */
+	result = toiActiveAllocator->rw_header_chunk(READ, NULL,
+			(char *) &toi_module_header,
+			sizeof(toi_module_header));
+	if (result) {
+		printk(KERN_ERR "Failed to read the next module header.\n");
+		return -EINVAL;
+	}
+
+	/* For each module (in registration order) */
+	while (toi_module_header.name[0]) {
+		result = read_one_module_config(&toi_module_header);
+
+		if (result)
+			return -EINVAL;
+
+		/* Get the next module header */
+		result = toiActiveAllocator->rw_header_chunk(READ, NULL,
+				(char *) &toi_module_header,
+				sizeof(toi_module_header));
+
+		if (result) {
+			printk(KERN_ERR "Failed to read the next module "
+					"header.\n");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static inline int save_fs_info(struct fs_info *fs, struct block_device *bdev)
+{
+	return (!fs || IS_ERR(fs) || !fs->last_mount_size) ? 0 : 1;
+}
+
+int fs_info_space_needed(void)
+{
+	const struct super_block *sb;
+	int result = sizeof(int);
+
+	list_for_each_entry(sb, &super_blocks, s_list) {
+		struct fs_info *fs;
+
+		if (!sb->s_bdev)
+			continue;
+
+		fs = fs_info_from_block_dev(sb->s_bdev);
+		if (save_fs_info(fs, sb->s_bdev))
+			result += 16 + sizeof(dev_t) + sizeof(int) +
+				fs->last_mount_size;
+		free_fs_info(fs);
+	}
+	return result;
+}
+
+static int fs_info_num_to_save(void)
+{
+	const struct super_block *sb;
+	int to_save = 0;
+
+	list_for_each_entry(sb, &super_blocks, s_list) {
+		struct fs_info *fs;
+
+		if (!sb->s_bdev)
+			continue;
+
+		fs = fs_info_from_block_dev(sb->s_bdev);
+		if (save_fs_info(fs, sb->s_bdev))
+			to_save++;
+		free_fs_info(fs);
+	}
+
+	return to_save;
+}
+
+static int fs_info_save(void)
+{
+	const struct super_block *sb;
+	int to_save = fs_info_num_to_save();
+
+	if (toiActiveAllocator->rw_header_chunk(WRITE, NULL, (char *) &to_save,
+				sizeof(int))) {
+		abort_hibernate(TOI_FAILED_IO, "Failed to write num fs_info"
+				" to save.");
+		return -EIO;
+	}
+
+	list_for_each_entry(sb, &super_blocks, s_list) {
+		struct fs_info *fs;
+
+		if (!sb->s_bdev)
+			continue;
+
+		fs = fs_info_from_block_dev(sb->s_bdev);
+		if (save_fs_info(fs, sb->s_bdev)) {
+			if (toiActiveAllocator->rw_header_chunk(WRITE, NULL,
+					&fs->uuid[0], 16)) {
+				abort_hibernate(TOI_FAILED_IO, "Failed to "
+						"write uuid.");
+				return -EIO;
+			}
+			if (toiActiveAllocator->rw_header_chunk(WRITE, NULL,
+					(char *) &fs->dev_t, sizeof(dev_t))) {
+				abort_hibernate(TOI_FAILED_IO, "Failed to "
+						"write dev_t.");
+				return -EIO;
+			}
+			if (toiActiveAllocator->rw_header_chunk(WRITE, NULL,
+					(char *) &fs->last_mount_size, sizeof(int))) {
+				abort_hibernate(TOI_FAILED_IO, "Failed to "
+						"write last mount length.");
+				return -EIO;
+			}
+			if (toiActiveAllocator->rw_header_chunk(WRITE, NULL,
+					fs->last_mount, fs->last_mount_size)) {
+				abort_hibernate(TOI_FAILED_IO, "Failed to "
+						"write uuid.");
+				return -EIO;
+			}
+		}
+		free_fs_info(fs);
+	}
+	return 0;
+}
+
+static int fs_info_load_and_check_one(void)
+{
+	char uuid[16], *last_mount;
+	int result = 0, ln;
+	dev_t dev_t;
+	struct block_device *dev;
+	struct fs_info *fs_info, seek;
+
+	if (toiActiveAllocator->rw_header_chunk(READ, NULL, uuid, 16)) {
+		abort_hibernate(TOI_FAILED_IO, "Failed to read uuid.");
