* Fixed runaway init
*
* Rafael J. Wysocki <rjw@sisk.pl>
- * Reworked the freeing of memory and the handling of swap
+ * Added the swap map data structure and reworked the handling of swap
*
* More state savers are welcome. Especially for the scsi layer...
*
* For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
*/
+#include <linux/module.h>
#include <linux/mm.h>
#include <linux/suspend.h>
+#include <linux/smp_lock.h>
+#include <linux/file.h>
+#include <linux/utsname.h>
+#include <linux/version.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
#include <linux/spinlock.h>
+#include <linux/genhd.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/swap.h>
#include <linux/pm.h>
+#include <linux/device.h>
+#include <linux/buffer_head.h>
#include <linux/swapops.h>
#include <linux/bootmem.h>
#include <linux/syscalls.h>
#include <linux/highmem.h>
+#include <linux/bio.h>
+
+#include <asm/uaccess.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+#include <asm/io.h>
#include "power.h"
*/
unsigned long image_size = 500 * 1024 * 1024;
-int in_suspend __nosavedata = 0;
-
#ifdef CONFIG_HIGHMEM
unsigned int count_highmem_pages(void);
int save_highmem(void);
int restore_highmem(void);
#else
-static inline int save_highmem(void) { return 0; }
-static inline int restore_highmem(void) { return 0; }
-static inline unsigned int count_highmem_pages(void) { return 0; }
+static int save_highmem(void) { return 0; }
+static int restore_highmem(void) { return 0; }
+static unsigned int count_highmem_pages(void) { return 0; }
#endif
+extern char resume_file[];
+
+#define SWSUSP_SIG "S1SUSPEND"
+
+static struct swsusp_header {
+ char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)];
+ swp_entry_t image;
+ char orig_sig[10];
+ char sig[10];
+} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
+
+static struct swsusp_info swsusp_info;
+
+/*
+ * Saving part...
+ */
+
+static unsigned short root_swap = 0xffff;
+
+static int mark_swapfiles(swp_entry_t start)
+{
+ int error;
+
+ rw_swap_page_sync(READ,
+ swp_entry(root_swap, 0),
+ virt_to_page((unsigned long)&swsusp_header));
+ if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
+ !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
+ memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
+ memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
+ swsusp_header.image = start;
+ error = rw_swap_page_sync(WRITE,
+ swp_entry(root_swap, 0),
+ virt_to_page((unsigned long)
+ &swsusp_header));
+ } else {
+ pr_debug("swsusp: Partition is not swap space.\n");
+ error = -ENODEV;
+ }
+ return error;
+}
+
+/*
+ * Check whether the swap device is the specified resume
+ * device, irrespective of whether they are specified by
+ * identical names.
+ *
+ * (Thus, device inode aliasing is allowed. You can say /dev/hda4
+ * instead of /dev/ide/host0/bus0/target0/lun0/part4 [if using devfs]
+ * and they'll be considered the same device. This is *necessary* for
+ * devfs, since the resume code can only recognize the form /dev/hda4,
+ * but the suspend code would see the long name.)
+ */
+static inline int is_resume_device(const struct swap_info_struct *swap_info)
+{
+ struct file *file = swap_info->swap_file;
+ struct inode *inode = file->f_dentry->d_inode;
+
+ return S_ISBLK(inode->i_mode) &&
+ swsusp_resume_device == MKDEV(imajor(inode), iminor(inode));
+}
+
+static int swsusp_swap_check(void) /* This is called before saving image */
+{
+ int i;
+
+ spin_lock(&swap_lock);
+ for (i = 0; i < MAX_SWAPFILES; i++) {
+ if (!(swap_info[i].flags & SWP_WRITEOK))
+ continue;
+ if (!swsusp_resume_device || is_resume_device(swap_info + i)) {
+ spin_unlock(&swap_lock);
+ root_swap = i;
+ return 0;
+ }
+ }
+ spin_unlock(&swap_lock);
+ return -ENODEV;
+}
+
/**
- * The following functions are used for tracing the allocated
- * swap pages, so that they can be freed in case of an error.
+ * write_page - Write one page to a fresh swap location.
+ * @addr: Address we're writing.
+ * @loc: Place to store the entry we used.
*
- * The functions operate on a linked bitmap structure defined
- * in power.h
+ * Allocate a new swap entry and 'sync' it. Note we discard -EIO
+ * errors. That is an artifact left over from swsusp. It did not
+ * check the return of rw_swap_page_sync() at all, since most pages
+ * written back to swap would return -EIO.
