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-rw-r--r--kernel/power/snapshot.c1155
1 files changed, 801 insertions, 354 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 75d4886e648..1b84313cbab 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -34,10 +34,12 @@
#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;
+static void *buffer;
#ifdef CONFIG_HIGHMEM
unsigned int count_highmem_pages(void)
@@ -156,240 +158,637 @@ static inline int save_highmem(void) {return 0;}
static inline int restore_highmem(void) {return 0;}
#endif
-static int pfn_is_nosave(unsigned long pfn)
+/**
+ * @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)
{
- 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);
+ 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;
+}
+
+unsigned long get_safe_page(gfp_t gfp_mask)
+{
+ return (unsigned long)alloc_image_page(gfp_mask, PG_SAFE);
}
/**
- * saveable - Determine whether a page should be cloned or not.
- * @pfn: The page
- *
- * 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.
+ * free_image_page - free page represented by @addr, allocated with
+ * alloc_image_page (page flags set by it must be cleared)
*/
-static int saveable(struct zone *zone, unsigned long *zone_pfn)
+static inline void free_image_page(void *addr, int clear_nosave_free)
{
- unsigned long pfn = *zone_pfn + zone->zone_start_pfn;
- struct page *page;
+ ClearPageNosave(virt_to_page(addr));
+ if (clear_nosave_free)
+ ClearPageNosaveFree(virt_to_page(addr));
+ free_page((unsigned long)addr);
+}
- if (!pfn_valid(pfn))
- return 0;
+/* struct linked_page is used to build chains of pages */
- page = pfn_to_page(pfn);
- BUG_ON(PageReserved(page) && PageNosave(page));
- if (PageNosave(page))
- return 0;
- if (PageReserved(page) && pfn_is_nosave(pfn))
- return 0;
- if (PageNosaveFree(page))
- return 0;
+#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
- return 1;
-}
+struct linked_page {
+ struct linked_page *next;
+ char data[LINKED_PAGE_DATA_SIZE];
+} __attribute__((packed));
-unsigned int count_data_pages(void)
+static inline void
+free_list_of_pages(struct linked_page *list, int clear_page_nosave)
{
- struct zone *zone;
- unsigned long zone_pfn;
- unsigned int n = 0;
+ while (list) {
+ struct linked_page *lp = list->next;
- 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);
+ free_image_page(list, clear_page_nosave);
+ list = lp;
}
- return n;
}
-static void copy_data_pages(struct pbe *pblist)
+/**
+ * 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)
{
- struct zone *zone;
- unsigned long zone_pfn;
- struct pbe *pbe, *p;
+ ca->chain = NULL;
+ ca->used_space = LINKED_PAGE_DATA_SIZE;
+ ca->gfp_mask = gfp_mask;
+ ca->safe_needed = safe_needed;
+}
- pbe = pblist;
- for_each_zone (zone) {
- if (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;
- long *src, *dst;
- int n;
-
- page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
- BUG_ON(!pbe);
- pbe->orig_address = (unsigned long)page_address(page);
- /* copy_page and memcpy are not usable for copying task structs. */
- dst = (long *)pbe->address;
- src = (long *)pbe->orig_address;
- for (n = PAGE_SIZE / sizeof(long); n; n--)
- *dst++ = *src++;
- pbe = pbe->next;
- }
- }
+static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
+{
+ 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;
}
- BUG_ON(pbe);
+ ret = ca->chain->data + ca->used_space;
+ ca->used_space += size;
+ return ret;
}
+static void chain_free(struct chain_allocator *ca, int clear_page_nosave)
+{
+ free_list_of_pages(ca->chain, clear_page_nosave);
+ memset(ca, 0, sizeof(struct chain_allocator));
+}
/**
- * free_pagedir - free pages allocated with alloc_pagedir()
+ * 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 ;-).