+		return -EIO;
+	}
+
+	read_if_version(3, dev_t, "uuid dev_t field", return -EIO);
+
+	if (toiActiveAllocator->rw_header_chunk(READ, NULL, (char *) &ln,
+				sizeof(int))) {
+		abort_hibernate(TOI_FAILED_IO,
+				"Failed to read last mount size.");
+		return -EIO;
+	}
+
+	last_mount = kzalloc(ln, GFP_KERNEL);
+
+	if (!last_mount)
+		return -ENOMEM;
+
+	if (toiActiveAllocator->rw_header_chunk(READ, NULL, last_mount,	ln)) {
+		abort_hibernate(TOI_FAILED_IO,
+				"Failed to read last mount timestamp.");
+		result = -EIO;
+		goto out_lmt;
+	}
+
+	strncpy((char *) &seek.uuid, uuid, 16);
+	seek.dev_t = dev_t;
+	seek.last_mount_size = ln;
+	seek.last_mount = last_mount;
+	dev_t = blk_lookup_fs_info(&seek);
+	if (!dev_t)
+		goto out_lmt;
+
+	dev = toi_open_by_devnum(dev_t);
+
+	fs_info = fs_info_from_block_dev(dev);
+	if (fs_info && !IS_ERR(fs_info)) {
+		if (ln != fs_info->last_mount_size) {
+			printk(KERN_EMERG "Found matching uuid but last mount "
+					"time lengths differ?! "
+					"(%d vs %d).\n", ln,
+					fs_info->last_mount_size);
+			result = -EINVAL;
+		} else {
+			char buf[BDEVNAME_SIZE];
+			result = !!memcmp(fs_info->last_mount, last_mount, ln);
+			if (result)
+				printk(KERN_EMERG "Last mount time for %s has "
+					"changed!\n", bdevname(dev, buf));
+		}
+	}
+	toi_close_bdev(dev);
+	free_fs_info(fs_info);
+out_lmt:
+	kfree(last_mount);
+	return result;
+}
+
+static int fs_info_load_and_check(void)
+{
+	int to_do, result = 0;
+
+	if (toiActiveAllocator->rw_header_chunk(READ, NULL, (char *) &to_do,
+				sizeof(int))) {
+		abort_hibernate(TOI_FAILED_IO, "Failed to read num fs_info "
+				"to load.");
+		return -EIO;
+	}
+
+	while(to_do--)
+		result |= fs_info_load_and_check_one();
+
+	return result;
+}
+
+/**
+ * write_image_header - write the image header after write the image proper
+ *
+ * Returns: Int
+ *	Zero on success, error value otherwise.
+ **/
+int write_image_header(void)
+{
+	int ret;
+	int total = pagedir1.size + pagedir2.size+2;
+	char *header_buffer = NULL;
+
+	/* Now prepare to write the header */
+	ret = toiActiveAllocator->write_header_init();
+	if (ret) {
+		abort_hibernate(TOI_FAILED_MODULE_INIT,
+				"Active allocator's write_header_init"
+				" function failed.");
+		goto write_image_header_abort;
+	}
+
+	/* Get a buffer */
+	header_buffer = (char *) toi_get_zeroed_page(24, TOI_ATOMIC_GFP);
+	if (!header_buffer) {
+		abort_hibernate(TOI_OUT_OF_MEMORY,
+			"Out of memory when trying to get page for header!");
+		goto write_image_header_abort;
+	}
+
+	/* Write hibernate header */
+	if (fill_toi_header((struct toi_header *) header_buffer)) {
+		abort_hibernate(TOI_OUT_OF_MEMORY,
+			"Failure to fill header information!");
+		goto write_image_header_abort;
+	}
+
+	if (toiActiveAllocator->rw_header_chunk(WRITE, NULL,
+			header_buffer, sizeof(struct toi_header))) {
+		abort_hibernate(TOI_OUT_OF_MEMORY,
+			"Failure to write header info.");
+		goto write_image_header_abort;
+	}
+
+	if (toiActiveAllocator->rw_header_chunk(WRITE, NULL,
+			(char *) &toi_max_workers, sizeof(toi_max_workers))) {
+		abort_hibernate(TOI_OUT_OF_MEMORY,
+			"Failure to number of workers to use.");
+		goto write_image_header_abort;
+	}
+
+	/* Write filesystem info */
+	if (fs_info_save())