+ * This is a partial improvement, since we will at least return other
+ * errors, though we need to eventually fix the damn code.
*/
+static int write_page(unsigned long addr, swp_entry_t *loc)
+{
+ swp_entry_t entry;
+ int error = -ENOSPC;
-void free_bitmap(struct bitmap_page *bitmap)
+ entry = get_swap_page_of_type(root_swap);
+ if (swp_offset(entry)) {
+ error = rw_swap_page_sync(WRITE, entry, virt_to_page(addr));
+ if (!error || error == -EIO)
+ *loc = entry;
+ }
+ return error;
+}
+
+/**
+ * Swap map-handling functions
+ *
+ * The swap map is a data structure used for keeping track of each page
+ * written to the swap. It consists of many swap_map_page structures
+ * that contain each an array of MAP_PAGE_SIZE swap entries.
+ * These structures are linked together with the help of either the
+ * .next (in memory) or the .next_swap (in swap) member.
+ *
+ * The swap map is created during suspend. At that time we need to keep
+ * it in memory, because we have to free all of the allocated swap
+ * entries if an error occurs. The memory needed is preallocated
+ * so that we know in advance if there's enough of it.
+ *
+ * The first swap_map_page structure is filled with the swap entries that
+ * correspond to the first MAP_PAGE_SIZE data pages written to swap and
+ * so on. After the all of the data pages have been written, the order
+ * of the swap_map_page structures in the map is reversed so that they
+ * can be read from swap in the original order. This causes the data
+ * pages to be loaded in exactly the same order in which they have been
+ * saved.
+ *
+ * During resume we only need to use one swap_map_page structure
+ * at a time, which means that we only need to use two memory pages for
+ * reading the image - one for reading the swap_map_page structures
+ * and the second for reading the data pages from swap.
+ */
+
+#define MAP_PAGE_SIZE ((PAGE_SIZE - sizeof(swp_entry_t) - sizeof(void *)) \
+ / sizeof(swp_entry_t))
+
+struct swap_map_page {
+ swp_entry_t entries[MAP_PAGE_SIZE];
+ swp_entry_t next_swap;
+ struct swap_map_page *next;
+};
+
+static inline void free_swap_map(struct swap_map_page *swap_map)
{
- struct bitmap_page *bp;
+ struct swap_map_page *swp;
- while (bitmap) {
- bp = bitmap->next;
- free_page((unsigned long)bitmap);
- bitmap = bp;
+ while (swap_map) {
+ swp = swap_map->next;
+ free_page((unsigned long)swap_map);
+ swap_map = swp;
}
}
-struct bitmap_page *alloc_bitmap(unsigned int nr_bits)
+static struct swap_map_page *alloc_swap_map(unsigned int nr_pages)
{
- struct bitmap_page *bitmap, *bp;
- unsigned int n;
+ struct swap_map_page *swap_map, *swp;
+ unsigned n = 0;
- if (!nr_bits)
+ if (!nr_pages)
return NULL;
- bitmap = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL);
- bp = bitmap;
- for (n = BITMAP_PAGE_BITS; n < nr_bits; n += BITMAP_PAGE_BITS) {
- bp->next = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL);
- bp = bp->next;
- if (!bp) {
- free_bitmap(bitmap);
+ pr_debug("alloc_swap_map(): nr_pages = %d\n", nr_pages);
+ swap_map = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
+ swp = swap_map;
+ for (n = MAP_PAGE_SIZE; n < nr_pages; n += MAP_PAGE_SIZE) {
+ swp->next = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
+ swp = swp->next;
+ if (!swp) {
+ free_swap_map(swap_map);
return NULL;
}
}
- return bitmap;
+ return swap_map;
}
-static int bitmap_set(struct bitmap_page *bitmap, unsigned long bit)
+/**
