swsusp: allow resume from initramfs

From: Pavel Machek
Date: Fri Mar 04 2005 - 05:23:08 EST

Hi!

From: mjg59@xxxxxxxxxxxxx

When using a fully modularized kernel it is necessary to activate
resume manually as the device node might not be available during
kernel init.

This patch implements a new sysfs attribute '/sys/power/resume' which
allows for manual activation of software resume. When read from it
prints the configured resume device in 'major:minor' format. When
written to it expects a device in 'major:minor' format. This device
is then checked for a suspended image and resume is started if a valid
image is found. The original functionality is left in place.

It should be used very carefully. I'll submit docs what that means;
usage from initramfs should be okay.

Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
Signed-off-by: Pavel Machek <pavel@xxxxxxx>

Please apply,
Pavel

--- linux.middle//include/linux/suspend.h 2005-02-14 14:14:21.000000000 +0100
+++ linux/include/linux/suspend.h 2005-03-03 13:23:17.000000000 +0100
@@ -35,6 +35,8 @@


#define SUSPEND_PD_PAGES(x) (((x)*sizeof(struct pbe))/PAGE_SIZE+1)
+
+extern dev_t swsusp_resume_device;

/* mm/vmscan.c */
extern int shrink_mem(void);
--- linux.middle//init/do_mounts.c 2005-02-03 22:28:15.000000000 +0100
+++ linux/init/do_mounts.c 2005-03-03 13:23:17.000000000 +0100
@@ -53,7 +53,7 @@
__setup("ro", readonly);
__setup("rw", readwrite);

-static dev_t __init try_name(char *name, int part)
+static dev_t try_name(char *name, int part)
{
char path[64];
char buf[32];
@@ -135,7 +135,7 @@
* is mounted on rootfs /sys.
*/

-dev_t __init name_to_dev_t(char *name)
+dev_t name_to_dev_t(char *name)
{
char s[32];
char *p;
--- linux.middle//kernel/power/disk.c 2005-03-02 00:22:49.000000000 +0100
+++ linux/kernel/power/disk.c 2005-03-04 10:15:46.000000000 +0100
@@ -16,7 +18,6 @@
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/fs.h>
-#include <linux/device.h>
#include "power.h"


@@ -25,13 +26,16 @@

extern int swsusp_suspend(void);
extern int swsusp_write(void);
+extern int swsusp_check(void);
extern int swsusp_read(void);
+extern void swsusp_close(void);
extern int swsusp_resume(void);
extern int swsusp_free(void);


static int noresume = 0;
char resume_file[256] = CONFIG_PM_STD_PARTITION;
+dev_t swsusp_resume_device;

/**
* power_down - Shut machine down for hibernate.
@@ -123,45 +127,54 @@
}


-static int prepare(void)
+static int prepare_processes(void)
{
int error;

pm_prepare_console();

sys_sync();
+
if (freeze_processes()) {
error = -EBUSY;
- goto Thaw;
+ return error;
}

if (pm_disk_mode == PM_DISK_PLATFORM) {
if (pm_ops && pm_ops->prepare) {
if ((error = pm_ops->prepare(PM_SUSPEND_DISK)))
- goto Thaw;
+ return error;
}
}

/* Free memory before shutting down devices. */
free_some_memory();

+ return 0;
+}
+
+static void unprepare_processes(void)
+{
+ enable_nonboot_cpus();
+ thaw_processes();
+ pm_restore_console();
+}
+
+static int prepare_devices(void)
+{
+ int error;
+
disable_nonboot_cpus();
if ((error = device_suspend(PMSG_FREEZE))) {
printk("Some devices failed to suspend\n");
- goto Finish;
+ platform_finish();
+ enable_nonboot_cpus();
+ return error;
}

return 0;
- Finish:
- platform_finish();
- Thaw:
- enable_nonboot_cpus();
- thaw_processes();
- pm_restore_console();
- return error;
}

-
/**
* pm_suspend_disk - The granpappy of power management.
*
@@ -175,8 +188,15 @@
{
int error;