+		goto write_image_header_abort;
+
+	/* Write module configurations */
+	ret = write_module_configs();
+	if (ret) {
+		abort_hibernate(TOI_FAILED_IO,
+				"Failed to write module configs.");
+		goto write_image_header_abort;
+	}
+
+	if (memory_bm_write(pageset1_map,
+				toiActiveAllocator->rw_header_chunk)) {
+		abort_hibernate(TOI_FAILED_IO,
+				"Failed to write bitmaps.");
+		goto write_image_header_abort;
+	}
+
+	/* Flush data and let allocator cleanup */
+	if (toiActiveAllocator->write_header_cleanup()) {
+		abort_hibernate(TOI_FAILED_IO,
+				"Failed to cleanup writing header.");
+		goto write_image_header_abort_no_cleanup;
+	}
+
+	if (test_result_state(TOI_ABORTED))
+		goto write_image_header_abort_no_cleanup;
+
+	toi_update_status(total, total, NULL);
+
+out:
+	if (header_buffer)
+		toi_free_page(24, (unsigned long) header_buffer);
+	return ret;
+
+write_image_header_abort:
+	toiActiveAllocator->write_header_cleanup();
+write_image_header_abort_no_cleanup:
+	ret = -1;
+	goto out;
+}
+
+/**
+ * sanity_check - check the header
+ * @sh:	the header which was saved at hibernate time.
+ *
+ * Perform a few checks, seeking to ensure that the kernel being
+ * booted matches the one hibernated. They need to match so we can
+ * be _sure_ things will work. It is not absolutely impossible for
+ * resuming from a different kernel to work, just not assured.
+ **/
+static char *sanity_check(struct toi_header *sh)
+{
+	char *reason = check_image_kernel((struct swsusp_info *) sh);
+
+	if (reason)
+		return reason;
+
+	if (!test_action_state(TOI_IGNORE_ROOTFS)) {
+		const struct super_block *sb;
+		list_for_each_entry(sb, &super_blocks, s_list) {
+			if ((!(sb->s_flags & MS_RDONLY)) &&
+			    (sb->s_type->fs_flags & FS_REQUIRES_DEV))
+				return "Device backed fs has been mounted "
+					"rw prior to resume or initrd/ramfs "
+					"is mounted rw.";
+		}
+	}
+
+	return NULL;
+}
+
+static DECLARE_WAIT_QUEUE_HEAD(freeze_wait);
+
+#define FREEZE_IN_PROGRESS (~0)
+
+static int freeze_result;
+
+static void do_freeze(struct work_struct *dummy)
+{
+	freeze_result = freeze_processes();
+	wake_up(&freeze_wait);
+	trap_non_toi_io = 1;
+}
+
+static DECLARE_WORK(freeze_work, do_freeze);
+
+/**
+ * __read_pageset1 - test for the existence of an image and attempt to load it
+ *
+ * Returns:	Int
+ *	Zero if image found and pageset1 successfully loaded.
+ *	Error if no image found or loaded.
+ **/
+static int __read_pageset1(void)
+{
+	int i, result = 0;
+	char *header_buffer = (char *) toi_get_zeroed_page(25, TOI_ATOMIC_GFP),
+	     *sanity_error = NULL;
+	struct toi_header *toi_header;
+
+	if (!header_buffer) {
+		printk(KERN_INFO "Unable to allocate a page for reading the "
+				"signature.\n");
+		return -ENOMEM;
+	}
+
+	/* Check for an image */
+	result = toiActiveAllocator->image_exists(1);
+	if (result == 3) {
+		result = -ENODATA;
+		toi_early_boot_message(1, 0, "The signature from an older "
+				"version of TuxOnIce has been detected.");
+		goto out_remove_image;
+	}
+
+	if (result != 1) {
+		result = -ENODATA;
+		noresume_reset_modules();
+		printk(KERN_INFO "TuxOnIce: No image found.\n");
+		goto out;
+	}
+
+	/*
+	 * Prepare the active allocator for reading the image header. The
+	 * activate allocator might read its own configuration.
