1 files changed, 526 insertions, 494 deletions

diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index c05f46e7348f..55a18d26abed 100644
--- a/kernel/power/swsusp.c
+++ b/kernel/power/swsusp.c
@@ -30,8 +30,8 @@
  * Alex Badea <vampire@go.ro>:
  * Fixed runaway init
  *
- * Andreas Steinmetz <ast@domdv.de>:
- * Added encrypted suspend option
+ * Rafael J. Wysocki <rjw@sisk.pl>
+ * Added the swap map data structure and reworked the handling of swap
  *
  * More state savers are welcome. Especially for the scsi layer...
  *
@@ -67,44 +67,33 @@
 #include <asm/tlbflush.h>
 #include <asm/io.h>
 
-#include <linux/random.h>
-#include <linux/crypto.h>
-#include <asm/scatterlist.h>
-
 #include "power.h"
 
+/*
+ * Preferred image size in MB (tunable via /sys/power/image_size).
+ * When it is set to N, swsusp will do its best to ensure the image
+ * size will not exceed N MB, but if that is impossible, it will
+ * try to create the smallest image possible.
+ */
+unsigned int image_size = 500;
+
 #ifdef CONFIG_HIGHMEM
+unsigned int count_highmem_pages(void);
 int save_highmem(void);
 int restore_highmem(void);
 #else
 static int save_highmem(void) { return 0; }
 static int restore_highmem(void) { return 0; }
+static unsigned int count_highmem_pages(void) { return 0; }
 #endif
 
-#define CIPHER "aes"
-#define MAXKEY 32
-#define MAXIV  32
-
 extern char resume_file[];
 
-/* Local variables that should not be affected by save */
-unsigned int nr_copy_pages __nosavedata = 0;
-
-/* Suspend pagedir is allocated before final copy, therefore it
-   must be freed after resume
-
-   Warning: this is even more evil than it seems. Pagedirs this file
-   talks about are completely different from page directories used by
-   MMU hardware.
- */
-suspend_pagedir_t *pagedir_nosave __nosavedata = NULL;
-
 #define SWSUSP_SIG      "S1SUSPEND"
 
 static struct swsusp_header {
-        char reserved[PAGE_SIZE - 20 - MAXKEY - MAXIV - sizeof(swp_entry_t)];
-        u8 key_iv[MAXKEY+MAXIV];
-        swp_entry_t swsusp_info;
+        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;
@@ -115,140 +104,9 @@ static struct swsusp_info swsusp_info;
  * Saving part...
  */
 
