[PATCH] swsusp: fix error handling and cleanups

Drop printing during normal boot (when no image exists in swap), print
message when drivers fail, fix error paths and consolidate near-identical
functions in disk.c (and functions with just one statement).

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/power/disk.c

@@ -112,24 +112,12 @@ static inline void platform_finish(void)
 	}
 }
 
-static void finish(void)
-{
-	device_resume();
-	platform_finish();
-	thaw_processes();
-	enable_nonboot_cpus();
-	pm_restore_console();
-}
-
-
 static int prepare_processes(void)
 {
 	int error;
 
 	pm_prepare_console();
-
 	sys_sync();
-
 	disable_nonboot_cpus();
 
 	if (freeze_processes()) {
@@ -162,15 +150,6 @@ static void unprepare_processes(void)
 	pm_restore_console();
 }
 
-static int prepare_devices(void)
-{
-	int error;
-
-	if ((error = device_suspend(PMSG_FREEZE)))
-		printk("Some devices failed to suspend\n");
-	return error;
-}
-
 /**
  *	pm_suspend_disk - The granpappy of power management.
  *
@@ -187,17 +166,14 @@ int pm_suspend_disk(void)
 	error = prepare_processes();
 	if (error)
 		return error;
-	error = prepare_devices();
 
+	error = device_suspend(PMSG_FREEZE);
 	if (error) {
+		printk("Some devices failed to suspend\n");
 		unprepare_processes();
 		return error;
 	}
 
-	pr_debug("PM: Attempting to suspend to disk.\n");
-	if (pm_disk_mode == PM_DISK_FIRMWARE)
-		return pm_ops->enter(PM_SUSPEND_DISK);
-
 	pr_debug("PM: snapshotting memory.\n");
 	in_suspend = 1;
 	if ((error = swsusp_suspend()))
@@ -208,11 +184,20 @@ int pm_suspend_disk(void)
 		error = swsusp_write();
 		if (!error)
 			power_down(pm_disk_mode);
+		else {
+		/* swsusp_write can not fail in device_resume,
+		   no need to do second device_resume */
+			swsusp_free();
+			unprepare_processes();
+			return error;
+		}
 	} else
 		pr_debug("PM: Image restored successfully.\n");
+
 	swsusp_free();
  Done:
-	finish();
+	device_resume();
+	unprepare_processes();
 	return error;
 }
 
@@ -274,15 +259,17 @@ static int software_resume(void)
 
 	pr_debug("PM: Preparing devices for restore.\n");
 
-	if ((error = prepare_devices()))
+	if ((error = device_suspend(PMSG_FREEZE))) {
+		printk("Some devices failed to suspend\n");
 		goto Free;
+	}
 
 	mb();
 
 	pr_debug("PM: Restoring saved image.\n");
 	swsusp_resume();
 	pr_debug("PM: Restore failed, recovering.n");
-	finish();
+	device_resume();
  Free:
 	swsusp_free();
  Cleanup:

kernel/power/swsusp.c

@@ -530,7 +530,6 @@ static int write_pagedir(void)
  *	write_suspend_image - Write entire image and metadata.
  *
  */
-
 static int write_suspend_image(void)
 {
 	int error;
@@ -1021,20 +1020,21 @@ int swsusp_suspend(void)
 	 * at resume time, and evil weirdness ensues.
 	 */
 	if ((error = device_power_down(PMSG_FREEZE))) {
+		printk(KERN_ERR "Some devices failed to power down, aborting suspend\n");
 		local_irq_enable();
 		return error;
 	}
 
 	if ((error = swsusp_swap_check())) {
-		printk(KERN_ERR "swsusp: FATAL: cannot find swap device, try "
+		printk(KERN_ERR "swsusp: cannot find swap device, try swapon -a.\n");
-				"swapon -a!\n");
+		device_power_up();
 		local_irq_enable();
 		return error;
 	}
 
 	save_processor_state();
 	if ((error = swsusp_arch_suspend()))
-		printk("Error %d suspending\n", error);
+		printk(KERN_ERR "Error %d suspending\n", error);
 	/* Restore control flow magically appears here */
 	restore_processor_state();
 	BUG_ON (nr_copy_pages_check != nr_copy_pages);
@@ -1314,7 +1314,8 @@ static const char * sanity_check(void)
 	if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
 		return "machine";
 #if 0
-	if(swsusp_info.cpus != num_online_cpus())
+	/* We can't use number of online CPUs when we use hotplug to remove them ;-))) */
+	if (swsusp_info.cpus != num_possible_cpus())
 		return "number of cpus";
 #endif
 	return NULL;
@@ -1355,7 +1356,6 @@ static int check_sig(void)
 		 */
 		error = bio_write_page(0, &swsusp_header);
 	} else { 
-		printk(KERN_ERR "swsusp: Suspend partition has wrong signature?\n");
 		return -EINVAL;
 	}
 	if (!error)