1 files changed, 795 insertions, 446 deletions

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 3d9284100b22..1b84313cbab5 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -34,95 +34,15 @@
 
 #include "power.h"
 
-struct pbe *pagedir_nosave;
+/* List of PBEs used for creating and restoring the suspend image */
+struct pbe *restore_pblist;
+
 static unsigned int nr_copy_pages;
 static unsigned int nr_meta_pages;
-static unsigned long *buffer;
-
-struct arch_saveable_page {
-        unsigned long start;
-        unsigned long end;
-        char *data;
-        struct arch_saveable_page *next;
-};
-static struct arch_saveable_page *arch_pages;
-
-int swsusp_add_arch_pages(unsigned long start, unsigned long end)
-{
-        struct arch_saveable_page *tmp;
-
-        while (start < end) {
-                tmp = kzalloc(sizeof(struct arch_saveable_page), GFP_KERNEL);
-                if (!tmp)
-                        return -ENOMEM;
-                tmp->start = start;
-                tmp->end = ((start >> PAGE_SHIFT) + 1) << PAGE_SHIFT;
-                if (tmp->end > end)
-                        tmp->end = end;
-                tmp->next = arch_pages;
-                start = tmp->end;
-                arch_pages = tmp;
-        }
-        return 0;
-}
-
-static unsigned int count_arch_pages(void)
-{
-        unsigned int count = 0;
-        struct arch_saveable_page *tmp = arch_pages;
-        while (tmp) {
-                count++;
-                tmp = tmp->next;
-        }
-        return count;
-}
-
-static int save_arch_mem(void)
-{
-        char *kaddr;
-        struct arch_saveable_page *tmp = arch_pages;
-        int offset;
-
-        pr_debug("swsusp: Saving arch specific memory");
-        while (tmp) {
-                tmp->data = (char *)__get_free_page(GFP_ATOMIC);
-                if (!tmp->data)
-                        return -ENOMEM;
-                offset = tmp->start - (tmp->start & PAGE_MASK);
-                /* arch pages might haven't a 'struct page' */
-                kaddr = kmap_atomic_pfn(tmp->start >> PAGE_SHIFT, KM_USER0);
-                memcpy(tmp->data + offset, kaddr + offset,
-                        tmp->end - tmp->start);
-                kunmap_atomic(kaddr, KM_USER0);
-
-                tmp = tmp->next;
-        }
-        return 0;
-}
-
-static int restore_arch_mem(void)
-{
-        char *kaddr;
-        struct arch_saveable_page *tmp = arch_pages;
-        int offset;
-
-        while (tmp) {
-                if (!tmp->data)
-                        continue;
-                offset = tmp->start - (tmp->start & PAGE_MASK);
-                kaddr = kmap_atomic_pfn(tmp->start >> PAGE_SHIFT, KM_USER0);
-                memcpy(kaddr + offset, tmp->data + offset,
-                        tmp->end - tmp->start);
-                kunmap_atomic(kaddr, KM_USER0);
-                free_page((long)tmp->data);
-                tmp->data = NULL;
-                tmp = tmp->next;
-        }
-        return 0;
-}
+static void *buffer;
 
 #ifdef CONFIG_HIGHMEM
-static unsigned int count_highmem_pages(void)
+unsigned int count_highmem_pages(void)
 {
         struct zone *zone;
         unsigned long zone_pfn;
@@ -199,7 +119,7 @@ static int save_highmem_zone(struct zone *zone)
         return 0;
 }
 
-static int save_highmem(void)
+int save_highmem(void)
 {
         struct zone *zone;
         int res = 0;
@@ -216,7 +136,7 @@ static int save_highmem(void)
         return 0;
 }
 
-static int restore_highmem(void)
+int restore_highmem(void)
 {
         printk("swsusp: Restoring Highmem\n");
         while (highmem_copy) {
@@ -238,256 +158,637 @@ static inline int save_highmem(void) {return 0;}
 static inline int restore_highmem(void) {return 0;}
 #endif
 
-unsigned int count_special_pages(void)
+/**
+ *      @safe_needed - on resume, for storing the PBE list and the image,
+ *      we can only use memory pages that do not conflict with the pages
+ *      used before suspend.
+ *
+ *      The unsafe pages are marked with the PG_nosave_free flag
+ *      and we count them using unsafe_pages
+ */
+
+#define PG_ANY          0
+#define PG_SAFE         1
+#define PG_UNSAFE_CLEAR 1
+#define PG_UNSAFE_KEEP  0
+
+static unsigned int allocated_unsafe_pages;
+
+static void *alloc_image_page(gfp_t gfp_mask, int safe_needed)
 {
-        return count_arch_pages() + count_highmem_pages();
+        void *res;
+
+        res = (void *)get_zeroed_page(gfp_mask);
+        if (safe_needed)
+                while (res && PageNosaveFree(virt_to_page(res))) {
+                        /* The page is unsafe, mark it for swsusp_free() */
+                        SetPageNosave(virt_to_page(res));
+                        allocated_unsafe_pages++;
+                        res = (void *)get_zeroed_page(gfp_mask);
+                }
+        if (res) {
+                SetPageNosave(virt_to_page(res));
+                SetPageNosaveFree(virt_to_page(res));
+        }
+        return res;
 }
 