-/* We memorize in swapfile_used what swap devices are used for suspension */
-#define SWAPFILE_UNUSED    0
-#define SWAPFILE_SUSPEND   1    /* This is the suspending device */
-#define SWAPFILE_IGNORED   2    /* Those are other swap devices ignored for suspension */
-
-static unsigned short swapfile_used[MAX_SWAPFILES];
-static unsigned short root_swap;
-
-static int write_page(unsigned long addr, swp_entry_t *loc);
-static int bio_read_page(pgoff_t page_off, void *page);
-
-static u8 key_iv[MAXKEY+MAXIV];
-
-#ifdef CONFIG_SWSUSP_ENCRYPT
-
-static int crypto_init(int mode, void **mem)
-{
-        int error = 0;
-        int len;
-        char *modemsg;
-        struct crypto_tfm *tfm;
-
-        modemsg = mode ? "suspend not possible" : "resume not possible";
-
-        tfm = crypto_alloc_tfm(CIPHER, CRYPTO_TFM_MODE_CBC);
-        if(!tfm) {
-                printk(KERN_ERR "swsusp: no tfm, %s\n", modemsg);
-                error = -EINVAL;
-                goto out;
-        }
-
-        if(MAXKEY < crypto_tfm_alg_min_keysize(tfm)) {
-                printk(KERN_ERR "swsusp: key buffer too small, %s\n", modemsg);
-                error = -ENOKEY;
-                goto fail;
-        }
-
-        if (mode)
-                get_random_bytes(key_iv, MAXKEY+MAXIV);
-
-        len = crypto_tfm_alg_max_keysize(tfm);
-        if (len > MAXKEY)
-                len = MAXKEY;
-
-        if (crypto_cipher_setkey(tfm, key_iv, len)) {
-                printk(KERN_ERR "swsusp: key setup failure, %s\n", modemsg);
-                error = -EKEYREJECTED;
-                goto fail;
-        }
-
-        len = crypto_tfm_alg_ivsize(tfm);
-
-        if (MAXIV < len) {
-                printk(KERN_ERR "swsusp: iv buffer too small, %s\n", modemsg);
-                error = -EOVERFLOW;
-                goto fail;
-        }
-
-        crypto_cipher_set_iv(tfm, key_iv+MAXKEY, len);
-
-        *mem=(void *)tfm;
-
-        goto out;
-
-fail:   crypto_free_tfm(tfm);
-out:    return error;
-}
-
-static __inline__ void crypto_exit(void *mem)
-{
-        crypto_free_tfm((struct crypto_tfm *)mem);
-}
-
-static __inline__ int crypto_write(struct pbe *p, void *mem)
-{
-        int error = 0;
-        struct scatterlist src, dst;
-
-        src.page   = virt_to_page(p->address);
-        src.offset = 0;
-        src.length = PAGE_SIZE;
-        dst.page   = virt_to_page((void *)&swsusp_header);
-        dst.offset = 0;
-        dst.length = PAGE_SIZE;
-
-        error = crypto_cipher_encrypt((struct crypto_tfm *)mem, &dst, &src,
-                                        PAGE_SIZE);
-
-        if (!error)
-                error = write_page((unsigned long)&swsusp_header,
-                                &(p->swap_address));
-        return error;
-}
-
-static __inline__ int crypto_read(struct pbe *p, void *mem)
-{
-        int error = 0;
-        struct scatterlist src, dst;
-
-        error = bio_read_page(swp_offset(p->swap_address), (void *)p->address);
-        if (!error) {
-                src.offset = 0;
-                src.length = PAGE_SIZE;
-                dst.offset = 0;
-                dst.length = PAGE_SIZE;
-                src.page = dst.page = virt_to_page((void *)p->address);
-
-                error = crypto_cipher_decrypt((struct crypto_tfm *)mem, &dst,
-                                                &src, PAGE_SIZE);
-        }
-        return error;
-}
-#else
-static __inline__ int crypto_init(int mode, void *mem)
-{
-        return 0;
-}
-
-static __inline__ void crypto_exit(void *mem)
-{
-}
-
-static __inline__ int crypto_write(struct pbe *p, void *mem)
-{
-        return write_page(p->address, &(p->swap_address));
-}
+static unsigned short root_swap = 0xffff;
 
-static __inline__ int crypto_read(struct pbe *p, void *mem)
-{
-        return bio_read_page(swp_offset(p->swap_address), (void *)p->address);
-}
-#endif
-
-static int mark_swapfiles(swp_entry_t prev)
+static int mark_swapfiles(swp_entry_t start)
 {
         int error;
 
@@ -259,8 +117,7 @@ static int mark_swapfiles(swp_entry_t prev)
             !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
                 memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
                 memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
-                memcpy(swsusp_header.key_iv, key_iv, MAXKEY+MAXIV);
-                swsusp_header.swsusp_info = prev;
+                swsusp_header.image = start;
                 error = rw_swap_page_sync(WRITE,
                                           swp_entry(root_swap, 0),
                                           virt_to_page((unsigned long)
@@ -283,7 +140,7 @@ static int mark_swapfiles(swp_entry_t prev)
  * devfs, since the resume code can only recognize the form /dev/hda4,
  * but the suspend code would see the long name.)
  */
-static int is_resume_device(const struct swap_info_struct *swap_info)
+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;
@@ -294,54 +151,22 @@ static int is_resume_device(const struct swap_info_struct *swap_info)
 
