Initial import

1 files changed, 474 insertions, 0 deletions

diff --git a/kernel/power/tuxonice_swap.c b/kernel/power/tuxonice_swap.c
new file mode 100644
index 000000000..ce3215033
--- /dev/null
+++ b/kernel/power/tuxonice_swap.c
@@ -0,0 +1,474 @@
+/*
+ * kernel/power/tuxonice_swap.c
+ *
+ * Copyright (C) 2004-2015 Nigel Cunningham (nigel at nigelcunningham com au)
+ *
+ * Distributed under GPLv2.
+ *
+ * This file encapsulates functions for usage of swap space as a
+ * backing store.
+ */
+
+#include <linux/suspend.h>
+#include <linux/blkdev.h>
+#include <linux/swapops.h>
+#include <linux/swap.h>
+#include <linux/syscalls.h>
+#include <linux/fs_uuid.h>
+
+#include "tuxonice.h"
+#include "tuxonice_sysfs.h"
+#include "tuxonice_modules.h"
+#include "tuxonice_io.h"
+#include "tuxonice_ui.h"
+#include "tuxonice_extent.h"
+#include "tuxonice_bio.h"
+#include "tuxonice_alloc.h"
+#include "tuxonice_builtin.h"
+
+static struct toi_module_ops toi_swapops;
+
+/* For swapfile automatically swapon/off'd. */
+static char swapfilename[255] = "";
+static int toi_swapon_status;
+
+/* Swap Pages */
+static unsigned long swap_allocated;
+
+static struct sysinfo swapinfo;
+
+static int is_ram_backed(struct swap_info_struct *si)
+{
+	if (!strncmp(si->bdev->bd_disk->disk_name, "ram", 3) ||
+	    !strncmp(si->bdev->bd_disk->disk_name, "zram", 4))
+		return 1;
+
+	return 0;
+}
+
+/**
+ * enable_swapfile: Swapon the user specified swapfile prior to hibernating.
+ *
+ * Activate the given swapfile if it wasn't already enabled. Remember whether
+ * we really did swapon it for swapoffing later.
+ */
+static void enable_swapfile(void)
+{
+	int activateswapresult = -EINVAL;
+
+	if (swapfilename[0]) {
+		/* Attempt to swap on with maximum priority */
+		activateswapresult = sys_swapon(swapfilename, 0xFFFF);
+		if (activateswapresult && activateswapresult != -EBUSY)
+			printk(KERN_ERR "TuxOnIce: The swapfile/partition "
+				"specified by /sys/power/tuxonice/swap/swapfile"
+				" (%s) could not be turned on (error %d). "
+				"Attempting to continue.\n",
+				swapfilename, activateswapresult);
+		if (!activateswapresult)
+			toi_swapon_status = 1;
+	}
+}
+
+/**
+ * disable_swapfile: Swapoff any file swaponed at the start of the cycle.
+ *
+ * If we did successfully swapon a file at the start of the cycle, swapoff
+ * it now (finishing up).
