1 files changed, 403 insertions, 0 deletions
diff --git a/kernel/power/tuxonice_bio_signature.c b/kernel/power/tuxonice_bio_signature.c
new file mode 100644
index 000000000..ead874f8e
--- /dev/null
+++ b/kernel/power/tuxonice_bio_signature.c
@@ -0,0 +1,403 @@
+/*
+ * kernel/power/tuxonice_bio_signature.c
+ *
+ * Copyright (C) 2004-2015 Nigel Cunningham (nigel at nigelcunningham com au)
+ *
+ * Distributed under GPLv2.
+ *
+ */
+
+#include <linux/fs_uuid.h>
+
+#include "tuxonice.h"
+#include "tuxonice_sysfs.h"
+#include "tuxonice_modules.h"
+#include "tuxonice_prepare_image.h"
+#include "tuxonice_bio.h"
+#include "tuxonice_ui.h"
+#include "tuxonice_alloc.h"
+#include "tuxonice_io.h"
+#include "tuxonice_builtin.h"
+#include "tuxonice_bio_internal.h"
+
+struct sig_data *toi_sig_data;
+
+/* Struct of swap header pages */
+
+struct old_sig_data {
+	dev_t device;
+	unsigned long sector;
+	int resume_attempted;
+	int orig_sig_type;
+};
+
+union diskpage {
+	union swap_header swh;	/* swh.magic is the only member used */
+	struct sig_data sig_data;
+	struct old_sig_data old_sig_data;
+};
+
+union p_diskpage {
+	union diskpage *pointer;
+	char *ptr;
+	unsigned long address;
+};
+
+char *toi_cur_sig_page;
+char *toi_orig_sig_page;
+int have_image;
+int have_old_image;
+
+int get_signature_page(void)
+{
+	if (!toi_cur_sig_page) {
+		toi_message(TOI_IO, TOI_VERBOSE, 0,
+				"Allocating current signature page.");
+		toi_cur_sig_page = (char *) toi_get_zeroed_page(38,
+			TOI_ATOMIC_GFP);
+		if (!toi_cur_sig_page) {
+			printk(KERN_ERR "Failed to allocate memory for the "
+				"current image signature.\n");
+			return -ENOMEM;
+		}
+
+		toi_sig_data = (struct sig_data *) toi_cur_sig_page;
+	}
+
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "Reading signature from dev %lx,"
+			" sector %d.",
+			resume_block_device->bd_dev, resume_firstblock);
+
+	return toi_bio_ops.bdev_page_io(READ, resume_block_device,
+		resume_firstblock, virt_to_page(toi_cur_sig_page));
+}
+
+void forget_signature_page(void)
+{
+	if (toi_cur_sig_page) {
+		toi_sig_data = NULL;
+		toi_message(TOI_IO, TOI_VERBOSE, 0, "Freeing toi_cur_sig_page"
+				" (%p).", toi_cur_sig_page);
+		toi_free_page(38, (unsigned long) toi_cur_sig_page);
+		toi_cur_sig_page = NULL;
+	}
+
+	if (toi_orig_sig_page) {
+		toi_message(TOI_IO, TOI_VERBOSE, 0, "Freeing toi_orig_sig_page"
+				" (%p).", toi_orig_sig_page);
+		toi_free_page(38, (unsigned long) toi_orig_sig_page);
+		toi_orig_sig_page = NULL;
+	}
+}
+
+/*
+ * We need to ensure we use the signature page that's currently on disk,
+ * so as to not remove the image header. Post-atomic-restore, the orig sig
+ * page will be empty, so we can use that as our method of knowing that we
+ * need to load the on-disk signature and not use the non-image sig in
+ * memory. (We're going to powerdown after writing the change, so it's safe.