-int save_special_mem(void)
+unsigned long get_safe_page(gfp_t gfp_mask)
 {
-        int ret;
-        ret = save_arch_mem();
-        if (!ret)
-                ret = save_highmem();
-        return ret;
+        return (unsigned long)alloc_image_page(gfp_mask, PG_SAFE);
+}
+
+/**
+ *      free_image_page - free page represented by @addr, allocated with
+ *      alloc_image_page (page flags set by it must be cleared)
+ */
+
+static inline void free_image_page(void *addr, int clear_nosave_free)
+{
+        ClearPageNosave(virt_to_page(addr));
+        if (clear_nosave_free)
+                ClearPageNosaveFree(virt_to_page(addr));
+        free_page((unsigned long)addr);
+}
+
+/* struct linked_page is used to build chains of pages */
+
+#define LINKED_PAGE_DATA_SIZE   (PAGE_SIZE - sizeof(void *))
+
+struct linked_page {
+        struct linked_page *next;
+        char data[LINKED_PAGE_DATA_SIZE];
+} __attribute__((packed));
+
+static inline void
+free_list_of_pages(struct linked_page *list, int clear_page_nosave)
+{
+        while (list) {
+                struct linked_page *lp = list->next;
+
+                free_image_page(list, clear_page_nosave);
+                list = lp;
+        }
+}
+
+/**
+  *     struct chain_allocator is used for allocating small objects out of
+  *     a linked list of pages called 'the chain'.
+  *
+  *     The chain grows each time when there is no room for a new object in
+  *     the current page.  The allocated objects cannot be freed individually.
+  *     It is only possible to free them all at once, by freeing the entire
+  *     chain.
+  *
+  *     NOTE: The chain allocator may be inefficient if the allocated objects
+  *     are not much smaller than PAGE_SIZE.
+  */
+
+struct chain_allocator {
+        struct linked_page *chain;      /* the chain */
+        unsigned int used_space;        /* total size of objects allocated out
+                                         * of the current page
+                                         */
+        gfp_t gfp_mask;         /* mask for allocating pages */
+        int safe_needed;        /* if set, only "safe" pages are allocated */
+};
+
+static void
+chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed)
+{
+        ca->chain = NULL;
+        ca->used_space = LINKED_PAGE_DATA_SIZE;
+        ca->gfp_mask = gfp_mask;
+        ca->safe_needed = safe_needed;
 }
 
-int restore_special_mem(void)
+static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
 {
-        int ret;
-        ret = restore_arch_mem();
-        if (!ret)
-                ret = restore_highmem();
+        void *ret;
+
+        if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
+                struct linked_page *lp;
+
+                lp = alloc_image_page(ca->gfp_mask, ca->safe_needed);
+                if (!lp)
+                        return NULL;
+
+                lp->next = ca->chain;
+                ca->chain = lp;
+                ca->used_space = 0;
+        }
+        ret = ca->chain->data + ca->used_space;
+        ca->used_space += size;
         return ret;
 }
 
-static int pfn_is_nosave(unsigned long pfn)
+static void chain_free(struct chain_allocator *ca, int clear_page_nosave)
 {
-        unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
-        unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
-        return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
+        free_list_of_pages(ca->chain, clear_page_nosave);
+        memset(ca, 0, sizeof(struct chain_allocator));
 }
 
 /**
- *      saveable - Determine whether a page should be cloned or not.
- *      @pfn:   The page
+ *      Data types related to memory bitmaps.
+ *
+ *      Memory bitmap is a structure consiting of many linked lists of
+ *      objects.  The main list's elements are of type struct zone_bitmap
+ *      and each of them corresonds to one zone.  For each zone bitmap
+ *      object there is a list of objects of type struct bm_block that
+ *      represent each blocks of bit chunks in which information is
+ *      stored.
+ *
+ *      struct memory_bitmap contains a pointer to the main list of zone
+ *      bitmap objects, a struct bm_position used for browsing the bitmap,
+ *      and a pointer to the list of pages used for allocating all of the
+ *      zone bitmap objects and bitmap block objects.
+ *
+ *      NOTE: It has to be possible to lay out the bitmap in memory
+ *      using only allocations of order 0.  Additionally, the bitmap is
+ *      designed to work with arbitrary number of zones (this is over the
+ *      top for now, but let's avoid making unnecessary assumptions ;-).
  *
- *      We save a page if it's Reserved, and not in the range of pages
- *      statically defined as 'unsaveable', or if it isn't reserved, and
- *      isn't part of a free chunk of pages.
+ *      struct zone_bitmap contains a pointer to a list of bitmap block
+ *      objects and a pointer to the bitmap block object that has been
+ *      most recently used for setting bits.  Additionally, it contains the
+ *      pfns that correspond to the start and end of the represented zone.
+ *
+ *      struct bm_block contains a pointer to the memory page in which
+ *      information is stored (in the form of a block of bit chunks
+ *      of type unsigned long each).  It also contains the pfns that
+ *      correspond to the start and end of the represented memory area and
+ *      the number of bit chunks in the block.
+ *
+ *      NOTE: Memory bitmaps are used for two types of operations only:
+ *      "set a bit" and "find the next bit set".  Moreover, the searching
+ *      is always carried out after all of the "set a bit" operations
+ *      on given bitmap.
  */
 
-static int saveable(struct zone *zone, unsigned long *zone_pfn)
+#define BM_END_OF_MAP   (~0UL)
+
+#define BM_CHUNKS_PER_BLOCK     (PAGE_SIZE / sizeof(long))
+#define BM_BITS_PER_CHUNK       (sizeof(long) << 3)
+#define BM_BITS_PER_BLOCK       (PAGE_SIZE << 3)
+
+struct bm_block {
+        struct bm_block *next;          /* next element of the list */
+        unsigned long start_pfn;        /* pfn represented by the first bit */
+        unsigned long end_pfn;  /* pfn represented by the last bit plus 1 */
+        unsigned int size;      /* number of bit chunks */
+        unsigned long *data;    /* chunks of bits representing pages */
+};
+
+struct zone_bitmap {
+        struct zone_bitmap *next;       /* next element of the list */
+        unsigned long start_pfn;        /* minimal pfn in this zone */
+        unsigned long end_pfn;          /* maximal pfn in this zone plus 1 */
+        struct bm_block *bm_blocks;     /* list of bitmap blocks */
+        struct bm_block *cur_block;     /* recently used bitmap block */
+};
+
+/* strcut bm_position is used for browsing memory bitmaps */
+
+struct bm_position {
+        struct zone_bitmap *zone_bm;
+        struct bm_block *block;
+        int chunk;
+        int bit;
+};
+
+struct memory_bitmap {
+        struct zone_bitmap *zone_bm_list;       /* list of zone bitmaps */
+        struct linked_page *p_list;     /* list of pages used to store zone
+                                         * bitmap objects and bitmap block
+                                         * objects
+                                         */
+        struct bm_position cur; /* most recently used bit position */
+};
+
+/* Functions that operate on memory bitmaps */
+
+static inline void memory_bm_reset_chunk(struct memory_bitmap *bm)
 {
-        unsigned long pfn = *zone_pfn + zone->zone_start_pfn;
-        struct page *page;
+        bm->cur.chunk = 0;
+        bm->cur.bit = -1;
+}
 
-        if (!pfn_valid(pfn))
-                return 0;
+static void memory_bm_position_reset(struct memory_bitmap *bm)
+{
+        struct zone_bitmap *zone_bm;
 