+ */
+static void disable_swapfile(void)
+{
+	if (!toi_swapon_status)
+		return;
+
+	sys_swapoff(swapfilename);
+	toi_swapon_status = 0;
+}
+
+static int add_blocks_to_extent_chain(struct toi_bdev_info *chain,
+		unsigned long start, unsigned long end)
+{
+	if (test_action_state(TOI_TEST_BIO))
+		toi_message(TOI_IO, TOI_VERBOSE, 0, "Adding extent %lu-%lu to "
+				"chain %p.", start << chain->bmap_shift,
+				end << chain->bmap_shift, chain);
+
+	return toi_add_to_extent_chain(&chain->blocks, start, end);
+}
+
+
+static int get_main_pool_phys_params(struct toi_bdev_info *chain)
+{
+	struct hibernate_extent *extentpointer = NULL;
+	unsigned long address, extent_min = 0, extent_max = 0;
+	int empty = 1;
+
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "get main pool phys params for "
+			"chain %d.", chain->allocator_index);
+
+	if (!chain->allocations.first)
+		return 0;
+
+	if (chain->blocks.first)
+		toi_put_extent_chain(&chain->blocks);
+
+	toi_extent_for_each(&chain->allocations, extentpointer, address) {
+		swp_entry_t swap_address = (swp_entry_t) { address };
+		struct block_device *bdev;
+		sector_t new_sector = map_swap_entry(swap_address, &bdev);
+
+		if (empty) {
+			empty = 0;
+			extent_min = extent_max = new_sector;
+			continue;
+		}
+
+		if (new_sector == extent_max + 1) {
+			extent_max++;
+			continue;
+		}
+
+		if (add_blocks_to_extent_chain(chain, extent_min, extent_max)) {
+			printk(KERN_ERR "Out of memory while making block "
+					"chains.\n");
+			return -ENOMEM;
+		}
+
+		extent_min = new_sector;
+		extent_max = new_sector;
+	}
+
+	if (!empty &&
+	    add_blocks_to_extent_chain(chain, extent_min, extent_max)) {
+		printk(KERN_ERR "Out of memory while making block chains.\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/*
+ * Like si_swapinfo, except that we don't include ram backed swap (compcache!)
+ * and don't need to use the spinlocks (userspace is stopped when this
+ * function is called).
+ */
+void si_swapinfo_no_compcache(void)
+{
+	unsigned int i;
+
+	si_swapinfo(&swapinfo);
+	swapinfo.freeswap = 0;
+	swapinfo.totalswap = 0;
+
+	for (i = 0; i < MAX_SWAPFILES; i++) {
+		struct swap_info_struct *si = get_swap_info_struct(i);
+		if (si && (si->flags & SWP_WRITEOK) && !is_ram_backed(si)) {
+			swapinfo.totalswap += si->inuse_pages;
+			swapinfo.freeswap += si->pages - si->inuse_pages;
+		}
+	}
+}
+/*
+ * We can't just remember the value from allocation time, because other
+ * processes might have allocated swap in the mean time.
+ */
+static unsigned long toi_swap_storage_available(void)
+{
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "In toi_swap_storage_available.");
+	si_swapinfo_no_compcache();
+	return swapinfo.freeswap + swap_allocated;
+}
+
+static int toi_swap_initialise(int starting_cycle)
+{
+	if (!starting_cycle)
+		return 0;
+
+	enable_swapfile();
+	return 0;
+}
+
+static void toi_swap_cleanup(int ending_cycle)
+{
+	if (!ending_cycle)
+		return;
+
+	disable_swapfile();
+}
+
+static void toi_swap_free_storage(struct toi_bdev_info *chain)
+{
+	/* Free swap entries */
+	struct hibernate_extent *extentpointer;
+	unsigned long extentvalue;
+
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "Freeing storage for chain %p.",
+			chain);
+
+	swap_allocated -= chain->allocations.size;
+	toi_extent_for_each(&chain->allocations, extentpointer, extentvalue)
+		swap_free((swp_entry_t) { extentvalue });
+
+	toi_put_extent_chain(&chain->allocations);
+}
+
+static void free_swap_range(unsigned long min, unsigned long max)
+{
+	int j;
+
+	for (j = min; j <= max; j++)
+		swap_free((swp_entry_t) { j });
+	swap_allocated -= (max - min + 1);
+}
+
+/*
+ * Allocation of a single swap type. Swap priorities are handled at the higher
+ * level.