 static int swsusp_swap_check(void) /* This is called before saving image */
 {
-        int i, len;
-
-        len=strlen(resume_file);
-        root_swap = 0xFFFF;
-
-        spin_lock(&swap_lock);
-        for (i=0; i<MAX_SWAPFILES; i++) {
-                if (!(swap_info[i].flags & SWP_WRITEOK)) {
-                        swapfile_used[i]=SWAPFILE_UNUSED;
-                } else {
-                        if (!len) {
-                                printk(KERN_WARNING "resume= option should be used to set suspend device" );
-                                if (root_swap == 0xFFFF) {
-                                        swapfile_used[i] = SWAPFILE_SUSPEND;
-                                        root_swap = i;
-                                } else
-                                        swapfile_used[i] = SWAPFILE_IGNORED;
-                        } else {
-                                /* we ignore all swap devices that are not the resume_file */
-                                if (is_resume_device(&swap_info[i])) {
-                                        swapfile_used[i] = SWAPFILE_SUSPEND;
-                                        root_swap = i;
-                                } else {
-                                        swapfile_used[i] = SWAPFILE_IGNORED;
-                                }
-                        }
-                }
-        }
-        spin_unlock(&swap_lock);
-        return (root_swap != 0xffff) ? 0 : -ENODEV;
-}
-
-/**
- * This is called after saving image so modification
- * will be lost after resume... and that's what we want.
- * we make the device unusable. A new call to
- * lock_swapdevices can unlock the devices.
- */
-static void lock_swapdevices(void)
-{
         int i;
 
+        if (!swsusp_resume_device)
+                return -ENODEV;
         spin_lock(&swap_lock);
-        for (i = 0; i< MAX_SWAPFILES; i++)
-                if (swapfile_used[i] == SWAPFILE_IGNORED) {
-                        swap_info[i].flags ^= SWP_WRITEOK;
+        for (i = 0; i < MAX_SWAPFILES; i++) {
+                if (!(swap_info[i].flags & SWP_WRITEOK))
+                        continue;
+                if (is_resume_device(swap_info + i)) {
+                        spin_unlock(&swap_lock);
+                        root_swap = i;
+                        return 0;
                 }
+        }
         spin_unlock(&swap_lock);
+        return -ENODEV;
 }
 
 /**
@@ -359,72 +184,217 @@ static void lock_swapdevices(void)
 static int write_page(unsigned long addr, swp_entry_t *loc)
 {
         swp_entry_t entry;
-        int error = 0;
+        int error = -ENOSPC;
 
-        entry = get_swap_page();
-        if (swp_offset(entry) &&
-            swapfile_used[swp_type(entry)] == SWAPFILE_SUSPEND) {
-                error = rw_swap_page_sync(WRITE, entry,
-                                          virt_to_page(addr));
-                if (error == -EIO)
-                        error = 0;
-                if (!error)
+        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;
-        } else
-                error = -ENOSPC;
+        }
         return error;
 }
 
 /**
- *      data_free - Free the swap entries used by the saved image.
+ *      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.
  *
- *      Walk the list of used swap entries and free each one.
- *      This is only used for cleanup when suspend fails.
+ *      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.
  */
-static void data_free(void)
+
+#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)
 {
-        swp_entry_t entry;
-        struct pbe *p;
+        struct swap_map_page *swp;
 
-        for_each_pbe (p, pagedir_nosave) {
-                entry = p->swap_address;
-                if (entry.val)
-                        swap_free(entry);
-                else
-                        break;
+        while (swap_map) {
+                swp = swap_map->next;
+                free_page((unsigned long)swap_map);
+                swap_map = swp;
         }
 }
 
+static struct swap_map_page *alloc_swap_map(unsigned int nr_pages)
+{
+        struct swap_map_page *swap_map, *swp;
+        unsigned n = 0;
+
+        if (!nr_pages)
+                return NULL;
+
+        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 swap_map;
+}
+
 /**
- *      data_write - Write saved image to swap.
- *
- *      Walk the list of pages in the image and sync each one to swap.
+ *      reverse_swap_map - reverse the order of pages in the swap map
+ *      @swap_map
  */
-static int data_write(void)
+
+static inline struct swap_map_page *reverse_swap_map(struct swap_map_page *swap_map)
 {
-        int error = 0, i = 0;
-        unsigned int mod = nr_copy_pages / 100;
-        struct pbe *p;
-        void *tfm;
+        struct swap_map_page *prev, *next;
+
+        prev = NULL;
+        while (swap_map) {
+                next = swap_map->next;
+                swap_map->next = prev;
+                prev = swap_map;
+                swap_map = next;
+        }
+        return prev;
+}
 
