[PATCH] swsusp: introduce the swap map structure

This patch introduces the swap map structure that can be used by swsusp for
keeping tracks of data pages written to the swap.   The structure itself is
described in a comment within the patch.

The overall idea is to reduce the amount of metadata written to the swap and
to write and read the image pages sequentially, in a file-alike way.  This
makes the swap-handling part of swsusp fairly independent of its
snapshot-handling part and will hopefully allow us to completely separate
these two parts in the future.

This patch is needed to remove the suspend image size limit imposed by the
limited size of the swsusp_info structure, which is essential for x86-64
systems with more than 512 MB of RAM.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 8 deletions

diff --git a/kernel/power/power.h b/kernel/power/power.h
index 6c042b5ee14b..977877c6dcfc 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -9,19 +9,14 @@
 #define SUSPEND_CONSOLE (MAX_NR_CONSOLES-1)
 #endif
 
-#define MAX_PBES        ((PAGE_SIZE - sizeof(struct new_utsname) \
-                        - 4 - 3*sizeof(unsigned long) - sizeof(int) \
-                        - sizeof(void *)) / sizeof(swp_entry_t))
-
 struct swsusp_info {
         struct new_utsname      uts;
         u32                     version_code;
         unsigned long           num_physpages;
         int                     cpus;
         unsigned long           image_pages;
-        unsigned long           pagedir_pages;
-        suspend_pagedir_t       * suspend_pagedir;
-        swp_entry_t             pagedir[MAX_PBES];
+        unsigned long           pages;
+        swp_entry_t             start;
 } __attribute__((aligned(PAGE_SIZE)));
 
 
@@ -67,6 +62,8 @@ extern asmlinkage int swsusp_arch_resume(void);
 
 extern void free_pagedir(struct pbe *pblist);
 extern struct pbe *alloc_pagedir(unsigned nr_pages, gfp_t gfp_mask, int safe_needed);
-extern void create_pbe_list(struct pbe *pblist, unsigned nr_pages);
 extern void swsusp_free(void);
 extern int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed);
+extern unsigned int snapshot_nr_pages(void);
+extern struct pbe *snapshot_pblist(void);
+extern void snapshot_pblist_set(struct pbe *pblist);