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);
}
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);
/* Compute the number of zones */
nr = 0;
for_each_zone(zone)
if (populated_zone(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;
}
/* Initialize the zone bitmap objects */
for_each_zone(zone) {
unsigned long pfn;
if (!populated_zone(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 = get_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 int
prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
{
unsigned int nr_pages;
struct linked_page *sp_list, *lp;
int error;
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--;
}
/* 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--;
}
/* 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;
}