+ * reverse_swap_map - reverse the order of pages in the swap map
+ * @swap_map
+ */
+
+static inline struct swap_map_page *reverse_swap_map(struct swap_map_page *swap_map)
{
- unsigned int n;
+ struct swap_map_page *prev, *next;
- n = BITMAP_PAGE_BITS;
- while (bitmap && n <= bit) {
- n += BITMAP_PAGE_BITS;
- bitmap = bitmap->next;
+ prev = NULL;
+ while (swap_map) {
+ next = swap_map->next;
+ swap_map->next = prev;
+ prev = swap_map;
+ swap_map = next;
}
- if (!bitmap)
- return -EINVAL;
- n -= BITMAP_PAGE_BITS;
- bit -= n;
- n = 0;
- while (bit >= BITS_PER_CHUNK) {
- bit -= BITS_PER_CHUNK;
- n++;
+ return prev;
+}
+
+/**
+ * free_swap_map_entries - free the swap entries allocated to store
+ * the swap map @swap_map (this is only called in case of an error)
+ */
+static inline void free_swap_map_entries(struct swap_map_page *swap_map)
+{
+ while (swap_map) {
+ if (swap_map->next_swap.val)
+ swap_free(swap_map->next_swap);
+ swap_map = swap_map->next;
}
- bitmap->chunks[n] |= (1UL << bit);
+}
+
+/**
+ * save_swap_map - save the swap map used for tracing the data pages
+ * stored in the swap
+ */
+
+static int save_swap_map(struct swap_map_page *swap_map, swp_entry_t *start)
+{
+ swp_entry_t entry = (swp_entry_t){0};
+ int error;
+
+ while (swap_map) {
+ swap_map->next_swap = entry;
+ if ((error = write_page((unsigned long)swap_map, &entry)))
+ return error;
+ swap_map = swap_map->next;
+ }
+ *start = entry;
return 0;
}
-unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap)
+/**
+ * free_image_entries - free the swap entries allocated to store
+ * the image data pages (this is only called in case of an error)
+ */
+
+static inline void free_image_entries(struct swap_map_page *swp)
{
- unsigned long offset;
+ unsigned k;
- offset = swp_offset(get_swap_page_of_type(swap));
- if (offset) {
- if (bitmap_set(bitmap, offset)) {
- swap_free(swp_entry(swap, offset));
- offset = 0;
- }
+ while (swp) {
+ for (k = 0; k < MAP_PAGE_SIZE; k++)
+ if (swp->entries[k].val)
+ swap_free(swp->entries[k]);
+ swp = swp->next;
}
- return offset;
}
-void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
+/**
+ * The swap_map_handle structure is used for handling the swap map in
+ * a file-alike way
+ */
+
+struct swap_map_handle {
+ struct swap_map_page *cur;
+ unsigned int k;
+};
+
+static inline void init_swap_map_handle(struct swap_map_handle *handle,
+ struct swap_map_page *map)
+{
+ handle->cur = map;
+ handle->k = 0;
+}
+
+static inline int swap_map_write_page(struct swap_map_handle *handle,
+ unsigned long addr)
+{
+ int error;
+
+ error = write_page(addr, handle->cur->entries + handle->k);
+ if (error)
+ return error;
+ if (++handle->k >= MAP_PAGE_SIZE) {
+ handle->cur = handle->cur->next;
+ handle->k = 0;
+ }
+ return 0;
+}
+
+/**
+ * save_image_data - save the data pages pointed to by the PBEs
+ * from the list @pblist using the swap map handle @handle
+ * (assume there are @nr_pages data pages to save)
+ */
+
+static int save_image_data(struct pbe *pblist,
+ struct swap_map_handle *handle,
+ unsigned int nr_pages)
+{
+ unsigned int m;
+ struct pbe *p;
+ int error = 0;
+
+ printk("Saving image data pages (%u pages) ... ", nr_pages);
+ m = nr_pages / 100;
+ if (!m)
+ m = 1;
+ nr_pages = 0;
+ for_each_pbe (p, pblist) {
+ error = swap_map_write_page(handle, p->address);
+ if (error)
+ break;
+ if (!(nr_pages % m))
+ printk("\b\b\b\b%3d%%", nr_pages / m);
+ nr_pages++;
+ }
+ if (!error)
+ printk("\b\b\b\bdone\n");
+ return error;