-        page = pfn_to_page(pfn);
-        if (PageNosave(page))
-                return 0;
-        if (PageReserved(page) && pfn_is_nosave(pfn))
-                return 0;
-        if (PageNosaveFree(page))
-                return 0;
+        zone_bm = bm->zone_bm_list;
+        bm->cur.zone_bm = zone_bm;
+        bm->cur.block = zone_bm->bm_blocks;
+        memory_bm_reset_chunk(bm);
+}
+
+static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
 
-        return 1;
+/**
+ *      create_bm_block_list - create a list of block bitmap objects
+ */
+
+static inline struct bm_block *
+create_bm_block_list(unsigned int nr_blocks, struct chain_allocator *ca)
+{
+        struct bm_block *bblist = NULL;
+
+        while (nr_blocks-- > 0) {
+                struct bm_block *bb;
+
+                bb = chain_alloc(ca, sizeof(struct bm_block));
+                if (!bb)
+                        return NULL;
+
+                bb->next = bblist;
+                bblist = bb;
+        }
+        return bblist;
 }
 
-unsigned int count_data_pages(void)
+/**
+ *      create_zone_bm_list - create a list of zone bitmap objects
+ */
+
+static inline struct zone_bitmap *
+create_zone_bm_list(unsigned int nr_zones, struct chain_allocator *ca)
 {
-        struct zone *zone;
-        unsigned long zone_pfn;
-        unsigned int n = 0;
+        struct zone_bitmap *zbmlist = NULL;
 
-        for_each_zone (zone) {
-                if (is_highmem(zone))
-                        continue;
-                mark_free_pages(zone);
-                for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
-                        n += saveable(zone, &zone_pfn);
+        while (nr_zones-- > 0) {
+                struct zone_bitmap *zbm;
+
+                zbm = chain_alloc(ca, sizeof(struct zone_bitmap));
+                if (!zbm)
+                        return NULL;
+
+                zbm->next = zbmlist;
+                zbmlist = zbm;
         }
-        return n;
+        return zbmlist;
 }
 
-static void copy_data_pages(struct pbe *pblist)
+/**
+  *     memory_bm_create - allocate memory for a memory bitmap
+  */
+
+static int
+memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed)
 {
+        struct chain_allocator ca;
         struct zone *zone;
-        unsigned long zone_pfn;
-        struct pbe *pbe, *p;
+        struct zone_bitmap *zone_bm;
+        struct bm_block *bb;
+        unsigned int nr;
+
+        chain_init(&ca, gfp_mask, safe_needed);
+
+        /* Compute the number of zones */
+        nr = 0;
+        for_each_zone (zone)
+                if (populated_zone(zone) && !is_highmem(zone))
+                        nr++;
+
+        /* Allocate the list of zones bitmap objects */
+        zone_bm = create_zone_bm_list(nr, &ca);
+        bm->zone_bm_list = zone_bm;
+        if (!zone_bm) {
+                chain_free(&ca, PG_UNSAFE_CLEAR);
+                return -ENOMEM;
+        }
 
-        pbe = pblist;
+        /* Initialize the zone bitmap objects */
         for_each_zone (zone) {
-                if (is_highmem(zone))
+                unsigned long pfn;
+
+                if (!populated_zone(zone) || is_highmem(zone))
                         continue;
-                mark_free_pages(zone);
-                /* This is necessary for swsusp_free() */
-                for_each_pb_page (p, pblist)
-                        SetPageNosaveFree(virt_to_page(p));
-                for_each_pbe (p, pblist)
-                        SetPageNosaveFree(virt_to_page(p->address));
-                for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
-                        if (saveable(zone, &zone_pfn)) {
-                                struct page *page;
-                                page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
-                                BUG_ON(!pbe);
-                                pbe->orig_address = (unsigned long)page_address(page);
-                                /* copy_page is not usable for copying task structs. */
-                                memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE);
-                                pbe = pbe->next;
+
+                zone_bm->start_pfn = zone->zone_start_pfn;
+                zone_bm->end_pfn = zone->zone_start_pfn + zone->spanned_pages;
+                /* Allocate the list of bitmap block objects */
+                nr = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
+                bb = create_bm_block_list(nr, &ca);
+                zone_bm->bm_blocks = bb;
+                zone_bm->cur_block = bb;
+                if (!bb)
+                        goto Free;
+
+                nr = zone->spanned_pages;
+                pfn = zone->zone_start_pfn;
+                /* Initialize the bitmap block objects */
+                while (bb) {
+                        unsigned long *ptr;
+
+                        ptr = alloc_image_page(gfp_mask, safe_needed);
+                        bb->data = ptr;
+                        if (!ptr)
+                                goto Free;
+
+                        bb->start_pfn = pfn;
+                        if (nr >= BM_BITS_PER_BLOCK) {
+                                pfn += BM_BITS_PER_BLOCK;
+                                bb->size = BM_CHUNKS_PER_BLOCK;
+                                nr -= BM_BITS_PER_BLOCK;
+                        } else {
+                                /* This is executed only once in the loop */
+                                pfn += nr;
+                                bb->size = DIV_ROUND_UP(nr, BM_BITS_PER_CHUNK);
                         }
+                        bb->end_pfn = pfn;
+                        bb = bb->next;
                 }
+                zone_bm = zone_bm->next;
         }
-        BUG_ON(pbe);
-}
+        bm->p_list = ca.chain;
+        memory_bm_position_reset(bm);
+        return 0;
 
+Free:
+        bm->p_list = ca.chain;
+        memory_bm_free(bm, PG_UNSAFE_CLEAR);
+        return -ENOMEM;
+}
 
 /**
- *      free_pagedir - free pages allocated with alloc_pagedir()
- */
+  *     memory_bm_free - free memory occupied by the memory bitmap @bm
+  */
 
-static void free_pagedir(struct pbe *pblist, int clear_nosave_free)
+static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
 {
-        struct pbe *pbe;
-
-        while (pblist) {
-                pbe = (pblist + PB_PAGE_SKIP)->next;
-                ClearPageNosave(virt_to_page(pblist));
-                if (clear_nosave_free)
-                        ClearPageNosaveFree(virt_to_page(pblist));
-                free_page((unsigned long)pblist);
-                pblist = pbe;
+        struct zone_bitmap *zone_bm;
+
+        /* Free the list of bit blocks for each zone_bitmap object */
+        zone_bm = bm->zone_bm_list;
+        while (zone_bm) {
+                struct bm_block *bb;
+
+                bb = zone_bm->bm_blocks;
+                while (bb) {
+                        if (bb->data)
+                                free_image_page(bb->data, clear_nosave_free);
+                        bb = bb->next;
+                }
+                zone_bm = zone_bm->next;
         }
+        free_list_of_pages(bm->p_list, clear_nosave_free);
+        bm->zone_bm_list = NULL;
 }
 
