[PATCH] swsusp: rework memory freeing on resume
The following patch makes swsusp use the PG_nosave and PG_nosave_free flags to
mark pages that should be freed in case of an error during resume.
This allows us to simplify the code and to use swsusp_free() in all of the
swsusp's resume error paths, which makes them actually work.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/suspend.c b/arch/x86_64/kernel/suspend.c
index 0251682..fd2bef7 100644
--- a/arch/x86_64/kernel/suspend.c
+++ b/arch/x86_64/kernel/suspend.c
@@ -147,57 +147,7 @@
pgd_t *temp_level4_pgt;
-static void **pages;
-
-static inline void *__add_page(void)
-{
- void **c;
-
- c = (void **)get_usable_page(GFP_ATOMIC);
- if (c) {
- *c = pages;
- pages = c;
- }
- return c;
-}
-
-static inline void *__next_page(void)
-{
- void **c;
-
- c = pages;
- if (c) {
- pages = *c;
- *c = NULL;
- }
- return c;
-}
-
-/*
- * Try to allocate as many usable pages as needed and daisy chain them.
- * If one allocation fails, free the pages allocated so far
- */
-static int alloc_usable_pages(unsigned long n)
-{
- void *p;
-
- pages = NULL;
- do
- if (!__add_page())
- break;
- while (--n);
- if (n) {
- p = __next_page();
- while (p) {
- free_page((unsigned long)p);
- p = __next_page();
- }
- return -ENOMEM;
- }
- return 0;
-}
-
-static void res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)
+static int res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)
{
long i, j;
@@ -211,7 +161,9 @@
if (paddr >= end)
break;
- pmd = (pmd_t *)__next_page();
+ pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
+ if (!pmd)
+ return -ENOMEM;
set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) {
unsigned long pe;
@@ -223,13 +175,17 @@
set_pmd(pmd, __pmd(pe));
}
}
+ return 0;
}
-static void set_up_temporary_mappings(void)
+static int set_up_temporary_mappings(void)
{
unsigned long start, end, next;
+ int error;
- temp_level4_pgt = (pgd_t *)__next_page();
+ temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);
+ if (!temp_level4_pgt)
+ return -ENOMEM;
/* It is safe to reuse the original kernel mapping */
set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
@@ -240,29 +196,27 @@
end = (unsigned long)pfn_to_kaddr(end_pfn);
for (; start < end; start = next) {
- pud_t *pud = (pud_t *)__next_page();
+ pud_t *pud = (pud_t *)get_safe_page(GFP_ATOMIC);
+ if (!pud)
+ return -ENOMEM;
next = start + PGDIR_SIZE;
if (next > end)
next = end;
- res_phys_pud_init(pud, __pa(start), __pa(next));
+ if ((error = res_phys_pud_init(pud, __pa(start), __pa(next))))
+ return error;
set_pgd(temp_level4_pgt + pgd_index(start),
mk_kernel_pgd(__pa(pud)));
}
+ return 0;
}
int swsusp_arch_resume(void)
{
- unsigned long n;
+ int error;
- n = ((end_pfn << PAGE_SHIFT) + PUD_SIZE - 1) >> PUD_SHIFT;
- n += (n + PTRS_PER_PUD - 1) / PTRS_PER_PUD + 1;
- pr_debug("swsusp_arch_resume(): pages needed = %lu\n", n);
- if (alloc_usable_pages(n)) {
- free_eaten_memory();
- return -ENOMEM;
- }
/* We have got enough memory and from now on we cannot recover */
- set_up_temporary_mappings();
+ if ((error = set_up_temporary_mappings()))
+ return error;
restore_image();
return 0;
}