-        if ((error = crypto_init(1, &tfm)))
-                return error;
+/**
+ *      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;
+        }
+}
 
-        if (!mod)
-                mod = 1;
+/**
+ *      save_swap_map - save the swap map used for tracing the data pages
+ *      stored in the swap
+ */
 
-        printk( "Writing data to swap (%d pages)...     ", nr_copy_pages );
-        for_each_pbe (p, pagedir_nosave) {
-                if (!(i%mod))
-                        printk( "\b\b\b\b%3d%%", i / mod );
-                if ((error = crypto_write(p, tfm))) {
-                        crypto_exit(tfm);
+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;
-                }
-                i++;
+                swap_map = swap_map->next;
         }
-        printk("\b\b\b\bdone\n");
-        crypto_exit(tfm);
+        *start = entry;
+        return 0;
+}
+
+/**
+ *      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 k;
+
+        while (swp) {
+                for (k = 0; k < MAP_PAGE_SIZE; k++)
+                        if (swp->entries[k].val)
+                                swap_free(swp->entries[k]);
+                swp = swp->next;
+        }
+}
+
+/**
+ *      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;
 }
 
@@ -440,70 +410,70 @@ static void dump_info(void)
         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: Pagedir: %ld Pages\n",swsusp_info.pagedir_pages);
+        pr_debug(" swsusp: Total: %ld Pages\n", swsusp_info.pages);
 }
 
-static void init_header(void)
+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.suspend_pagedir = pagedir_nosave;
         swsusp_info.cpus = num_online_cpus();
-        swsusp_info.image_pages = nr_copy_pages;
-}
-
-static int close_swap(void)
-{
-        swp_entry_t entry;
-        int error;
-
-        dump_info();
-        error = write_page((unsigned long)&swsusp_info, &entry);
-        if (!error) {
-                printk( "S" );
-                error = mark_swapfiles(entry);
-                printk( "|\n" );
-        }
-        return error;
+        swsusp_info.image_pages = nr_pages;
+        swsusp_info.pages = nr_pages +
+                ((nr_pages * sizeof(long) + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
 }
 
 /**
- *      free_pagedir_entries - Free pages used by the page directory.
- *
- *      This is used during suspend for error recovery.
+ *      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 void free_pagedir_entries(void)
+static inline struct pbe *pack_orig_addresses(unsigned long *buf,
+                                              struct pbe *pbe)
 {
-        int i;
+        int j;
 
-        for (i = 0; i < swsusp_info.pagedir_pages; i++)
-                swap_free(swsusp_info.pagedir[i]);
+        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;
 }
 
-
 /**
- *      write_pagedir - Write the array of pages holding the page directory.
- *      @last:  Last swap entry we write (needed for header).
+ *      save_image_metadata - save the .orig_address fields of the PBEs
+ *      from the list @pblist using the swap map handle @handle
  */
 
-static int write_pagedir(void)
+static int save_image_metadata(struct pbe *pblist,
+                               struct swap_map_handle *handle)
 {
-        int error = 0;
+        unsigned long *buf;
         unsigned int n = 0;
-        struct pbe *pbe;
+        struct pbe *p;
+        int error = 0;
 
-        printk( "Writing pagedir...");
-        for_each_pb_page (pbe, pagedir_nosave) {
-                if ((error = write_page((unsigned long)pbe, &swsusp_info.pagedir[n++])))
-                        return error;
+        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++;
         }
-
-        swsusp_info.pagedir_pages = n;
-        printk("done (%u pages)\n", n);
+        free_page((unsigned long)buf);
+        if (!error)
+                printk("done (%u pages saved)\n", n);
         return error;
 }
 