+ */
+int toi_bio_mark_resume_attempted(int flag)
+{
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "Make resume attempted = %d.",
+			flag);
+	if (!toi_orig_sig_page) {
+		forget_signature_page();
+		get_signature_page();
+	}
+	toi_sig_data->resumed_before = flag;
+	return toi_bio_ops.bdev_page_io(WRITE, resume_block_device,
+		resume_firstblock, virt_to_page(toi_cur_sig_page));
+}
+
+int toi_bio_mark_have_image(void)
+{
+	int result = 0;
+	char buf[32];
+	struct fs_info *fs_info;
+
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "Recording that an image exists.");
+	memcpy(toi_sig_data->sig, tuxonice_signature,
+			sizeof(tuxonice_signature));
+	toi_sig_data->have_image = 1;
+	toi_sig_data->resumed_before = 0;
+	toi_sig_data->header_dev_t = get_header_dev_t();
+	toi_sig_data->have_uuid = 0;
+
+	fs_info = fs_info_from_block_dev(get_header_bdev());
+	if (fs_info && !IS_ERR(fs_info)) {
+		memcpy(toi_sig_data->header_uuid, &fs_info->uuid, 16);
+		free_fs_info(fs_info);
+	} else
+		result = (int) PTR_ERR(fs_info);
+
+	if (!result) {
+		toi_message(TOI_IO, TOI_VERBOSE, 0, "Got uuid for dev_t %s.",
+				format_dev_t(buf, get_header_dev_t()));
+		toi_sig_data->have_uuid = 1;
+	} else
+		toi_message(TOI_IO, TOI_VERBOSE, 0, "Could not get uuid for "
+				"dev_t %s.",
+				format_dev_t(buf, get_header_dev_t()));
+
+	toi_sig_data->first_header_block = get_headerblock();
+	have_image = 1;
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "header dev_t is %x. First block "
+			"is %d.", toi_sig_data->header_dev_t,
+			toi_sig_data->first_header_block);
+
+	memcpy(toi_sig_data->sig2, tuxonice_signature,
+			sizeof(tuxonice_signature));
+	toi_sig_data->header_version = TOI_HEADER_VERSION;
+
+	return toi_bio_ops.bdev_page_io(WRITE, resume_block_device,
+		resume_firstblock, virt_to_page(toi_cur_sig_page));
+}
+
+int remove_old_signature(void)
+{
+	union p_diskpage swap_header_page = (union p_diskpage) toi_cur_sig_page;
+	char *orig_sig;
+	char *header_start = (char *) toi_get_zeroed_page(38, TOI_ATOMIC_GFP);
+	int result;
+	struct block_device *header_bdev;
+	struct old_sig_data *old_sig_data =
+		&swap_header_page.pointer->old_sig_data;
+
+	header_bdev = toi_open_bdev(NULL, old_sig_data->device, 1);
+	result = toi_bio_ops.bdev_page_io(READ, header_bdev,
+			old_sig_data->sector, virt_to_page(header_start));
+
+	if (result)
+		goto out;
+
+	/*
+	 * TODO: Get the original contents of the first bytes of the swap
+	 * header page.
+	 */
+	if (!old_sig_data->orig_sig_type)
+		orig_sig = "SWAP-SPACE";
+	else
+		orig_sig = "SWAPSPACE2";
+
+	memcpy(swap_header_page.pointer->swh.magic.magic, orig_sig, 10);
+	memcpy(swap_header_page.ptr, header_start, 10);
+
+	result = toi_bio_ops.bdev_page_io(WRITE, resume_block_device,
+		resume_firstblock, virt_to_page(swap_header_page.ptr));
+
+out:
+	toi_close_bdev(header_bdev);
+	have_old_image = 0;
+	toi_free_page(38, (unsigned long) header_start);
+	return result;
+}
+
+/*
+ * toi_bio_restore_original_signature - restore the original signature
+ *
+ * At boot time (aborting pre atomic-restore), toi_orig_sig_page gets used.
+ * It will have the original signature page contents, stored in the image
+ * header. Post atomic-restore, we use :toi_cur_sig_page, which will contain
+ * the contents that were loaded when we started the cycle.
+ */
+int toi_bio_restore_original_signature(void)
+{
+	char *use = toi_orig_sig_page ? toi_orig_sig_page : toi_cur_sig_page;
+
+	if (have_old_image)
+		return remove_old_signature();
+
+	if (!use) {
+		printk("toi_bio_restore_original_signature: No signature "
+				"page loaded.\n");
+		return 0;
+	}
+
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "Recording that no image exists.");
+	have_image = 0;
+	toi_sig_data->have_image = 0;
+	return toi_bio_ops.bdev_page_io(WRITE, resume_block_device,
+		resume_firstblock, virt_to_page(use));
+}
+
+/*
+ * check_for_signature - See whether we have an image.
+ *
+ * Returns 0 if no image, 1 if there is one, -1 if indeterminate.
+ */
+int toi_check_for_signature(void)
+{
+	union p_diskpage swap_header_page;
+	int type;
+	const char *normal_sigs[] = {"SWAP-SPACE", "SWAPSPACE2" };
+	const char *swsusp_sigs[] = {"S1SUSP", "S2SUSP", "S1SUSPEND" };
+	char *swap_header;
+
+	if (!toi_cur_sig_page) {
+		int result = get_signature_page();
+
+		if (result)
+			return result;
+	}
+
+	/*
+	 * Start by looking for the binary header.
+	 */
+	if (!memcmp(tuxonice_signature, toi_cur_sig_page,
+				sizeof(tuxonice_signature))) {
+		have_image = toi_sig_data->have_image;
+		toi_message(TOI_IO, TOI_VERBOSE, 0, "Have binary signature. "
+				"Have image is %d.", have_image);
+		if (have_image)
+			toi_message(TOI_IO, TOI_VERBOSE, 0, "header dev_t is "
+					"%x. First block is %d.",
+					toi_sig_data->header_dev_t,
+					toi_sig_data->first_header_block);
+		return toi_sig_data->have_image;
+	}
+
+	/*
+	 * Failing that, try old file allocator headers.