+}
+
+static void dump_info(void)
+{
+ pr_debug(" swsusp: Version: %u\n",swsusp_info.version_code);
+ pr_debug(" swsusp: Num Pages: %ld\n",swsusp_info.num_physpages);
+ pr_debug(" swsusp: UTS Sys: %s\n",swsusp_info.uts.sysname);
+ pr_debug(" swsusp: UTS Node: %s\n",swsusp_info.uts.nodename);
+ pr_debug(" swsusp: UTS Release: %s\n",swsusp_info.uts.release);
+ pr_debug(" swsusp: UTS Version: %s\n",swsusp_info.uts.version);
+ pr_debug(" swsusp: UTS Machine: %s\n",swsusp_info.uts.machine);
+ pr_debug(" swsusp: UTS Domain: %s\n",swsusp_info.uts.domainname);
+ pr_debug(" swsusp: CPUs: %d\n",swsusp_info.cpus);
+ pr_debug(" swsusp: Image: %ld Pages\n",swsusp_info.image_pages);
+ pr_debug(" swsusp: Total: %ld Pages\n", swsusp_info.pages);
+}
+
+static void init_header(unsigned int nr_pages)
+{
+ memset(&swsusp_info, 0, sizeof(swsusp_info));
+ swsusp_info.version_code = LINUX_VERSION_CODE;
+ swsusp_info.num_physpages = num_physpages;
+ memcpy(&swsusp_info.uts, &system_utsname, sizeof(system_utsname));
+
+ swsusp_info.cpus = num_online_cpus();
+ swsusp_info.image_pages = nr_pages;
+ swsusp_info.pages = nr_pages +
+ ((nr_pages * sizeof(long) + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
+}
+
+/**
+ * pack_orig_addresses - the .orig_address fields of the PBEs from the
+ * list starting at @pbe are stored in the array @buf[] (1 page)
+ */
+
+static inline struct pbe *pack_orig_addresses(unsigned long *buf,
+ struct pbe *pbe)
+{
+ int j;
+
+ for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
+ buf[j] = pbe->orig_address;
+ pbe = pbe->next;
+ }
+ if (!pbe)
+ for (; j < PAGE_SIZE / sizeof(long); j++)
+ buf[j] = 0;
+ return pbe;
+}
+
+/**
+ * save_image_metadata - save the .orig_address fields of the PBEs
+ * from the list @pblist using the swap map handle @handle
+ */
+
+static int save_image_metadata(struct pbe *pblist,
+ struct swap_map_handle *handle)
{
- unsigned int bit, n;
- unsigned long test;
+ unsigned long *buf;
+ unsigned int n = 0;
+ struct pbe *p;
+ int error = 0;
- bit = 0;
- while (bitmap) {
- for (n = 0; n < BITMAP_PAGE_CHUNKS; n++)
- for (test = 1UL; test; test <<= 1) {
- if (bitmap->chunks[n] & test)
- swap_free(swp_entry(swap, bit));
- bit++;
- }
- bitmap = bitmap->next;
+ printk("Saving image metadata ... ");
+ buf = (unsigned long *)get_zeroed_page(GFP_ATOMIC);
+ if (!buf)
+ return -ENOMEM;
+ p = pblist;
+ while (p) {
+ p = pack_orig_addresses(buf, p);
+ error = swap_map_write_page(handle, (unsigned long)buf);
+ if (error)
+ break;
+ n++;
}
+ free_page((unsigned long)buf);
+ if (!error)
+ printk("done (%u pages saved)\n", n);
+ return error;
+}
+
+/**
+ * enough_swap - Make sure we have enough swap to save the image.
+ *
+ * Returns TRUE or FALSE after checking the total amount of swap
+ * space avaiable from the resume partition.
+ */
+
+static int enough_swap(unsigned int nr_pages)
+{
+ unsigned int free_swap = swap_info[root_swap].pages -
+ swap_info[root_swap].inuse_pages;
+
+ pr_debug("swsusp: free swap pages: %u\n", free_swap);
+ return free_swap > (nr_pages + PAGES_FOR_IO +
+ (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
+}
+
+/**
+ * swsusp_write - Write entire image and metadata.
+ *
+ * It is important _NOT_ to umount filesystems at this point. We want
+ * them synced (in case something goes wrong) but we DO not want to mark
+ * filesystem clean: it is not. (And it does not matter, if we resume
+ * correctly, we'll mark system clean, anyway.)