 /**
- *      fill_pb_page - Create a list of PBEs on a given memory page
+ *      memory_bm_set_bit - set the bit in the bitmap @bm that corresponds
+ *      to given pfn.  The cur_zone_bm member of @bm and the cur_block member
+ *      of @bm->cur_zone_bm are updated.
+ *
+ *      If the bit cannot be set, the function returns -EINVAL .
  */
 
-static inline void fill_pb_page(struct pbe *pbpage)
+static int
+memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
 {
-        struct pbe *p;
-
-        p = pbpage;
-        pbpage += PB_PAGE_SKIP;
-        do
-                p->next = p + 1;
-        while (++p < pbpage);
+        struct zone_bitmap *zone_bm;
+        struct bm_block *bb;
+
+        /* Check if the pfn is from the current zone */
+        zone_bm = bm->cur.zone_bm;
+        if (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
+                zone_bm = bm->zone_bm_list;
+                /* We don't assume that the zones are sorted by pfns */
+                while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
+                        zone_bm = zone_bm->next;
+                        if (unlikely(!zone_bm))
+                                return -EINVAL;
+                }
+                bm->cur.zone_bm = zone_bm;
+        }
+        /* Check if the pfn corresponds to the current bitmap block */
+        bb = zone_bm->cur_block;
+        if (pfn < bb->start_pfn)
+                bb = zone_bm->bm_blocks;
+
+        while (pfn >= bb->end_pfn) {
+                bb = bb->next;
+                if (unlikely(!bb))
+                        return -EINVAL;
+        }
+        zone_bm->cur_block = bb;
+        pfn -= bb->start_pfn;
+        set_bit(pfn % BM_BITS_PER_CHUNK, bb->data + pfn / BM_BITS_PER_CHUNK);
+        return 0;
 }
 
-/**
- *      create_pbe_list - Create a list of PBEs on top of a given chain
- *      of memory pages allocated with alloc_pagedir()
- */
+/* Two auxiliary functions for memory_bm_next_pfn */
 
-static inline void create_pbe_list(struct pbe *pblist, unsigned int nr_pages)
-{
-        struct pbe *pbpage, *p;
-        unsigned int num = PBES_PER_PAGE;
+/* Find the first set bit in the given chunk, if there is one */
 
-        for_each_pb_page (pbpage, pblist) {
-                if (num >= nr_pages)
-                        break;
+static inline int next_bit_in_chunk(int bit, unsigned long *chunk_p)
+{
+        bit++;
+        while (bit < BM_BITS_PER_CHUNK) {
+                if (test_bit(bit, chunk_p))
+                        return bit;
 
-                fill_pb_page(pbpage);
-                num += PBES_PER_PAGE;
-        }
-        if (pbpage) {
-                for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++)
-                        p->next = p + 1;
-                p->next = NULL;
+                bit++;
         }
+        return -1;
 }
 
-static unsigned int unsafe_pages;
+/* Find a chunk containing some bits set in given block of bits */
+
+static inline int next_chunk_in_block(int n, struct bm_block *bb)
+{
+        n++;
+        while (n < bb->size) {
+                if (bb->data[n])
+                        return n;
+
+                n++;
+        }
+        return -1;
+}
 
 /**
- *      @safe_needed - on resume, for storing the PBE list and the image,
- *      we can only use memory pages that do not conflict with the pages
- *      used before suspend.
+ *      memory_bm_next_pfn - find the pfn that corresponds to the next set bit
+ *      in the bitmap @bm.  If the pfn cannot be found, BM_END_OF_MAP is
+ *      returned.
  *
- *      The unsafe pages are marked with the PG_nosave_free flag
- *      and we count them using unsafe_pages
+ *      It is required to run memory_bm_position_reset() before the first call to
+ *      this function.
  */
 
-static inline void *alloc_image_page(gfp_t gfp_mask, int safe_needed)
+static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
 {
-        void *res;
-
-        res = (void *)get_zeroed_page(gfp_mask);
-        if (safe_needed)
-                while (res && PageNosaveFree(virt_to_page(res))) {
-                        /* The page is unsafe, mark it for swsusp_free() */
-                        SetPageNosave(virt_to_page(res));
-                        unsafe_pages++;
-                        res = (void *)get_zeroed_page(gfp_mask);
+        struct zone_bitmap *zone_bm;
+        struct bm_block *bb;
+        int chunk;
+        int bit;
+
+        do {
+                bb = bm->cur.block;
+                do {
+                        chunk = bm->cur.chunk;
+                        bit = bm->cur.bit;
+                        do {
+                                bit = next_bit_in_chunk(bit, bb->data + chunk);
+                                if (bit >= 0)
+                                        goto Return_pfn;
+
+                                chunk = next_chunk_in_block(chunk, bb);
+                                bit = -1;
+                        } while (chunk >= 0);
+                        bb = bb->next;
+                        bm->cur.block = bb;
+                        memory_bm_reset_chunk(bm);
+                } while (bb);
+                zone_bm = bm->cur.zone_bm->next;
+                if (zone_bm) {
+                        bm->cur.zone_bm = zone_bm;
+                        bm->cur.block = zone_bm->bm_blocks;
+                        memory_bm_reset_chunk(bm);
                 }
-        if (res) {
-                SetPageNosave(virt_to_page(res));
-                SetPageNosaveFree(virt_to_page(res));
-        }
+        } while (zone_bm);
+        memory_bm_position_reset(bm);
+        return BM_END_OF_MAP;
+
+Return_pfn:
+        bm->cur.chunk = chunk;
+        bm->cur.bit = bit;
+        return bb->start_pfn + chunk * BM_BITS_PER_CHUNK + bit;
+}
+
+/**
+ *      snapshot_additional_pages - estimate the number of additional pages
+ *      be needed for setting up the suspend image data structures for given
+ *      zone (usually the returned value is greater than the exact number)
+ */
+
+unsigned int snapshot_additional_pages(struct zone *zone)
+{
+        unsigned int res;
+
+        res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
+        res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE);
         return res;
 }
 
