[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>

1 files changed, 45 insertions, 30 deletions

diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index 8511c7f..c05f46e 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)