+ */
+
+int swsusp_write(struct pbe *pblist, unsigned int nr_pages)
+{
+ struct swap_map_page *swap_map;
+ struct swap_map_handle handle;
+ swp_entry_t start;
+ int error;
+
+ if ((error = swsusp_swap_check())) {
+ printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n");
+ return error;
+ }
+ if (!enough_swap(nr_pages)) {
+ printk(KERN_ERR "swsusp: Not enough free swap\n");
+ return -ENOSPC;
+ }
+
+ init_header(nr_pages);
+ swap_map = alloc_swap_map(swsusp_info.pages);
+ if (!swap_map)
+ return -ENOMEM;
+ init_swap_map_handle(&handle, swap_map);
+
+ error = swap_map_write_page(&handle, (unsigned long)&swsusp_info);
+ if (!error)
+ error = save_image_metadata(pblist, &handle);
+ if (!error)
+ error = save_image_data(pblist, &handle, nr_pages);
+ if (error)
+ goto Free_image_entries;
+
+ swap_map = reverse_swap_map(swap_map);
+ error = save_swap_map(swap_map, &start);
+ if (error)
+ goto Free_map_entries;
+
+ dump_info();
+ printk( "S" );
+ error = mark_swapfiles(start);
+ printk( "|\n" );
+ if (error)
+ goto Free_map_entries;
+
+Free_swap_map:
+ free_swap_map(swap_map);
+ return error;
+
+Free_map_entries:
+ free_swap_map_entries(swap_map);
+Free_image_entries:
+ free_image_entries(swap_map);
+ goto Free_swap_map;
}
/**
*/
#define SHRINK_BITE 10000
-static inline unsigned long __shrink_memory(long tmp)
-{
- if (tmp > SHRINK_BITE)
- tmp = SHRINK_BITE;
- return shrink_all_memory(tmp);
-}
int swsusp_shrink_memory(void)
{
PAGES_FOR_IO;
tmp = size;
for_each_zone (zone)
- if (!is_highmem(zone) && populated_zone(zone)) {
+ if (!is_highmem(zone))
tmp -= zone->free_pages;
- tmp += zone->lowmem_reserve[ZONE_NORMAL];
- }
if (tmp > 0) {
- tmp = __shrink_memory(tmp);
+ tmp = shrink_all_memory(SHRINK_BITE);
if (!tmp)
return -ENOMEM;
pages += tmp;
} else if (size > image_size / PAGE_SIZE) {
- tmp = __shrink_memory(size - (image_size / PAGE_SIZE));
+ tmp = shrink_all_memory(SHRINK_BITE);
pages += tmp;
}
printk("\b%c", p[i++%4]);
local_irq_enable();
return error;
}
+
+/**
+ * mark_unsafe_pages - mark the pages that cannot be used for storing
+ * the image during resume, because they conflict with the pages that
+ * had been used before suspend
+ */
+
+static void mark_unsafe_pages(struct pbe *pblist)
+{
+ struct zone *zone;
+ unsigned long zone_pfn;
+ struct pbe *p;
+
+ if (!pblist) /* a sanity check */
+ return;
+
+ /* Clear page flags */
+ for_each_zone (zone) {
+ for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
+ if (pfn_valid(zone_pfn + zone->zone_start_pfn))
+ ClearPageNosaveFree(pfn_to_page(zone_pfn +
+ zone->zone_start_pfn));
+ }
+
+ /* Mark orig addresses */
+ for_each_pbe (p, pblist)
+ SetPageNosaveFree(virt_to_page(p->orig_address));
+
+}
+
+static void copy_page_backup_list(struct pbe *dst, struct pbe *src)
+{
+ /* We assume both lists contain the same number of elements */
+ while (src) {
+ dst->orig_address = src->orig_address;
+ dst = dst->next;
+ src = src->next;
+ }
+}
+
+/*
+ * Using bio to read from swap.
+ * This code requires a bit more work than just using buffer heads
+ * but, it is the recommended way for 2.5/2.6.
+ * The following are to signal the beginning and end of I/O. Bios
+ * finish asynchronously, while we want them to happen synchronously.
+ * A simple atomic_t, and a wait loop take care of this problem.
+ */
+
+static atomic_t io_done = ATOMIC_INIT(0);
+
+static int end_io(struct bio *bio, unsigned int num, int err)
+{
+ if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
+ panic("I/O error reading memory image");
+ atomic_set(&io_done, 0);
+ return 0;
+}
+
+static struct block_device *resume_bdev;
+
+/**
+ * submit - submit BIO request.
+ * @rw: READ or WRITE.
+ * @off physical offset of page.
+ * @page: page we're reading or writing.
+ *
+ * Straight from the textbook - allocate and initialize the bio.
+ * If we're writing, make sure the page is marked as dirty.
+ * Then submit it and wait.