-unsigned long get_safe_page(gfp_t gfp_mask)
+/**
+ *      pfn_is_nosave - check if given pfn is in the 'nosave' section
+ */
+
+static inline int pfn_is_nosave(unsigned long pfn)
 {
-        return (unsigned long)alloc_image_page(gfp_mask, 1);
+        unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
+        unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
+        return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
 }
 
 /**
- *      alloc_pagedir - Allocate the page directory.
- *
- *      First, determine exactly how many pages we need and
- *      allocate them.
- *
- *      We arrange the pages in a chain: each page is an array of PBES_PER_PAGE
- *      struct pbe elements (pbes) and the last element in the page points
- *      to the next page.
+ *      saveable - Determine whether a page should be cloned or not.
+ *      @pfn:   The page
  *
- *      On each page we set up a list of struct_pbe elements.
+ *      We save a page if it isn't Nosave, and is not in the range of pages
+ *      statically defined as 'unsaveable', and it
+ *      isn't a part of a free chunk of pages.
  */
 
-static struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask,
-                                 int safe_needed)
+static struct page *saveable_page(unsigned long pfn)
 {
-        unsigned int num;
-        struct pbe *pblist, *pbe;
+        struct page *page;
+
+        if (!pfn_valid(pfn))
+                return NULL;
 
-        if (!nr_pages)
+        page = pfn_to_page(pfn);
+
+        if (PageNosave(page))
+                return NULL;
+        if (PageReserved(page) && pfn_is_nosave(pfn))
                 return NULL;
+        if (PageNosaveFree(page))
+                return NULL;
+
+        return page;
+}
+
+unsigned int count_data_pages(void)
+{
+        struct zone *zone;
+        unsigned long pfn, max_zone_pfn;
+        unsigned int n = 0;
+
+        for_each_zone (zone) {
+                if (is_highmem(zone))
+                        continue;
+                mark_free_pages(zone);
+                max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
+                for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+                        n += !!saveable_page(pfn);
+        }
+        return n;
+}
+
+static inline void copy_data_page(long *dst, long *src)
+{
+        int n;
+
+        /* copy_page and memcpy are not usable for copying task structs. */
+        for (n = PAGE_SIZE / sizeof(long); n; n--)
+                *dst++ = *src++;
+}
+
+static void
+copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
+{
+        struct zone *zone;
+        unsigned long pfn;
+
+        for_each_zone (zone) {
+                unsigned long max_zone_pfn;
 
-        pblist = alloc_image_page(gfp_mask, safe_needed);
-        /* FIXME: rewrite this ugly loop */
-        for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages;
-                        pbe = pbe->next, num += PBES_PER_PAGE) {
-                pbe += PB_PAGE_SKIP;
-                pbe->next = alloc_image_page(gfp_mask, safe_needed);
+                if (is_highmem(zone))
+                        continue;
+
+                mark_free_pages(zone);
+                max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
+                for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+                        if (saveable_page(pfn))
+                                memory_bm_set_bit(orig_bm, pfn);
         }
-        if (!pbe) { /* get_zeroed_page() failed */
-                free_pagedir(pblist, 1);
-                pblist = NULL;
-        } else
-                create_pbe_list(pblist, nr_pages);
-        return pblist;
+        memory_bm_position_reset(orig_bm);
+        memory_bm_position_reset(copy_bm);
+        do {
+                pfn = memory_bm_next_pfn(orig_bm);
+                if (likely(pfn != BM_END_OF_MAP)) {
+                        struct page *page;
+                        void *src;
+
+                        page = pfn_to_page(pfn);
+                        src = page_address(page);
+                        page = pfn_to_page(memory_bm_next_pfn(copy_bm));
+                        copy_data_page(page_address(page), src);
+                }
+        } while (pfn != BM_END_OF_MAP);
 }
 
 /**
- * Free pages we allocated for suspend. Suspend pages are alocated
- * before atomic copy, so we need to free them after resume.
+ *      swsusp_free - free pages allocated for the suspend.
+ *
+ *      Suspend pages are alocated before the atomic copy is made, so we
+ *      need to release them after the resume.
  */
 
 void swsusp_free(void)
 {
         struct zone *zone;
-        unsigned long zone_pfn;
+        unsigned long pfn, max_zone_pfn;
 
         for_each_zone(zone) {
-                for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
-                        if (pfn_valid(zone_pfn + zone->zone_start_pfn)) {
-                                struct page *page;
-                                page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
+                max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
+                for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+                        if (pfn_valid(pfn)) {
+                                struct page *page = pfn_to_page(pfn);
+
                                 if (PageNosave(page) && PageNosaveFree(page)) {
                                         ClearPageNosave(page);
                                         ClearPageNosaveFree(page);
@@ -497,7 +798,7 @@ void swsusp_free(void)
         }
         nr_copy_pages = 0;
         nr_meta_pages = 0;
-        pagedir_nosave = NULL;
+        restore_pblist = NULL;
         buffer = NULL;
 }
 
@@ -512,46 +813,57 @@ void swsusp_free(void)
 static int enough_free_mem(unsigned int nr_pages)
 {
         struct zone *zone;
-        unsigned int n = 0;
+        unsigned int free = 0, meta = 0;
 
         for_each_zone (zone)
-                if (!is_highmem(zone))
-                        n += zone->free_pages;
-        pr_debug("swsusp: available memory: %u pages\n", n);
-        return n > (nr_pages + PAGES_FOR_IO +
-                (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
-}
+                if (!is_highmem(zone)) {
+                        free += zone->free_pages;
+                        meta += snapshot_additional_pages(zone);
+                }
 
-static int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed)
-{
-        struct pbe *p;
+        pr_debug("swsusp: pages needed: %u + %u + %u, available pages: %u\n",
+                nr_pages, PAGES_FOR_IO, meta, free);
 
-        for_each_pbe (p, pblist) {
-                p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed);
-                if (!p->address)
-                        return -ENOMEM;
-        }
-        return 0;
+        return free > nr_pages + PAGES_FOR_IO + meta;
 }
 
-static struct pbe *swsusp_alloc(unsigned int nr_pages)
+static int
+swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm,
+                unsigned int nr_pages)
 {
-        struct pbe *pblist;
+        int error;
 
-        if (!(pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, 0))) {
-                printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
-                return NULL;
-        }
+        error = memory_bm_create(orig_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
+        if (error)
+                goto Free;
 