- if ((error = prepare()))
+ error = prepare_processes();
+ if (!error) {
+ error = prepare_devices();
+ }
+
+ if (error) {
+ unprepare_processes();
return error;
+ }

pr_debug("PM: Attempting to suspend to disk.\n");
if (pm_disk_mode == PM_DISK_FIRMWARE)
@@ -225,14 +245,26 @@
return 0;
}

+ pr_debug("PM: Checking swsusp image.\n");
+
+ if ((error = swsusp_check()))
+ goto Done;
+
+ pr_debug("PM: Preparing processes for restore.\n");
+
+ if ((error = prepare_processes())) {
+ swsusp_close();
+ goto Cleanup;
+ }
+
pr_debug("PM: Reading swsusp image.\n");

if ((error = swsusp_read()))
- goto Done;
+ goto Cleanup;

- pr_debug("PM: Preparing system for restore.\n");
+ pr_debug("PM: Preparing devices for restore.\n");

- if ((error = prepare()))
+ if ((error = prepare_devices()))
goto Free;

barrier();
@@ -244,6 +276,8 @@
finish();
Free:
swsusp_free();
+ Cleanup:
+ unprepare_processes();
Done:
pr_debug("PM: Resume from disk failed.\n");
return 0;
@@ -331,8 +365,41 @@

power_attr(disk);

+static ssize_t resume_show(struct subsystem * subsys, char *buf)
+{
+ return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
+ MINOR(swsusp_resume_device));
+}
+
+static ssize_t resume_store(struct subsystem * subsys, const char * buf, size_t n)
+{
+ int len;
+ char *p;
+ unsigned int maj, min;
+ int error = -EINVAL;
+ dev_t res;
+
+ p = memchr(buf, '\n', n);
+ len = p ? p - buf : n;
+
+ if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
+ res = MKDEV(maj,min);
+ if (maj == MAJOR(res) && min == MINOR(res)) {
+ swsusp_resume_device = res;
+ printk("Attempting manual resume\n");
+ noresume = 0;
+ software_resume();
+ }
+ }
+
+ return error >= 0 ? n : error;
+}
+
+power_attr(resume);
+
static struct attribute * g[] = {
&disk_attr.attr,
+ &resume_attr.attr,
NULL,
};

--- linux.middle//kernel/power/swsusp.c 2005-02-28 21:29:06.000000000 +0100
+++ linux/kernel/power/swsusp.c 2005-03-03 13:35:52.000000000 +0100
@@ -79,7 +79,7 @@
static int nr_copy_pages_check;

extern char resume_file[];
-static dev_t resume_device;
+
/* Local variables that should not be affected by save */
unsigned int nr_copy_pages __nosavedata = 0;

@@ -169,7 +169,7 @@
struct inode *inode = file->f_dentry->d_inode;

return S_ISBLK(inode->i_mode) &&
- resume_device == MKDEV(imajor(inode), iminor(inode));
+ swsusp_resume_device == MKDEV(imajor(inode), iminor(inode));
}

static int swsusp_swap_check(void) /* This is called before saving image */
@@ -942,7 +942,7 @@
/*
* Returns true if given address/order collides with any orig_address
*/
-static int __init does_collide_order(unsigned long addr, int order)
+static int does_collide_order(unsigned long addr, int order)
{
int i;

@@ -975,7 +975,7 @@
*eaten_memory = c;
}

-static unsigned long __init get_usable_page(unsigned gfp_mask)
+static unsigned long get_usable_page(unsigned gfp_mask)
{
unsigned long m;

@@ -989,7 +989,7 @@
return m;
}

-static void __init free_eaten_memory(void)
+static void free_eaten_memory(void)
{
unsigned long m;
void **c;
@@ -1012,7 +1012,7 @@
* pages later
*/

-static int __init check_pagedir(struct pbe *pblist)
+static int check_pagedir(struct pbe *pblist)
{
struct pbe *p;

@@ -1036,7 +1036,7 @@
* restore from the loaded pages later. We relocate them here.
*/

