[PATCH] swsusp: rework swsusp_suspend

This patch makes only the functions in swsusp.c call functions in snapshot.c
and not both ways.   It also moves the check for available swap out of
swsusp_suspend() which is necessary for separating the swap-handling functions
in swsusp from the core code.

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

3 files changed, 47 insertions, 49 deletions

diff --git a/kernel/power/power.h b/kernel/power/power.h
index 893ee655085c..6c042b5ee14b 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -65,10 +65,8 @@ extern suspend_pagedir_t *pagedir_save;
 extern asmlinkage int swsusp_arch_suspend(void);
 extern asmlinkage int swsusp_arch_resume(void);
 
-extern int restore_highmem(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 int enough_swap(unsigned nr_pages);
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index b8a2e9a63206..4a6dbcefd378 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -88,8 +88,7 @@ static int save_highmem_zone(struct zone *zone)
         return 0;
 }
 
-
-static int save_highmem(void)
+int save_highmem(void)
 {
         struct zone *zone;
         int res = 0;
@@ -120,11 +119,7 @@ int restore_highmem(void)
         }
         return 0;
 }
-#else
-static int save_highmem(void) { return 0; }
-int restore_highmem(void) { return 0; }
-#endif /* CONFIG_HIGHMEM */
-
+#endif
 
 static int pfn_is_nosave(unsigned long pfn)
 {
@@ -416,11 +411,6 @@ asmlinkage int swsusp_save(void)
         unsigned int nr_pages;
 
         pr_debug("swsusp: critical section: \n");
-        if (save_highmem()) {
-                printk(KERN_CRIT "swsusp: Not enough free pages for highmem\n");
-                restore_highmem();
-                return -ENOMEM;
-        }
 
         drain_local_pages();
         nr_pages = count_data_pages();
@@ -440,11 +430,6 @@ asmlinkage int swsusp_save(void)
                 return -ENOMEM;
         }
 
-        if (!enough_swap(nr_pages)) {
-                printk(KERN_ERR "swsusp: Not enough free swap\n");
-                return -ENOSPC;
-        }
-
         pagedir_nosave = swsusp_alloc(nr_pages);
         if (!pagedir_nosave)
                 return -ENOMEM;
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index 8511c7f3386a..c05f46e7348f 100644
--- a/kernel/power/swsusp.c
+++ b/kernel/power/swsusp.c
@@ -73,6 +73,14 @@
 
 #include "power.h"
 
+#ifdef CONFIG_HIGHMEM
+int save_highmem(void);
+int restore_highmem(void);
+#else
+static int save_highmem(void) { return 0; }
+static int restore_highmem(void) { return 0; }
+#endif
+
 #define CIPHER "aes"
 #define MAXKEY 32
 #define MAXIV  32
@@ -500,6 +508,26 @@ static int write_pagedir(void)
 }
 
 /**
+ *      enough_swap - Make sure we have enough swap to save the image.
+ *
+ *      Returns TRUE or FALSE after checking the total amount of swap
+ *      space avaiable.
+ *
+ *      FIXME: si_swapinfo(&i) returns all swap devices information.
+ *      We should only consider resume_device.
+ */
+
+static int enough_swap(unsigned int nr_pages)
+{
+        struct sysinfo i;
+
+        si_swapinfo(&i);
+        pr_debug("swsusp: available swap: %lu pages\n", i.freeswap);
+        return i.freeswap > (nr_pages + PAGES_FOR_IO +
+                (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
+}
+
+/**
  *      write_suspend_image - Write entire image and metadata.
  *
  */
@@ -507,6 +535,11 @@ static int write_suspend_image(void)
 {
         int error;
 
+        if (!enough_swap(nr_copy_pages)) {
+                printk(KERN_ERR "swsusp: Not enough free swap\n");
+                return -ENOSPC;
+        }
+
         init_header();
         if ((error = data_write()))
                 goto FreeData;
@@ -526,27 +559,6 @@ static int write_suspend_image(void)
         goto Done;
 }
 
-/**
- *      enough_swap - Make sure we have enough swap to save the image.
- *
- *      Returns TRUE or FALSE after checking the total amount of swap
- *      space avaiable.
- *
- *      FIXME: si_swapinfo(&i) returns all swap devices information.
- *      We should only consider resume_device.
- */
-
-int enough_swap(unsigned int nr_pages)
-{
-        struct sysinfo i;
-
-        si_swapinfo(&i);
-        pr_debug("swsusp: available swap: %lu pages\n", i.freeswap);
-        return i.freeswap > (nr_pages + PAGES_FOR_IO +
-                (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
-}
-
-
 /* It is important _NOT_ to umount filesystems at this point. We want
  * them synced (in case something goes wrong) but we DO not want to mark
  * filesystem clean: it is not. (And it does not matter, if we resume
@@ -556,12 +568,15 @@ int swsusp_write(void)
 {
         int error;
 
+        if ((error = swsusp_swap_check())) {
+                printk(KERN_ERR "swsusp: cannot find swap device, try swapon -a.\n");
+                return error;
+        }
         lock_swapdevices();
         error = write_suspend_image();
         /* This will unlock ignored swap devices since writing is finished */
         lock_swapdevices();
         return error;
-
 }
 
 
@@ -569,6 +584,7 @@ int swsusp_write(void)
 int swsusp_suspend(void)
 {
         int error;
+
         if ((error = arch_prepare_suspend()))
                 return error;
         local_irq_disable();
@@ -580,15 +596,12 @@ int swsusp_suspend(void)
          */
         if ((error = device_power_down(PMSG_FREEZE))) {
                 printk(KERN_ERR "Some devices failed to power down, aborting suspend\n");
-                local_irq_enable();
-                return error;
+                goto Enable_irqs;
         }
 
-        if ((error = swsusp_swap_check())) {
-                printk(KERN_ERR "swsusp: cannot find swap device, try swapon -a.\n");
-                device_power_up();
-                local_irq_enable();
-                return error;
+        if ((error = save_highmem())) {
+                printk(KERN_ERR "swsusp: Not enough free pages for highmem\n");
+                goto Restore_highmem;
         }
 
         save_processor_state();
@@ -596,8 +609,10 @@ int swsusp_suspend(void)
                 printk(KERN_ERR "Error %d suspending\n", error);
         /* Restore control flow magically appears here */
         restore_processor_state();
+Restore_highmem:
         restore_highmem();
         device_power_up();
+Enable_irqs:
         local_irq_enable();
         return error;
 }
@@ -804,7 +819,7 @@ static int check_sig(void)
                  * Reset swap signature now.
                  */
                 error = bio_write_page(0, &swsusp_header);
-        } else { 
+        } else {
                 return -EINVAL;
         }
         if (!error)