+ */
+static int toi_swap_allocate_storage(struct toi_bdev_info *chain,
+		unsigned long request)
+{
+	unsigned long gotten = 0;
+
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "  Swap allocate storage: Asked to"
+			" allocate %lu pages from device %d.", request,
+			chain->allocator_index);
+
+	while (gotten < request) {
+		swp_entry_t start, end;
+                if (0) {
+                    /* Broken at the moment for SSDs */
+                    get_swap_range_of_type(chain->allocator_index, &start, &end,
+                            request - gotten + 1);
+                } else {
+                    start = end = get_swap_page_of_type(chain->allocator_index);
+                }
+		if (start.val) {
+			int added = end.val - start.val + 1;
+			if (toi_add_to_extent_chain(&chain->allocations,
+						start.val, end.val)) {
+				printk(KERN_INFO "Failed to allocate extent for "
+					"%lu-%lu.\n", start.val, end.val);
+				free_swap_range(start.val, end.val);
+				break;
+			}
+			gotten += added;
+			swap_allocated += added;
+		} else
+			break;
+	}
+
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "  Allocated %lu pages.", gotten);
+	return gotten;
+}
+
+static int toi_swap_register_storage(void)
+{
+	int i, result = 0;
+
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "toi_swap_register_storage.");
+	for (i = 0; i < MAX_SWAPFILES; i++) {
+		struct swap_info_struct *si = get_swap_info_struct(i);
+		struct toi_bdev_info *devinfo;
+		unsigned char *p;
+		unsigned char buf[256];
+		struct fs_info *fs_info;
+
+		if (!si || !(si->flags & SWP_WRITEOK) || is_ram_backed(si))
+			continue;
+
+		devinfo = toi_kzalloc(39, sizeof(struct toi_bdev_info),
+				GFP_ATOMIC);
+		if (!devinfo) {
+			printk("Failed to allocate devinfo struct for swap "
+					"device %d.\n", i);
+			return -ENOMEM;
+		}
+
+		devinfo->bdev = si->bdev;
+		devinfo->allocator = &toi_swapops;
+		devinfo->allocator_index = i;
+
+		fs_info = fs_info_from_block_dev(si->bdev);
+		if (fs_info && !IS_ERR(fs_info)) {
+			memcpy(devinfo->uuid, &fs_info->uuid, 16);
+			free_fs_info(fs_info);
+		} else
+			result = (int) PTR_ERR(fs_info);
+
+		if (!fs_info)
+			printk("fs_info from block dev returned %d.\n", result);
+		devinfo->dev_t = si->bdev->bd_dev;
+		devinfo->prio = si->prio;
+		devinfo->bmap_shift = 3;
+		devinfo->blocks_per_page = 1;
+
+		p = d_path(&si->swap_file->f_path, buf, sizeof(buf));
+		sprintf(devinfo->name, "swap on %s", p);
+
+		toi_message(TOI_IO, TOI_VERBOSE, 0, "Registering swap storage:"
+				" Device %d (%lx), prio %d.", i,
+				(unsigned long) devinfo->dev_t, devinfo->prio);
+		toi_bio_ops.register_storage(devinfo);
+	}
+
+	return 0;
+}
+
+static unsigned long toi_swap_free_unused_storage(struct toi_bdev_info *chain, unsigned long used)
+{
+    struct hibernate_extent *extentpointer = NULL;
+    unsigned long extentvalue;
+    unsigned long i = 0, first_freed = 0;
+
+    toi_extent_for_each(&chain->allocations, extentpointer, extentvalue) {
+        i++;
+        if (i > used) {
+            swap_free((swp_entry_t) { extentvalue });
+            if (!first_freed)
+                first_freed = extentvalue;
+        }
+    }
+
+    return first_freed;
+}
+
+/*
+ * workspace_size
+ *
+ * Description:
+ * Returns the number of bytes of RAM needed for this
+ * code to do its work. (Used when calculating whether
+ * we have enough memory to be able to hibernate & resume).