-        if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, 0)) {
-                printk(KERN_ERR "suspend: Allocating image pages failed.\n");
-                swsusp_free();
-                return NULL;
+        error = memory_bm_create(copy_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
+        if (error)
+                goto Free;
+
+        while (nr_pages-- > 0) {
+                struct page *page = alloc_page(GFP_ATOMIC | __GFP_COLD);
+                if (!page)
+                        goto Free;
+
+                SetPageNosave(page);
+                SetPageNosaveFree(page);
+                memory_bm_set_bit(copy_bm, page_to_pfn(page));
         }
+        return 0;
 
-        return pblist;
+Free:
+        swsusp_free();
+        return -ENOMEM;
 }
 
+/* Memory bitmap used for marking saveable pages */
+static struct memory_bitmap orig_bm;
+/* Memory bitmap used for marking allocated pages that will contain the copies
+ * of saveable pages
+ */
+static struct memory_bitmap copy_bm;
+
 asmlinkage int swsusp_save(void)
 {
         unsigned int nr_pages;
@@ -562,25 +874,19 @@ asmlinkage int swsusp_save(void)
         nr_pages = count_data_pages();
         printk("swsusp: Need to copy %u pages\n", nr_pages);
 
-        pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
-                 nr_pages,
-                 (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE,
-                 PAGES_FOR_IO, nr_free_pages());
-
         if (!enough_free_mem(nr_pages)) {
                 printk(KERN_ERR "swsusp: Not enough free memory\n");
                 return -ENOMEM;
         }
 
-        pagedir_nosave = swsusp_alloc(nr_pages);
-        if (!pagedir_nosave)
+        if (swsusp_alloc(&orig_bm, &copy_bm, nr_pages))
                 return -ENOMEM;
 
         /* During allocating of suspend pagedir, new cold pages may appear.
          * Kill them.
          */
         drain_local_pages();
-        copy_data_pages(pagedir_nosave);
+        copy_data_pages(&copy_bm, &orig_bm);
 
         /*
          * End of critical section. From now on, we can write to memory,
@@ -609,22 +915,20 @@ static void init_header(struct swsusp_info *info)
 }
 
 /**
- *      pack_orig_addresses - the .orig_address fields of the PBEs from the
- *      list starting at @pbe are stored in the array @buf[] (1 page)
+ *      pack_pfns - pfns corresponding to the set bits found in the bitmap @bm
+ *      are stored in the array @buf[] (1 page at a time)
  */
 
-static inline struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pbe)
+static inline void
+pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
 {
         int j;
 
-        for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
-                buf[j] = pbe->orig_address;
-                pbe = pbe->next;
+        for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
+                buf[j] = memory_bm_next_pfn(bm);
+                if (unlikely(buf[j] == BM_END_OF_MAP))
+                        break;
         }
-        if (!pbe)
-                for (; j < PAGE_SIZE / sizeof(long); j++)
-                        buf[j] = 0;
-        return pbe;
 }
 
 /**
@@ -651,37 +955,39 @@ static inline struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pb
 
 int snapshot_read_next(struct snapshot_handle *handle, size_t count)
 {
-        if (handle->page > nr_meta_pages + nr_copy_pages)
+        if (handle->cur > nr_meta_pages + nr_copy_pages)
                 return 0;
+
         if (!buffer) {
                 /* This makes the buffer be freed by swsusp_free() */
-                buffer = alloc_image_page(GFP_ATOMIC, 0);
+                buffer = alloc_image_page(GFP_ATOMIC, PG_ANY);
                 if (!buffer)
                         return -ENOMEM;
         }
         if (!handle->offset) {
                 init_header((struct swsusp_info *)buffer);
                 handle->buffer = buffer;
-                handle->pbe = pagedir_nosave;
+                memory_bm_position_reset(&orig_bm);
+                memory_bm_position_reset(&copy_bm);
         }
-        if (handle->prev < handle->page) {
-                if (handle->page <= nr_meta_pages) {
-                        handle->pbe = pack_orig_addresses(buffer, handle->pbe);
-                        if (!handle->pbe)
-                                handle->pbe = pagedir_nosave;
+        if (handle->prev < handle->cur) {
+                if (handle->cur <= nr_meta_pages) {
+                        memset(buffer, 0, PAGE_SIZE);
+                        pack_pfns(buffer, &orig_bm);
                 } else {
-                        handle->buffer = (void *)handle->pbe->address;
-                        handle->pbe = handle->pbe->next;
+                        unsigned long pfn = memory_bm_next_pfn(&copy_bm);
+
+                        handle->buffer = page_address(pfn_to_page(pfn));
                 }
-                handle->prev = handle->page;
+                handle->prev = handle->cur;
         }
-        handle->buf_offset = handle->page_offset;
-        if (handle->page_offset + count >= PAGE_SIZE) {
-                count = PAGE_SIZE - handle->page_offset;
-                handle->page_offset = 0;
-                handle->page++;
+        handle->buf_offset = handle->cur_offset;
+        if (handle->cur_offset + count >= PAGE_SIZE) {
+                count = PAGE_SIZE - handle->cur_offset;
+                handle->cur_offset = 0;
+                handle->cur++;
         } else {
-                handle->page_offset += count;
+                handle->cur_offset += count;
         }
         handle->offset += count;
         return count;
@@ -693,47 +999,50 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
  *      had been used before suspend
  */
 
-static int mark_unsafe_pages(struct pbe *pblist)
+static int mark_unsafe_pages(struct memory_bitmap *bm)
 {
         struct zone *zone;
-        unsigned long zone_pfn;
-        struct pbe *p;
-
-        if (!pblist) /* a sanity check */
-                return -EINVAL;
+        unsigned long pfn, max_zone_pfn;
 
         /* 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));
+                max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
+                for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+                        if (pfn_valid(pfn))
+                                ClearPageNosaveFree(pfn_to_page(pfn));
         }
 
-        /* Mark orig addresses */
-        for_each_pbe (p, pblist) {
-                if (virt_addr_valid(p->orig_address))
-                        SetPageNosaveFree(virt_to_page(p->orig_address));
-                else
-                        return -EFAULT;
-        }
+        /* Mark pages that correspond to the "original" pfns as "unsafe" */
+        memory_bm_position_reset(bm);
+        do {
+                pfn = memory_bm_next_pfn(bm);
+                if (likely(pfn != BM_END_OF_MAP)) {
+                        if (likely(pfn_valid(pfn)))
+                                SetPageNosaveFree(pfn_to_page(pfn));
+                        else
+                                return -EFAULT;
+                }
+        } while (pfn != BM_END_OF_MAP);
 