+	 *
+	 * NB: This call may never return because there might be a signature
+	 * for a different image such that we warn the user and they choose
+	 * to reboot. (If the device ids look erroneous (2.4 vs 2.6) or the
+	 * location of the image might be unavailable if it was stored on a
+	 * network connection).
+	 */
+
+	result = toiActiveAllocator->read_header_init();
+	if (result) {
+		printk(KERN_INFO "TuxOnIce: Failed to initialise, reading the "
+				"image header.\n");
+		goto out_remove_image;
+	}
+
+	/* Check for noresume command line option */
+	if (test_toi_state(TOI_NORESUME_SPECIFIED)) {
+		printk(KERN_INFO "TuxOnIce: Noresume on command line. Removed "
+				"image.\n");
+		goto out_remove_image;
+	}
+
+	/* Check whether we've resumed before */
+	if (test_toi_state(TOI_RESUMED_BEFORE)) {
+		toi_early_boot_message(1, 0, NULL);
+		if (!(test_toi_state(TOI_CONTINUE_REQ))) {
+			printk(KERN_INFO "TuxOnIce: Tried to resume before: "
+					"Invalidated image.\n");
+			goto out_remove_image;
+		}
+	}
+
+	clear_toi_state(TOI_CONTINUE_REQ);
+
+	toi_image_header_version = toiActiveAllocator->get_header_version();
+
+	if (unlikely(toi_image_header_version > TOI_HEADER_VERSION)) {
+		toi_early_boot_message(1, 0, image_version_error);
+		if (!(test_toi_state(TOI_CONTINUE_REQ))) {
+			printk(KERN_INFO "TuxOnIce: Header version too new: "
+					"Invalidated image.\n");
+			goto out_remove_image;
+		}
+	}
+
+	/* Read hibernate header */
+	result = toiActiveAllocator->rw_header_chunk(READ, NULL,
+			header_buffer, sizeof(struct toi_header));
+	if (result < 0) {
+		printk(KERN_ERR "TuxOnIce: Failed to read the image "
+				"signature.\n");
+		goto out_remove_image;
+	}
+
+	toi_header = (struct toi_header *) header_buffer;
+
+	/*
+	 * NB: This call may also result in a reboot rather than returning.
+	 */
+
+	sanity_error = sanity_check(toi_header);
+	if (sanity_error) {
+		toi_early_boot_message(1, TOI_CONTINUE_REQ,
+				sanity_error);
+		printk(KERN_INFO "TuxOnIce: Sanity check failed.\n");
+		goto out_remove_image;
+	}
+
+	/*
+	 * We have an image and it looks like it will load okay.
+	 *
+	 * Get metadata from header. Don't override commandline parameters.
+	 *
+	 * We don't need to save the image size limit because it's not used
+	 * during resume and will be restored with the image anyway.