+ *
+ */
+static int toi_swap_memory_needed(void)
+{
+	return 1;
+}
+
+/*
+ * Print debug info
+ *
+ * Description:
+ */
+static int toi_swap_print_debug_stats(char *buffer, int size)
+{
+	int len = 0;
+
+	len = scnprintf(buffer, size, "- Swap Allocator enabled.\n");
+	if (swapfilename[0])
+		len += scnprintf(buffer+len, size-len,
+			"  Attempting to automatically swapon: %s.\n",
+			swapfilename);
+
+	si_swapinfo_no_compcache();
+
+	len += scnprintf(buffer+len, size-len,
+			"  Swap available for image: %lu pages.\n",
+			swapinfo.freeswap + swap_allocated);
+
+	return len;
+}
+
+static int header_locations_read_sysfs(const char *page, int count)
+{
+	int i, printedpartitionsmessage = 0, len = 0, haveswap = 0;
+	struct inode *swapf = NULL;
+	int zone;
+	char *path_page = (char *) toi_get_free_page(10, GFP_KERNEL);
+	char *path, *output = (char *) page;
+	int path_len;
+
+	if (!page)
+		return 0;
+
+	for (i = 0; i < MAX_SWAPFILES; i++) {
+		struct swap_info_struct *si =  get_swap_info_struct(i);
+
+		if (!si || !(si->flags & SWP_WRITEOK))
+			continue;
+
+		if (S_ISBLK(si->swap_file->f_mapping->host->i_mode)) {
+			haveswap = 1;
+			if (!printedpartitionsmessage) {
+				len += sprintf(output + len,
+					"For swap partitions, simply use the "
+					"format: resume=swap:/dev/hda1.\n");
+				printedpartitionsmessage = 1;
+			}
+		} else {
+			path_len = 0;
+
+			path = d_path(&si->swap_file->f_path, path_page,
+					PAGE_SIZE);
+			path_len = snprintf(path_page, PAGE_SIZE, "%s", path);
+
+			haveswap = 1;
+			swapf = si->swap_file->f_mapping->host;
+			zone = bmap(swapf, 0);
+			if (!zone) {
+				len += sprintf(output + len,
+					"Swapfile %s has been corrupted. Reuse"
+					" mkswap on it and try again.\n",
+					path_page);
+			} else {
+				char name_buffer[BDEVNAME_SIZE];
+				len += sprintf(output + len,
+					"For swapfile `%s`,"
+					" use resume=swap:/dev/%s:0x%x.\n",
+					path_page,
+					bdevname(si->bdev, name_buffer),
+					zone << (swapf->i_blkbits - 9));
+			}
+		}
+	}
+
+	if (!haveswap)
+		len = sprintf(output, "You need to turn on swap partitions "
+				"before examining this file.\n");
+
+	toi_free_page(10, (unsigned long) path_page);
+	return len;
+}
+
+static struct toi_sysfs_data sysfs_params[] = {
+	SYSFS_STRING("swapfilename", SYSFS_RW, swapfilename, 255, 0, NULL),
+	SYSFS_CUSTOM("headerlocations", SYSFS_READONLY,
+			header_locations_read_sysfs, NULL, 0, NULL),
+	SYSFS_INT("enabled", SYSFS_RW, &toi_swapops.enabled, 0, 1, 0,
+			attempt_to_parse_resume_device2),
+};
+
+static struct toi_bio_allocator_ops toi_bio_swapops = {
+	.register_storage			= toi_swap_register_storage,
+	.storage_available			= toi_swap_storage_available,
+	.allocate_storage			= toi_swap_allocate_storage,
+	.bmap					= get_main_pool_phys_params,
+	.free_storage				= toi_swap_free_storage,
+        .free_unused_storage                    = toi_swap_free_unused_storage,
+};
+
+static struct toi_module_ops toi_swapops = {
+	.type					= BIO_ALLOCATOR_MODULE,
+	.name					= "swap storage",
+	.directory				= "swap",
+	.module					= THIS_MODULE,
+	.memory_needed				= toi_swap_memory_needed,
+	.print_debug_info			= toi_swap_print_debug_stats,
+	.initialise				= toi_swap_initialise,
+	.cleanup				= toi_swap_cleanup,
+	.bio_allocator_ops			= &toi_bio_swapops,
+
+	.sysfs_data		= sysfs_params,
+	.num_sysfs_entries	= sizeof(sysfs_params) /
+		sizeof(struct toi_sysfs_data),
+};
+
+/* ---- Registration ---- */
+static __init int toi_swap_load(void)
+{
+	return toi_register_module(&toi_swapops);
+}
+
+late_initcall(toi_swap_load);