+	 */
+
+	if (!memcmp(HaveImage, toi_cur_sig_page, strlen(HaveImage))) {
+		have_image = 1;
+		return 1;
+	}
+
+	have_image = 0;
+
+	if (!memcmp(NoImage, toi_cur_sig_page, strlen(NoImage)))
+		return 0;
+
+	/*
+	 * Nope? How about swap?
+	 */
+	swap_header_page = (union p_diskpage) toi_cur_sig_page;
+	swap_header = swap_header_page.pointer->swh.magic.magic;
+
+	/* Normal swapspace? */
+	for (type = 0; type < 2; type++)
+		if (!memcmp(normal_sigs[type], swap_header,
+					strlen(normal_sigs[type])))
+			return 0;
+
+	/* Swsusp or uswsusp? */
+	for (type = 0; type < 3; type++)
+		if (!memcmp(swsusp_sigs[type], swap_header,
+					strlen(swsusp_sigs[type])))
+			return 2;
+
+	/* Old TuxOnIce version? */
+	if (!memcmp(tuxonice_signature, swap_header,
+				sizeof(tuxonice_signature) - 1)) {
+		toi_message(TOI_IO, TOI_VERBOSE, 0, "Found old TuxOnIce "
+				"signature.");
+		have_old_image = 1;
+		return 3;
+	}
+
+	return -1;
+}
+
+/*
+ * Image_exists
+ *
+ * Returns -1 if don't know, otherwise 0 (no) or 1 (yes).
+ */
+int toi_bio_image_exists(int quiet)
+{
+	int result;
+	char *msg = NULL;
+
+	toi_message(TOI_IO, TOI_VERBOSE, 0, "toi_bio_image_exists.");
+
+	if (!resume_dev_t) {
+		if (!quiet)
+			printk(KERN_INFO "Not even trying to read header "
+				"because resume_dev_t is not set.\n");
+		return -1;
+	}
+
+	if (open_resume_dev_t(0, quiet))
+		return -1;
+
+	result = toi_check_for_signature();
+
+	clear_toi_state(TOI_RESUMED_BEFORE);
+	if (toi_sig_data->resumed_before)
+		set_toi_state(TOI_RESUMED_BEFORE);
+
+	if (quiet || result == -ENOMEM)
+		return result;
+
+	if (result == -1)
+		msg = "TuxOnIce: Unable to find a signature."
+				" Could you have moved a swap file?\n";
+	else if (!result)
+		msg = "TuxOnIce: No image found.\n";
+	else if (result == 1)
+		msg = "TuxOnIce: Image found.\n";
+	else if (result == 2)
+		msg = "TuxOnIce: uswsusp or swsusp image found.\n";
+	else if (result == 3)
+		msg = "TuxOnIce: Old implementation's signature found.\n";
+
+	printk(KERN_INFO "%s", msg);
+
+	return result;
+}
+
+int toi_bio_scan_for_image(int quiet)
+{
+	struct block_device *bdev;
+	char default_name[255] = "";
+
+	if (!quiet)
+		printk(KERN_DEBUG "Scanning swap devices for TuxOnIce "
+				"signature...\n");
+	for (bdev = next_bdev_of_type(NULL, "swap"); bdev;
+				bdev = next_bdev_of_type(bdev, "swap")) {
+		int result;
+		char name[255] = "";
+		sprintf(name, "%u:%u", MAJOR(bdev->bd_dev),
+				MINOR(bdev->bd_dev));
+		if (!quiet)
+			printk(KERN_DEBUG "- Trying %s.\n", name);
+		resume_block_device = bdev;
+		resume_dev_t = bdev->bd_dev;
+
+		result = toi_check_for_signature();
+
+		resume_block_device = NULL;
+		resume_dev_t = MKDEV(0, 0);
+
+		if (!default_name[0])
+			strcpy(default_name, name);
+
+		if (result == 1) {
+			/* Got one! */
+			strcpy(resume_file, name);
+			next_bdev_of_type(bdev, NULL);
+			if (!quiet)
+				printk(KERN_DEBUG " ==> Image found on %s.\n",
+						resume_file);
+			return 1;
+		}
+		forget_signature_page();
+	}
+
+	if (!quiet)
+		printk(KERN_DEBUG "TuxOnIce scan: No image found.\n");
+	strcpy(resume_file, default_name);
+	return 0;
+}
+
+int toi_bio_get_header_version(void)
+{
+	return (memcmp(toi_sig_data->sig2, tuxonice_signature,
+				sizeof(tuxonice_signature))) ?
+		0 : toi_sig_data->header_version;
+
+}