+	 */
+
+	memcpy((char *) &pagedir1,
+		(char *) &toi_header->pagedir, sizeof(pagedir1));
+	toi_result = toi_header->param0;
+	if (!toi_bkd.toi_debug_state) {
+		toi_bkd.toi_action =
+			(toi_header->param1 & ~toi_bootflags_mask) |
+			(toi_bkd.toi_action & toi_bootflags_mask);
+		toi_bkd.toi_debug_state = toi_header->param2;
+		toi_bkd.toi_default_console_level = toi_header->param3;
+	}
+	clear_toi_state(TOI_IGNORE_LOGLEVEL);
+	pagedir2.size = toi_header->pageset_2_size;
+	for (i = 0; i < 4; i++)
+		toi_bkd.toi_io_time[i/2][i%2] =
+			toi_header->io_time[i/2][i%2];
+
+	set_toi_state(TOI_BOOT_KERNEL);
+	boot_kernel_data_buffer = toi_header->bkd;
+
+	read_if_version(1, toi_max_workers, "TuxOnIce max workers",
+			goto out_remove_image);
+
+	/* Read filesystem info */
+	if (fs_info_load_and_check()) {
+		printk(KERN_EMERG "TuxOnIce: File system mount time checks "
+			"failed. Refusing to corrupt your filesystems!\n");
+		goto out_remove_image;
+	}
+
+	/* Read module configurations */
+	result = read_module_configs();
+	if (result) {
+		pagedir1.size = 0;
+		pagedir2.size = 0;
+		printk(KERN_INFO "TuxOnIce: Failed to read TuxOnIce module "
+				"configurations.\n");
+		clear_action_state(TOI_KEEP_IMAGE);
+		goto out_remove_image;
+	}
+
+	toi_prepare_console();
+
+	set_toi_state(TOI_NOW_RESUMING);
+
+	result = pm_notifier_call_chain(PM_RESTORE_PREPARE);
+	if (result)
+		goto out_notifier_call_chain;;
+
+	if (usermodehelper_disable())
+		goto out_enable_usermodehelper;
+
+	current->flags |= PF_NOFREEZE;
+	freeze_result = FREEZE_IN_PROGRESS;
+
+	schedule_work_on(cpumask_first(cpu_online_mask), &freeze_work);
+
+	toi_cond_pause(1, "About to read original pageset1 locations.");
+
+	/*
+	 * See _toi_rw_header_chunk in tuxonice_bio.c:
+	 * Initialize pageset1_map by reading the map from the image.
+	 */
+	if (memory_bm_read(pageset1_map, toiActiveAllocator->rw_header_chunk))
+		goto out_thaw;
+
+	/*
+	 * See toi_rw_cleanup in tuxonice_bio.c:
+	 * Clean up after reading the header.
+	 */
+	result = toiActiveAllocator->read_header_cleanup();
+	if (result) {
+		printk(KERN_ERR "TuxOnIce: Failed to cleanup after reading the "
+				"image header.\n");
+		goto out_thaw;
+	}
+
+	toi_cond_pause(1, "About to read pagedir.");
+
+	/*
+	 * Get the addresses of pages into which we will load the kernel to
+	 * be copied back and check if they conflict with the ones we are using.
+	 */
+	if (toi_get_pageset1_load_addresses()) {
+		printk(KERN_INFO "TuxOnIce: Failed to get load addresses for "
+				"pageset1.\n");
+		goto out_thaw;
+	}
+
+	/* Read the original kernel back */
+	toi_cond_pause(1, "About to read pageset 1.");
+
+	/* Given the pagemap, read back the data from disk */
+	if (read_pageset(&pagedir1, 0)) {
+		toi_prepare_status(DONT_CLEAR_BAR, "Failed to read pageset 1.");
+		result = -EIO;
+		goto out_thaw;
+	}
+
+	toi_cond_pause(1, "About to restore original kernel.");
+	result = 0;
+
+	if (!toi_keeping_image &&
+	    toiActiveAllocator->mark_resume_attempted)
+		toiActiveAllocator->mark_resume_attempted(1);
+
+	wait_event(freeze_wait, freeze_result != FREEZE_IN_PROGRESS);
+out:
+	current->flags &= ~PF_NOFREEZE;
+	toi_free_page(25, (unsigned long) header_buffer);
+	return result;
+
+out_thaw:
+	wait_event(freeze_wait, freeze_result != FREEZE_IN_PROGRESS);
+	trap_non_toi_io = 0;
+	thaw_processes();
+out_enable_usermodehelper:
+	usermodehelper_enable();
+out_notifier_call_chain:
+        pm_notifier_call_chain(PM_POST_RESTORE);
+	toi_cleanup_console();
+out_remove_image:
+	result = -EINVAL;
+	if (!toi_keeping_image)
+		toiActiveAllocator->remove_image();
+	toiActiveAllocator->read_header_cleanup();
+	noresume_reset_modules();
+	goto out;
+}
+
+/**
+ * read_pageset1 - highlevel function to read the saved pages
+ *
+ * Attempt to read the header and pageset1 of a hibernate image.