@@ -511,75 +481,125 @@ static int write_pagedir(void)
  *      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.
- *
- *      FIXME: si_swapinfo(&i) returns all swap devices information.
- *      We should only consider resume_device.
+ *      space avaiable from the resume partition.
  */
 
 static int enough_swap(unsigned int nr_pages)
 {
-        struct sysinfo i;
+        unsigned int free_swap = swap_info[root_swap].pages -
+                swap_info[root_swap].inuse_pages;
 
-        si_swapinfo(&i);
-        pr_debug("swsusp: available swap: %lu pages\n", i.freeswap);
-        return i.freeswap > (nr_pages + PAGES_FOR_IO +
+        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);
 }
 
 /**
- *      write_suspend_image - Write entire image and metadata.
+ *      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.)
  */
-static int write_suspend_image(void)
+
+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 (!enough_swap(nr_copy_pages)) {
+        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();
-        if ((error = data_write()))
-                goto FreeData;
+        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;
 
-        if ((error = write_pagedir()))
-                goto FreePagedir;
+        swap_map = reverse_swap_map(swap_map);
+        error = save_swap_map(swap_map, &start);
+        if (error)
+                goto Free_map_entries;
 
-        if ((error = close_swap()))
-                goto FreePagedir;
- Done:
-        memset(key_iv, 0, MAXKEY+MAXIV);
+        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;
- FreePagedir:
-        free_pagedir_entries();
- FreeData:
-        data_free();
-        goto Done;
+
+Free_map_entries:
+        free_swap_map_entries(swap_map);
+Free_image_entries:
+        free_image_entries(swap_map);
+        goto Free_swap_map;
 }
 
-/* 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.)
+/**
+ *      swsusp_shrink_memory -  Try to free as much memory as needed
+ *
+ *      ... but do not OOM-kill anyone
+ *
+ *      Notice: all userland should be stopped before it is called, or
+ *      livelock is possible.
  */
-int swsusp_write(void)
-{
-        int error;
 
-        if ((error = swsusp_swap_check())) {
-                printk(KERN_ERR "swsusp: cannot find swap device, try swapon -a.\n");
-                return error;
-        }
-        lock_swapdevices();
-        error = write_suspend_image();
-        /* This will unlock ignored swap devices since writing is finished */
-        lock_swapdevices();
-        return error;
-}
+#define SHRINK_BITE     10000
 
+int swsusp_shrink_memory(void)
+{
+        long size, tmp;
+        struct zone *zone;
+        unsigned long pages = 0;
+        unsigned int i = 0;
+        char *p = "-\\|/";
+
+        printk("Shrinking memory...  ");
+        do {
+                size = 2 * count_highmem_pages();
+                size += size / 50 + count_data_pages();
+                size += (size + PBES_PER_PAGE - 1) / PBES_PER_PAGE +
+                        PAGES_FOR_IO;
+                tmp = size;
+                for_each_zone (zone)
+                        if (!is_highmem(zone))
+                                tmp -= zone->free_pages;
+                if (tmp > 0) {
+                        tmp = shrink_all_memory(SHRINK_BITE);
+                        if (!tmp)
+                                return -ENOMEM;
+                        pages += tmp;
+                } else if (size > (image_size * 1024 * 1024) / PAGE_SIZE) {
+                        tmp = shrink_all_memory(SHRINK_BITE);
+                        pages += tmp;
+                }
+                printk("\b%c", p[i++%4]);
+        } while (tmp > 0);
+        printk("\bdone (%lu pages freed)\n", pages);
 
+        return 0;
+}
 
 int swsusp_suspend(void)
 {
@@ -677,7 +697,6 @@ 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->swap_address = src->swap_address;
                 dst = dst->next;
                 src = src->next;
         }
@@ -757,198 +776,224 @@ static int bio_write_page(pgoff_t page_off, void *page)
         return submit(WRITE, page_off, page);
 }
 
-/*
- * Sanity check if this image makes sense with this kernel/swap context
- * I really don't think that it's foolproof but more than nothing..
+/**
+ *      The following functions allow us to read data using a swap map
+ *      in a file-alike way
  */
 