+ */
+
+static int submit(int rw, pgoff_t page_off, void *page)
+{
+ int error = 0;
+ struct bio *bio;
+
+ bio = bio_alloc(GFP_ATOMIC, 1);
+ if (!bio)
+ return -ENOMEM;
+ bio->bi_sector = page_off * (PAGE_SIZE >> 9);
+ bio->bi_bdev = resume_bdev;
+ bio->bi_end_io = end_io;
+
+ if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) {
+ printk("swsusp: ERROR: adding page to bio at %ld\n",page_off);
+ error = -EFAULT;
+ goto Done;
+ }
+
+
+ atomic_set(&io_done, 1);
+ submit_bio(rw | (1 << BIO_RW_SYNC), bio);
+ while (atomic_read(&io_done))
+ yield();
+ if (rw == READ)
+ bio_set_pages_dirty(bio);
+ Done:
+ bio_put(bio);
+ return error;
+}
+
+static int bio_read_page(pgoff_t page_off, void *page)
+{
+ return submit(READ, page_off, page);
+}
+
+static int bio_write_page(pgoff_t page_off, void *page)
+{
+ return submit(WRITE, page_off, page);
+}
+
+/**
+ * The following functions allow us to read data using a swap map
+ * in a file-alike way
+ */
+
+static inline void release_swap_map_reader(struct swap_map_handle *handle)
+{
+ if (handle->cur)
+ free_page((unsigned long)handle->cur);
+ handle->cur = NULL;
+}
+
+static inline int get_swap_map_reader(struct swap_map_handle *handle,
+ swp_entry_t start)
+{
+ int error;
+
+ if (!swp_offset(start))
+ return -EINVAL;
+ handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
+ if (!handle->cur)
+ return -ENOMEM;
+ error = bio_read_page(swp_offset(start), handle->cur);
+ if (error) {
+ release_swap_map_reader(handle);
+ return error;
+ }
+ handle->k = 0;
+ return 0;
+}
+
+static inline int swap_map_read_page(struct swap_map_handle *handle, void *buf)
+{
+ unsigned long offset;
+ int error;
+
+ if (!handle->cur)
+ return -EINVAL;
+ offset = swp_offset(handle->cur->entries[handle->k]);
+ if (!offset)
+ return -EINVAL;
+ error = bio_read_page(offset, buf);
+ if (error)
+ return error;
+ if (++handle->k >= MAP_PAGE_SIZE) {
+ handle->k = 0;
+ offset = swp_offset(handle->cur->next_swap);
+ if (!offset)
+ release_swap_map_reader(handle);
+ else
+ error = bio_read_page(offset, handle->cur);
+ }
+ return error;
+}
+
+static int check_header(void)
+{
+ char *reason = NULL;
+
+ dump_info();
+ if (swsusp_info.version_code != LINUX_VERSION_CODE)
+ reason = "kernel version";
+ if (swsusp_info.num_physpages != num_physpages)
+ reason = "memory size";
+ if (strcmp(swsusp_info.uts.sysname,system_utsname.sysname))
+ reason = "system type";
+ if (strcmp(swsusp_info.uts.release,system_utsname.release))
+ reason = "kernel release";
+ if (strcmp(swsusp_info.uts.version,system_utsname.version))
+ reason = "version";
+ if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
+ reason = "machine";
+ if (reason) {
+ printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason);
+ return -EPERM;
+ }
+ return 0;
+}
+
+/**
+ * load_image_data - load the image data using the swap map handle
+ * @handle and store them using the page backup list @pblist
+ * (assume there are @nr_pages pages to load)
+ */
+
+static int load_image_data(struct pbe *pblist,
+ struct swap_map_handle *handle,
+ unsigned int nr_pages)
+{
+ int error;
+ unsigned int m;
+ struct pbe *p;
+
+ if (!pblist)
+ return -EINVAL;
+ printk("Loading image data pages (%u pages) ... ", nr_pages);
+ m = nr_pages / 100;
+ if (!m)
+ m = 1;
+ nr_pages = 0;
+ p = pblist;
+ while (p) {
+ error = swap_map_read_page(handle, (void *)p->address);
+ if (error)
+ break;
+ p = p->next;
+ if (!(nr_pages % m))
+ printk("\b\b\b\b%3d%%", nr_pages / m);
+ nr_pages++;
+ }