+ * Handle the outcome, complaining where appropriate.
+ **/
+int read_pageset1(void)
+{
+	int error;
+
+	error = __read_pageset1();
+
+	if (error && error != -ENODATA && error != -EINVAL &&
+					!test_result_state(TOI_ABORTED))
+		abort_hibernate(TOI_IMAGE_ERROR,
+			"TuxOnIce: Error %d resuming\n", error);
+
+	return error;
+}
+
+/**
+ * get_have_image_data - check the image header
+ **/
+static char *get_have_image_data(void)
+{
+	char *output_buffer = (char *) toi_get_zeroed_page(26, TOI_ATOMIC_GFP);
+	struct toi_header *toi_header;
+
+	if (!output_buffer) {
+		printk(KERN_INFO "Output buffer null.\n");
+		return NULL;
+	}
+
+	/* Check for an image */
+	if (!toiActiveAllocator->image_exists(1) ||
+	    toiActiveAllocator->read_header_init() ||
+	    toiActiveAllocator->rw_header_chunk(READ, NULL,
+			output_buffer, sizeof(struct toi_header))) {
+		sprintf(output_buffer, "0\n");
+		/*
+		 * From an initrd/ramfs, catting have_image and
+		 * getting a result of 0 is sufficient.
+		 */
+		clear_toi_state(TOI_BOOT_TIME);
+		goto out;
+	}
+
+	toi_header = (struct toi_header *) output_buffer;
+
+	sprintf(output_buffer, "1\n%s\n%s\n",
+			toi_header->uts.machine,
+			toi_header->uts.version);
+
+	/* Check whether we've resumed before */
+	if (test_toi_state(TOI_RESUMED_BEFORE))
+		strcat(output_buffer, "Resumed before.\n");
+
+out:
+	noresume_reset_modules();
+	return output_buffer;
+}
+
+/**
+ * read_pageset2 - read second part of the image
+ * @overwrittenpagesonly:	Read only pages which would have been
+ *				verwritten by pageset1?
+ *
+ * Read in part or all of pageset2 of an image, depending upon
+ * whether we are hibernating and have only overwritten a portion
+ * with pageset1 pages, or are resuming and need to read them
+ * all.
+ *
+ * Returns: Int
+ *	Zero if no error, otherwise the error value.
+ **/
+int read_pageset2(int overwrittenpagesonly)
+{
+	int result = 0;
+
+	if (!pagedir2.size)
+		return 0;
+
+	result = read_pageset(&pagedir2, overwrittenpagesonly);
+
+	toi_cond_pause(1, "Pagedir 2 read.");
+
+	return result;
+}
+
+/**
+ * image_exists_read - has an image been found?
+ * @page:	Output buffer
+ *
+ * Store 0 or 1 in page, depending on whether an image is found.
+ * Incoming buffer is PAGE_SIZE and result is guaranteed
+ * to be far less than that, so we don't worry about
+ * overflow.
+ **/
+int image_exists_read(const char *page, int count)
+{
+	int len = 0;
+	char *result;
+
+	if (toi_activate_storage(0))
+		return count;
+
+	if (!test_toi_state(TOI_RESUME_DEVICE_OK))
+		toi_attempt_to_parse_resume_device(0);
+
+	if (!toiActiveAllocator) {
+		len = sprintf((char *) page, "-1\n");
+	} else {
+		result = get_have_image_data();
+		if (result) {
+			len = sprintf((char *) page, "%s",  result);
+			toi_free_page(26, (unsigned long) result);
+		}
+	}
+
+	toi_deactivate_storage(0);
+
+	return len;
+}
+
+/**
+ * image_exists_write - invalidate an image if one exists
+ **/
+int image_exists_write(const char *buffer, int count)
+{
+	if (toi_activate_storage(0))
+		return count;
+
+	if (toiActiveAllocator && toiActiveAllocator->image_exists(1))
+		toiActiveAllocator->remove_image();
+
+	toi_deactivate_storage(0);
+
+	clear_result_state(TOI_KEPT_IMAGE);
+
+	return count;
+}