-static const char *sanity_check(void)
+static inline void release_swap_map_reader(struct swap_map_handle *handle)
 {
-        dump_info();
-        if (swsusp_info.version_code != LINUX_VERSION_CODE)
-                return "kernel version";
-        if (swsusp_info.num_physpages != num_physpages)
-                return "memory size";
-        if (strcmp(swsusp_info.uts.sysname,system_utsname.sysname))
-                return "system type";
-        if (strcmp(swsusp_info.uts.release,system_utsname.release))
-                return "kernel release";
-        if (strcmp(swsusp_info.uts.version,system_utsname.version))
-                return "version";
-        if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
-                return "machine";
-#if 0
-        /* We can't use number of online CPUs when we use hotplug to remove them ;-))) */
-        if (swsusp_info.cpus != num_possible_cpus())
-                return "number of cpus";
-#endif
-        return NULL;
+        if (handle->cur)
+                free_page((unsigned long)handle->cur);
+        handle->cur = NULL;
 }
 
-
-static int check_header(void)
+static inline int get_swap_map_reader(struct swap_map_handle *handle,
+                                      swp_entry_t start)
 {
-        const char *reason = NULL;
         int error;
 
-        if ((error = bio_read_page(swp_offset(swsusp_header.swsusp_info), &swsusp_info)))
+        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;
-
-        /* Is this same machine? */
-        if ((reason = sanity_check())) {
-                printk(KERN_ERR "swsusp: Resume mismatch: %s\n",reason);
-                return -EPERM;
         }
-        nr_copy_pages = swsusp_info.image_pages;
-        return error;
+        handle->k = 0;
+        return 0;
 }
 
-static int check_sig(void)
+static inline int swap_map_read_page(struct swap_map_handle *handle, void *buf)
 {
+        unsigned long offset;
         int error;
 
-        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);
-                memcpy(key_iv, swsusp_header.key_iv, MAXKEY+MAXIV);
-                memset(swsusp_header.key_iv, 0, MAXKEY+MAXIV);
-
-                /*
-                 * Reset swap signature now.
-                 */
-                error = bio_write_page(0, &swsusp_header);
-        } else {
+        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);
         }
-        if (!error)
-                pr_debug("swsusp: Signature found, resuming\n");
         return error;
 }
 
-/**
- *      data_read - Read image pages from swap.
- *
- *      You do not need to check for overlaps, check_pagedir()
- *      already did that.
- */
-
-static int data_read(struct pbe *pblist)
+static int check_header(void)
 {
-        struct pbe *p;
-        int error = 0;
-        int i = 0;
-        int mod = swsusp_info.image_pages / 100;
-        void *tfm;
-
-        if ((error = crypto_init(0, &tfm)))
-                return error;
-
-        if (!mod)
-                mod = 1;
-
-        printk("swsusp: Reading image data (%lu pages):     ",
-                        swsusp_info.image_pages);
-
-        for_each_pbe (p, pblist) {
-                if (!(i % mod))
-                        printk("\b\b\b\b%3d%%", i / mod);
+        char *reason = NULL;
 
-                if ((error = crypto_read(p, tfm))) {
-                        crypto_exit(tfm);
-                        return error;
-                }
-
-                i++;
+        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;
         }
-        printk("\b\b\b\bdone\n");
-        crypto_exit(tfm);
-        return error;
+        return 0;
 }
 
 /**
- *      read_pagedir - Read page backup list pages from swap
+ *      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 read_pagedir(struct pbe *pblist)
+static int load_image_data(struct pbe *pblist,
+                           struct swap_map_handle *handle,
+                           unsigned int nr_pages)
 {
-        struct pbe *pbpage, *p;
-        unsigned int i = 0;
         int error;
+        unsigned int m;
+        struct pbe *p;
 
         if (!pblist)
-                return -EFAULT;
-
-        printk("swsusp: Reading pagedir (%lu pages)\n",
-                        swsusp_info.pagedir_pages);
-
-        for_each_pb_page (pbpage, pblist) {
-                unsigned long offset = swp_offset(swsusp_info.pagedir[i++]);
-
-                error = -EFAULT;
-                if (offset) {
-                        p = (pbpage + PB_PAGE_SKIP)->next;
-                        error = bio_read_page(offset, (void *)pbpage);
-                        (pbpage + PB_PAGE_SKIP)->next = p;
-                }
+                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)
-                BUG_ON(i != swsusp_info.pagedir_pages);
-
+                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 int check_suspend_image(void)
+static inline struct pbe *unpack_orig_addresses(unsigned long *buf,
+                                                struct pbe *pbe)
 {
-        int error = 0;
+        int j;
 