+ *
+ * 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 void free_pagedir(struct pbe *pblist, int clear_nosave_free)
+#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)
{
- struct pbe *pbe;
+ bm->cur.chunk = 0;
+ bm->cur.bit = -1;
+}
- 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;
- }
+static void memory_bm_position_reset(struct memory_bitmap *bm)
+{
+ struct zone_bitmap *zone_bm;
+
+ 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);
+
/**
- * fill_pb_page - Create a list of PBEs on a given memory page
+ * create_bm_block_list - create a list of block bitmap objects
*/
-static inline void fill_pb_page(struct pbe *pbpage)
+static inline struct bm_block *
+create_bm_block_list(unsigned int nr_blocks, struct chain_allocator *ca)
{
- struct pbe *p;
+ struct bm_block *bblist = NULL;
+
+ while (nr_blocks-- > 0) {
+ struct bm_block *bb;
- p = pbpage;
- pbpage += PB_PAGE_SKIP;
- do
- p->next = p + 1;
- while (++p < pbpage);
+ bb = chain_alloc(ca, sizeof(struct bm_block));
+ if (!bb)
+ return NULL;
+
+ bb->next = bblist;
+ bblist = bb;
+ }
+ return bblist;
}
/**
- * create_pbe_list - Create a list of PBEs on top of a given chain
- * of memory pages allocated with alloc_pagedir()
+ * create_zone_bm_list - create a list of zone bitmap objects
*/
-static inline void create_pbe_list(struct pbe *pblist, unsigned int nr_pages)
+static inline struct zone_bitmap *
+create_zone_bm_list(unsigned int nr_zones, struct chain_allocator *ca)
{
- struct pbe *pbpage, *p;
- unsigned int num = PBES_PER_PAGE;
+ struct zone_bitmap *zbmlist = NULL;
- for_each_pb_page (pbpage, pblist) {
- if (num >= nr_pages)
- break;
+ 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 zbmlist;
+}
+
+/**
+ * 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;
+ struct zone_bitmap *zone_bm;
+ struct bm_block *bb;
+ unsigned int nr;
+
+ chain_init(&ca, gfp_mask, safe_needed);
- fill_pb_page(pbpage);
- num += PBES_PER_PAGE;
+ /* 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;
}
- if (pbpage) {
- for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++)
- p->next = p + 1;
- p->next = NULL;
+
+ /* Initialize the zone bitmap objects */
+ for_each_zone (zone) {
+ unsigned long pfn;
+
+ if (!populated_zone(zone) || is_highmem(zone))
+ continue;
+
+ 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;
}
+ 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;
}
-static unsigned int unsafe_pages;
+/**
+ * memory_bm_free - free memory occupied by the memory bitmap @bm
+ */
+
+static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
+{
+ 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;
+}
/**
- * @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_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.
*
- * The unsafe pages are marked with the PG_nosave_free flag
- * and we count them using unsafe_pages
+ * If the bit cannot be set, the function returns -EINVAL .
*/
-static inline void *alloc_image_page(gfp_t gfp_mask, int safe_needed)
+static int
+memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
{
- 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;
+
+ /* 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;
}
- if (res) {
- SetPageNosave(virt_to_page(res));
- SetPageNosaveFree(virt_to_page(res));
+ bm->cur.zone_bm = zone_bm;
}
- return res;
+ /* 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;
}
-unsigned long get_safe_page(gfp_t gfp_mask)
+/* Two auxiliary functions for memory_bm_next_pfn */
+
+/* Find the first set bit in the given chunk, if there is one */
+
+static inline int next_bit_in_chunk(int bit, unsigned long *chunk_p)
{
- return (unsigned long)alloc_image_page(gfp_mask, 1);
+ bit++;
+ while (bit < BM_BITS_PER_CHUNK) {
+ if (test_bit(bit, chunk_p))
+ return bit;
+
+ bit++;
+ }
+ return -1;
+}
+
+/* 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;
}
/**
- * alloc_pagedir - Allocate the page directory.
- *
- * First, determine exactly how many pages we need and
- * allocate them.
+ * 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.
*
- * 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.
+ * It is required to run memory_bm_position_reset() before the first call to
+ * this function.
+ */
+
+static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
+{
+ 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);
+ }
+ } 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;
+}
+
+/**
+ * pfn_is_nosave - check if given pfn is in the 'nosave' section
+ */
+
+static inline int pfn_is_nosave(unsigned long pfn)
+{
+ 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);
+}
+
+/**
+ * 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;
- 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);
+ 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);
}
- if (!pbe) { /* get_zeroed_page() failed */
- free_pagedir(pblist, 1);
- pblist = NULL;
- } else
- create_pbe_list(pblist, nr_pages);
- return pblist;
+ 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;
+
+ 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);
+ }
+ 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);
@@ -399,7 +798,7 @@ void swsusp_free(void)
}
nr_copy_pages = 0;
nr_meta_pages = 0;
- pagedir_nosave = NULL;
+ restore_pblist = NULL;
buffer = NULL;
}
@@ -414,46 +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;
@@ -464,25 +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,
@@ -511,22 +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;
}
/**
@@ -553,37 +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;
@@ -595,47 +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;
@@ -662,19 +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;
}
@@ -682,113 +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;
}
@@ -816,46 +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;
@@ -863,6 +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);
}