-        unsafe_pages = 0;
+        allocated_unsafe_pages = 0;
 
         return 0;
 }
 
-static void copy_page_backup_list(struct pbe *dst, struct pbe *src)
+static void
+duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *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;
+        unsigned long pfn;
+
+        memory_bm_position_reset(src);
+        pfn = memory_bm_next_pfn(src);
+        while (pfn != BM_END_OF_MAP) {
+                memory_bm_set_bit(dst, pfn);
+                pfn = memory_bm_next_pfn(src);
         }
 }
 
-static int check_header(struct swsusp_info *info)
+static inline int check_header(struct swsusp_info *info)
 {
         char *reason = NULL;
 
@@ -760,19 +1069,14 @@ static int check_header(struct swsusp_info *info)
  *      load header - check the image header and copy data from it
  */
 
-static int load_header(struct snapshot_handle *handle,
-                              struct swsusp_info *info)
+static int
+load_header(struct swsusp_info *info)
 {
         int error;
-        struct pbe *pblist;
 
+        restore_pblist = NULL;
         error = check_header(info);
         if (!error) {
-                pblist = alloc_pagedir(info->image_pages, GFP_ATOMIC, 0);
-                if (!pblist)
-                        return -ENOMEM;
-                pagedir_nosave = pblist;
-                handle->pbe = pblist;
                 nr_copy_pages = info->image_pages;
                 nr_meta_pages = info->pages - info->image_pages - 1;
         }
@@ -780,113 +1084,137 @@ static int load_header(struct snapshot_handle *handle,
 }
 
 /**
- *      unpack_orig_addresses - copy the elements of @buf[] (1 page) to
- *      the PBEs in the list starting at @pbe
+ *      unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
+ *      the corresponding bit in the memory bitmap @bm
  */
 
-static inline struct pbe *unpack_orig_addresses(unsigned long *buf,
-                                                struct pbe *pbe)
+static inline void
+unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
 {
         int j;
 
-        for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
-                pbe->orig_address = buf[j];
-                pbe = pbe->next;
+        for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
+                if (unlikely(buf[j] == BM_END_OF_MAP))
+                        break;
+
+                memory_bm_set_bit(bm, buf[j]);
         }
-        return pbe;
 }
 
 /**
- *      prepare_image - use metadata contained in the PBE list
- *      pointed to by pagedir_nosave to mark the pages that will
- *      be overwritten in the process of restoring the system
- *      memory state from the image ("unsafe" pages) and allocate
- *      memory for the image
+ *      prepare_image - use the memory bitmap @bm to mark the pages that will
+ *      be overwritten in the process of restoring the system memory state
+ *      from the suspend image ("unsafe" pages) and allocate memory for the
+ *      image.
  *
- *      The idea is to allocate the PBE list first and then
- *      allocate as many pages as it's needed for the image data,
- *      but not to assign these pages to the PBEs initially.
- *      Instead, we just mark them as allocated and create a list
- *      of "safe" which will be used later
+ *      The idea is to allocate a new memory bitmap first and then allocate
+ *      as many pages as needed for the image data, but not to assign these
+ *      pages to specific tasks initially.  Instead, we just mark them as
+ *      allocated and create a list of "safe" pages that will be used later.
  */
 
-struct safe_page {
-        struct safe_page *next;
-        char padding[PAGE_SIZE - sizeof(void *)];
-};
+#define PBES_PER_LINKED_PAGE    (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
 
-static struct safe_page *safe_pages;
+static struct linked_page *safe_pages_list;
 
-static int prepare_image(struct snapshot_handle *handle)
+static int
+prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
 {
-        int error = 0;
-        unsigned int nr_pages = nr_copy_pages;
-        struct pbe *p, *pblist = NULL;
+        unsigned int nr_pages;
+        struct linked_page *sp_list, *lp;
+        int error;
 
-        p = pagedir_nosave;
-        error = mark_unsafe_pages(p);
-        if (!error) {
-                pblist = alloc_pagedir(nr_pages, GFP_ATOMIC, 1);
-                if (pblist)
-                        copy_page_backup_list(pblist, p);
-                free_pagedir(p, 0);
-                if (!pblist)
+        error = mark_unsafe_pages(bm);
+        if (error)
+                goto Free;
+
+        error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
+        if (error)
+                goto Free;
+
+        duplicate_memory_bitmap(new_bm, bm);
+        memory_bm_free(bm, PG_UNSAFE_KEEP);
+        /* Reserve some safe pages for potential later use.
+         *
+         * NOTE: This way we make sure there will be enough safe pages for the
+         * chain_alloc() in get_buffer().  It is a bit wasteful, but
+         * nr_copy_pages cannot be greater than 50% of the memory anyway.
+         */
+        sp_list = NULL;
+        /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */
+        nr_pages = nr_copy_pages - allocated_unsafe_pages;
+        nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
+        while (nr_pages > 0) {
+                lp = alloc_image_page(GFP_ATOMIC, PG_SAFE);
+                if (!lp) {
                         error = -ENOMEM;
+                        goto Free;
+                }
+                lp->next = sp_list;
+                sp_list = lp;
+                nr_pages--;
         }
-        safe_pages = NULL;
-        if (!error && nr_pages > unsafe_pages) {
-                nr_pages -= unsafe_pages;
-                while (nr_pages--) {
-                        struct safe_page *ptr;
-
-                        ptr = (struct safe_page *)get_zeroed_page(GFP_ATOMIC);
-                        if (!ptr) {
-                                error = -ENOMEM;
-                                break;
-                        }
-                        if (!PageNosaveFree(virt_to_page(ptr))) {
-                                /* The page is "safe", add it to the list */
-                                ptr->next = safe_pages;
-                                safe_pages = ptr;
-                        }
-                        /* Mark the page as allocated */
-                        SetPageNosave(virt_to_page(ptr));
-                        SetPageNosaveFree(virt_to_page(ptr));
+        /* Preallocate memory for the image */
+        safe_pages_list = NULL;
+        nr_pages = nr_copy_pages - allocated_unsafe_pages;
+        while (nr_pages > 0) {
+                lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
+                if (!lp) {
+                        error = -ENOMEM;
+                        goto Free;
+                }
+                if (!PageNosaveFree(virt_to_page(lp))) {
+                        /* The page is "safe", add it to the list */
+                        lp->next = safe_pages_list;
+                        safe_pages_list = lp;
                 }
+                /* Mark the page as allocated */
+                SetPageNosave(virt_to_page(lp));
+                SetPageNosaveFree(virt_to_page(lp));
+                nr_pages--;
         }
-        if (!error) {
-                pagedir_nosave = pblist;
-        } else {
-                handle->pbe = NULL;
-                swsusp_free();
+        /* Free the reserved safe pages so that chain_alloc() can use them */
+        while (sp_list) {
+                lp = sp_list->next;
+                free_image_page(sp_list, PG_UNSAFE_CLEAR);
+                sp_list = lp;
         }
+        return 0;
+
+Free:
+        swsusp_free();
         return error;
 }
 
