[PATCH 3/3] swsusp: Fix alloc_pagedir

Rafael J. Wysocki
2006-08-02T17:01:12Z

Get rid of the FIXME in kernel/power/snapshot.c#alloc_pagedir() and
simplify the functions called by it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
kernel/power/snapshot.c | 32 +++++++++++++++++---------------
1 file changed, 17 insertions(+), 15 deletions(-)

Index: linux-2.6.18-rc2-mm1/kernel/power/snapshot.c
===================================================================
--- linux-2.6.18-rc2-mm1.orig/kernel/power/snapshot.c 2006-08-01 22:15:41.000000000 +0200
+++ linux-2.6.18-rc2-mm1/kernel/power/snapshot.c 2006-08-01 22:24:57.000000000 +0200
@@ -316,12 +316,12 @@ static void free_pagedir(struct pbe *pbl
* fill_pb_page - Create a list of PBEs on a given memory page
*/

-static inline void fill_pb_page(struct pbe *pbpage)
+static inline void fill_pb_page(struct pbe *pbpage, unsigned int n)
{
struct pbe *p;

p = pbpage;
- pbpage += PB_PAGE_SKIP;
+ pbpage += n - 1;
do
p->next = p + 1;
while (++p < pbpage);
@@ -330,24 +330,26 @@ static inline void fill_pb_page(struct p
/**
* create_pbe_list - Create a list of PBEs on top of a given chain
* of memory pages allocated with alloc_pagedir()
+ *
+ * This function assumes that pages allocated by alloc_image_page() will
+ * always be zeroed.
*/

static inline void create_pbe_list(struct pbe *pblist, unsigned int nr_pages)
{
- struct pbe *pbpage, *p;
+ struct pbe *pbpage;
unsigned int num = PBES_PER_PAGE;

for_each_pb_page (pbpage, pblist) {
if (num >= nr_pages)
break;

- fill_pb_page(pbpage);
+ fill_pb_page(pbpage, PBES_PER_PAGE);
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;
+ num -= PBES_PER_PAGE;
+ fill_pb_page(pbpage, nr_pages - num);
}
}

@@ -374,17 +376,17 @@ static struct pbe *alloc_pagedir(unsigne
return NULL;

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 = pblist;
+ for (num = PBES_PER_PAGE; num < nr_pages; num += PBES_PER_PAGE) {
+ if (!pbe) {
+ free_pagedir(pblist, 1);
+ return NULL;
+ }
pbe += PB_PAGE_SKIP;
pbe->next = alloc_image_page(gfp_mask, safe_needed);
+ pbe = pbe->next;
}
- if (!pbe) { /* get_zeroed_page() failed */
- free_pagedir(pblist, 1);
- pblist = NULL;
- } else
- create_pbe_list(pblist, nr_pages);
+ create_pbe_list(pblist, nr_pages);
return pblist;
}