+ if (!error)
+ printk("\b\b\b\bdone\n");
+ return error;
+}
+
+/**
+ * unpack_orig_addresses - copy the elements of @buf[] (1 page) to
+ * the PBEs in the list starting at @pbe
+ */
+
+static inline struct pbe *unpack_orig_addresses(unsigned long *buf,
+ struct pbe *pbe)
+{
+ int j;
+
+ for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
+ pbe->orig_address = buf[j];
+ pbe = pbe->next;
+ }
+ return pbe;
+}
+
+/**
+ * load_image_metadata - load the image metadata using the swap map
+ * handle @handle and put them into the PBEs in the list @pblist
+ */
+
+static int load_image_metadata(struct pbe *pblist, struct swap_map_handle *handle)
+{
+ struct pbe *p;
+ unsigned long *buf;
+ unsigned int n = 0;
+ int error = 0;
+
+ printk("Loading image metadata ... ");
+ buf = (unsigned long *)get_zeroed_page(GFP_ATOMIC);
+ if (!buf)
+ return -ENOMEM;
+ p = pblist;
+ while (p) {
+ error = swap_map_read_page(handle, buf);
+ if (error)
+ break;
+ p = unpack_orig_addresses(buf, p);
+ n++;
+ }
+ free_page((unsigned long)buf);
+ if (!error)
+ printk("done (%u pages loaded)\n", n);
+ return error;
+}
+
+int swsusp_read(struct pbe **pblist_ptr)
+{
+ int error;
+ struct pbe *p, *pblist;
+ struct swap_map_handle handle;
+ unsigned int nr_pages;
+
+ if (IS_ERR(resume_bdev)) {
+ pr_debug("swsusp: block device not initialised\n");
+ return PTR_ERR(resume_bdev);
+ }
+
+ error = get_swap_map_reader(&handle, swsusp_header.image);
+ if (!error)
+ error = swap_map_read_page(&handle, &swsusp_info);
+ if (!error)
+ error = check_header();
+ if (error)
+ return error;
+ nr_pages = swsusp_info.image_pages;
+ p = alloc_pagedir(nr_pages, GFP_ATOMIC, 0);
+ if (!p)
+ return -ENOMEM;
+ error = load_image_metadata(p, &handle);
+ if (!error) {
+ mark_unsafe_pages(p);
+ pblist = alloc_pagedir(nr_pages, GFP_ATOMIC, 1);
+ if (pblist)
+ copy_page_backup_list(pblist, p);
+ free_pagedir(p);
+ if (!pblist)
+ error = -ENOMEM;
+
+ /* Allocate memory for the image and read the data from swap */
+ if (!error)
+ error = alloc_data_pages(pblist, GFP_ATOMIC, 1);
+ if (!error) {
+ release_eaten_pages();
+ error = load_image_data(pblist, &handle, nr_pages);
+ }
+ if (!error)
+ *pblist_ptr = pblist;
+ }
+ release_swap_map_reader(&handle);
+
+ blkdev_put(resume_bdev);
+
+ if (!error)
+ pr_debug("swsusp: Reading resume file was successful\n");
+ else
+ pr_debug("swsusp: Error %d resuming\n", error);
+ return error;
+}
+
+/**
+ * swsusp_check - Check for swsusp signature in the resume device
+ */
+
+int swsusp_check(void)
+{
+ int error;
+
+ resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
+ if (!IS_ERR(resume_bdev)) {
+ set_blocksize(resume_bdev, PAGE_SIZE);
+ memset(&swsusp_header, 0, sizeof(swsusp_header));
+ if ((error = bio_read_page(0, &swsusp_header)))
+ return error;
+ if (!memcmp(SWSUSP_SIG, swsusp_header.sig, 10)) {
+ memcpy(swsusp_header.sig, swsusp_header.orig_sig, 10);
+ /* Reset swap signature now */
+ error = bio_write_page(0, &swsusp_header);
+ } else {
+ return -EINVAL;
+ }
+ if (error)
+ blkdev_put(resume_bdev);
+ else
+ pr_debug("swsusp: Signature found, resuming\n");
+ } else {
+ error = PTR_ERR(resume_bdev);
+ }
+
+ if (error)
+ pr_debug("swsusp: Error %d check for resume file\n", error);
+
+ return error;
+}
+
+/**
+ * swsusp_close - close swap device.
+ */
+
+void swsusp_close(void)
+{
+ if (IS_ERR(resume_bdev)) {
+ pr_debug("swsusp: block device not initialised\n");
+ return;
+ }
+
+ blkdev_put(resume_bdev);
+}
git://git.onelab.eu / linux-2.6.git / blobdiff