-static void *get_buffer(struct snapshot_handle *handle)
+/**
+ *      get_buffer - compute the address that snapshot_write_next() should
+ *      set for its caller to write to.
+ */
+
+static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
 {
-        struct pbe *pbe = handle->pbe, *last = handle->last_pbe;
-        struct page *page = virt_to_page(pbe->orig_address);
+        struct pbe *pbe;
+        struct page *page = pfn_to_page(memory_bm_next_pfn(bm));
 
-        if (PageNosave(page) && PageNosaveFree(page)) {
-                /*
-                 * We have allocated the "original" page frame and we can
-                 * use it directly to store the read page
+        if (PageNosave(page) && PageNosaveFree(page))
+                /* We have allocated the "original" page frame and we can
+                 * use it directly to store the loaded page.
                  */
-                pbe->address = 0;
-                if (last && last->next)
-                        last->next = NULL;
-                return (void *)pbe->orig_address;
-        }
-        /*
-         * The "original" page frame has not been allocated and we have to
-         * use a "safe" page frame to store the read page
+                return page_address(page);
+
+        /* The "original" page frame has not been allocated and we have to
+         * use a "safe" page frame to store the loaded page.
          */
-        pbe->address = (unsigned long)safe_pages;
-        safe_pages = safe_pages->next;
-        if (last)
-                last->next = pbe;
-        handle->last_pbe = pbe;
+        pbe = chain_alloc(ca, sizeof(struct pbe));
+        if (!pbe) {
+                swsusp_free();
+                return NULL;
+        }
+        pbe->orig_address = (unsigned long)page_address(page);
+        pbe->address = (unsigned long)safe_pages_list;
+        safe_pages_list = safe_pages_list->next;
+        pbe->next = restore_pblist;
+        restore_pblist = pbe;
         return (void *)pbe->address;
 }
 
@@ -914,46 +1242,60 @@ static void *get_buffer(struct snapshot_handle *handle)
 
 int snapshot_write_next(struct snapshot_handle *handle, size_t count)
 {
+        static struct chain_allocator ca;
         int error = 0;
 
-        if (handle->prev && handle->page > nr_meta_pages + nr_copy_pages)
+        /* Check if we have already loaded the entire image */
+        if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages)
                 return 0;
+
         if (!buffer) {
                 /* This makes the buffer be freed by swsusp_free() */
-                buffer = alloc_image_page(GFP_ATOMIC, 0);
+                buffer = alloc_image_page(GFP_ATOMIC, PG_ANY);
                 if (!buffer)
                         return -ENOMEM;
         }
         if (!handle->offset)
                 handle->buffer = buffer;
-        if (handle->prev < handle->page) {
-                if (!handle->prev) {
-                        error = load_header(handle, (struct swsusp_info *)buffer);
+        handle->sync_read = 1;
+        if (handle->prev < handle->cur) {
+                if (handle->prev == 0) {
+                        error = load_header(buffer);
+                        if (error)
+                                return error;
+
+                        error = memory_bm_create(&copy_bm, GFP_ATOMIC, PG_ANY);
                         if (error)
                                 return error;
+
                 } else if (handle->prev <= nr_meta_pages) {
-                        handle->pbe = unpack_orig_addresses(buffer, handle->pbe);
-                        if (!handle->pbe) {
-                                error = prepare_image(handle);
+                        unpack_orig_pfns(buffer, &copy_bm);
+                        if (handle->prev == nr_meta_pages) {
+                                error = prepare_image(&orig_bm, &copy_bm);
                                 if (error)
                                         return error;
-                                handle->pbe = pagedir_nosave;
-                                handle->last_pbe = NULL;
-                                handle->buffer = get_buffer(handle);
+
+                                chain_init(&ca, GFP_ATOMIC, PG_SAFE);
+                                memory_bm_position_reset(&orig_bm);
+                                restore_pblist = NULL;
+                                handle->buffer = get_buffer(&orig_bm, &ca);
+                                handle->sync_read = 0;
+                                if (!handle->buffer)
+                                        return -ENOMEM;
                         }
                 } else {
-                        handle->pbe = handle->pbe->next;
-                        handle->buffer = get_buffer(handle);
+                        handle->buffer = get_buffer(&orig_bm, &ca);
+                        handle->sync_read = 0;
                 }
-                handle->prev = handle->page;
+                handle->prev = handle->cur;
         }
-        handle->buf_offset = handle->page_offset;
-        if (handle->page_offset + count >= PAGE_SIZE) {
-                count = PAGE_SIZE - handle->page_offset;
-                handle->page_offset = 0;
-                handle->page++;
+        handle->buf_offset = handle->cur_offset;
+        if (handle->cur_offset + count >= PAGE_SIZE) {
+                count = PAGE_SIZE - handle->cur_offset;
+                handle->cur_offset = 0;
+                handle->cur++;
         } else {
-                handle->page_offset += count;
+                handle->cur_offset += count;
         }
         handle->offset += count;
         return count;
@@ -961,6 +1303,13 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
 
 int snapshot_image_loaded(struct snapshot_handle *handle)
 {
-        return !(!handle->pbe || handle->pbe->next || !nr_copy_pages ||
-                handle->page <= nr_meta_pages + nr_copy_pages);
+        return !(!nr_copy_pages ||
+                        handle->cur <= nr_meta_pages + nr_copy_pages);
+}
+
+void snapshot_free_unused_memory(struct snapshot_handle *handle)
+{
+        /* Free only if we have loaded the image entirely */
+        if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages)
+                memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
 }