-static struct pbe * __init swsusp_pagedir_relocate(struct pbe *pblist)
+static struct pbe * swsusp_pagedir_relocate(struct pbe *pblist)
{
struct zone *zone;
unsigned long zone_pfn;
@@ -1185,7 +1185,7 @@
* I really don't think that it's foolproof but more than nothing..
*/

-static const char * __init sanity_check(void)
+static const char * sanity_check(void)
{
dump_info();
if(swsusp_info.version_code != LINUX_VERSION_CODE)
@@ -1206,7 +1206,7 @@
}


-static int __init check_header(void)
+static int check_header(void)
{
const char * reason = NULL;
int error;
@@ -1224,7 +1224,7 @@
return error;
}

-static int __init check_sig(void)
+static int check_sig(void)
{
int error;

@@ -1254,7 +1254,7 @@
* already did that.
*/

-static int __init data_read(struct pbe *pblist)
+static int data_read(struct pbe *pblist)
{
struct pbe * p;
int error = 0;
@@ -1282,13 +1282,13 @@
return error;
}

-extern dev_t __init name_to_dev_t(const char *line);
+extern dev_t name_to_dev_t(const char *line);

/**
* read_pagedir - Read page backup list pages from swap
*/

-static int __init read_pagedir(struct pbe *pblist)
+static int read_pagedir(struct pbe *pblist)
{
struct pbe *pbpage, *p;
unsigned i = 0;
@@ -1322,10 +1322,9 @@
}


-static int __init read_suspend_image(void)
+static int check_suspend_image(void)
{
int error = 0;
- struct pbe *p;

if ((error = check_sig()))
return error;
@@ -1333,6 +1332,14 @@
if ((error = check_header()))
return error;

+ return 0;
+}
+
+static int read_suspend_image(void)
+{
+ int error = 0;
+ struct pbe *p;
+
if (!(p = alloc_pagedir(nr_copy_pages)))
return -ENOMEM;

@@ -1363,30 +1370,72 @@
}

/**
- * swsusp_read - Read saved image from swap.
+ * swsusp_check - Check for saved image in swap
*/

-int __init swsusp_read(void)
+int swsusp_check(void)
{
int error;

- if (!strlen(resume_file))
- return -ENOENT;
-
- resume_device = name_to_dev_t(resume_file);
- pr_debug("swsusp: Resume From Partition: %s\n", resume_file);
+ if (!swsusp_resume_device) {
+ if (!strlen(resume_file))
+ return -ENOENT;
+ swsusp_resume_device = name_to_dev_t(resume_file);
+ pr_debug("swsusp: Resume From Partition %s\n", resume_file);
+ } else {
+ pr_debug("swsusp: Resume From Partition %d:%d\n",
+ MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
+ }

- resume_bdev = open_by_devnum(resume_device, FMODE_READ);
+ resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
if (!IS_ERR(resume_bdev)) {
set_blocksize(resume_bdev, PAGE_SIZE);
- error = read_suspend_image();
- blkdev_put(resume_bdev);
+ error = check_suspend_image();
+ if (error)
+ blkdev_put(resume_bdev);
} else
error = PTR_ERR(resume_bdev);

if (!error)
- pr_debug("Reading resume file was successful\n");
+ pr_debug("swsusp: resume file found\n");
+ else
+ pr_debug("swsusp: Error %d check for resume file\n", error);
+ return error;
+}
+
+/**
+ * swsusp_read - Read saved image from swap.
+ */
+
+int swsusp_read(void)
+{
+ int error;
+
+ if (IS_ERR(resume_bdev)) {
+ pr_debug("swsusp: block device not initialised\n");
+ return PTR_ERR(resume_bdev);
+ }
+
+ error = read_suspend_image();
+ blkdev_put(resume_bdev);
+
+ if (!error)
+ pr_debug("swsusp: Reading resume file was successful\n");
else
pr_debug("swsusp: Error %d resuming\n", error);
return error;
}
+
+/**
+ * swsusp_close - close swap device.
+ */
+
+void swsusp_close(void)
+{
+ if (IS_ERR(resume_bdev)) {
+ pr_debug("swsusp: block device not initialised\n");
+ return;
+ }
+
+ blkdev_put(resume_bdev);
+}

--
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!
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