-        if ((error = check_sig()))
-                return error;
-
-        if ((error = check_header()))
-                return error;
-
-        return 0;
+        for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
+                pbe->orig_address = buf[j];
+                pbe = pbe->next;
+        }
+        return pbe;
 }
 
-static int read_suspend_image(void)
+/**
+ *      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)
 {
-        int error = 0;
         struct pbe *p;
+        unsigned long *buf;
+        unsigned int n = 0;
+        int error = 0;
 
-        if (!(p = alloc_pagedir(nr_copy_pages, GFP_ATOMIC, 0)))
+        printk("Loading image metadata ... ");
+        buf = (unsigned long *)get_zeroed_page(GFP_ATOMIC);
+        if (!buf)
                 return -ENOMEM;
-
-        if ((error = read_pagedir(p)))
-                return error;
-        create_pbe_list(p, nr_copy_pages);
-        mark_unsafe_pages(p);
-        pagedir_nosave = alloc_pagedir(nr_copy_pages, GFP_ATOMIC, 1);
-        if (pagedir_nosave) {
-                create_pbe_list(pagedir_nosave, nr_copy_pages);
-                copy_page_backup_list(pagedir_nosave, p);
+        p = pblist;
+        while (p) {
+                error = swap_map_read_page(handle, buf);
+                if (error)
+                        break;
+                p = unpack_orig_addresses(buf, p);
+                n++;
         }
-        free_pagedir(p);
-        if (!pagedir_nosave)
-                return -ENOMEM;
+        free_page((unsigned long)buf);
+        if (!error)
+                printk("done (%u pages loaded)\n", n);
+        return error;
+}
 
-        /* Allocate memory for the image and read the data from swap */
+int swsusp_read(struct pbe **pblist_ptr)
+{
+        int error;
+        struct pbe *p, *pblist;
+        struct swap_map_handle handle;
+        unsigned int nr_pages;
 
-        error = alloc_data_pages(pagedir_nosave, GFP_ATOMIC, 1);
+        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 = data_read(pagedir_nosave);
+                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 saved image in swap
+ *      swsusp_check - Check for swsusp signature in the resume device
  */
 
 int swsusp_check(void)
@@ -958,40 +1003,27 @@ int swsusp_check(void)
         resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
         if (!IS_ERR(resume_bdev)) {
                 set_blocksize(resume_bdev, PAGE_SIZE);
-                error = check_suspend_image();
+                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
+                        blkdev_put(resume_bdev);
+                else
+                        pr_debug("swsusp: Signature found, resuming\n");
+        } else {
                 error = PTR_ERR(resume_bdev);
-
-        if (!error)
-                pr_debug("swsusp: resume file found\n");
-        else
-                pr_debug("swsusp: Error %d check for resume file\n", error);
-        return error;
-}
-
-/**
- *      swsusp_read - Read saved image from swap.
- */
-
-int swsusp_read(void)
-{
-        int error;
-
-        if (IS_ERR(resume_bdev)) {
-                pr_debug("swsusp: block device not initialised\n");
-                return PTR_ERR(resume_bdev);
         }
 
-        error = read_suspend_image();
-        blkdev_put(resume_bdev);
-        memset(key_iv, 0, MAXKEY+MAXIV);
+        if (error)
+                pr_debug("swsusp: Error %d check for resume file\n", error);
 
-        if (!error)
-                pr_debug("swsusp: Reading resume file was successful\n");
-        else
-                pr_debug("swsusp: Error %d resuming\n", error);
         return error;
 }