kinit/resume/resumelib.c

/*
 * Handle resume from suspend-to-disk
 */

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>

#include "kinit.h"
#include "do_mounts.h"
#include "resume.h"

#ifndef CONFIG_PM_STD_PARTITION
# define CONFIG_PM_STD_PARTITION ""
#endif

int do_resume(int argc, char *argv[])
{
	const char *resume_file = CONFIG_PM_STD_PARTITION;
	const char *resume_arg;
	unsigned long long resume_offset;

	resume_arg = get_arg(argc, argv, "resume=");
	resume_file = resume_arg ? resume_arg : resume_file;
	/* No resume device specified */
	if (!resume_file[0])
		return 0;

	resume_arg = get_arg(argc, argv, "resume_offset=");
	resume_offset = resume_arg ? strtoull(resume_arg, NULL, 0) : 0ULL;

	/* Fix: we either should consider reverting the device back to
	   ordinary swap, or (better) put that code into swapon */
	/* Noresume requested */
	if (get_flag(argc, argv, "noresume"))
		return 0;
	return resume(resume_file, resume_offset);
}

int resume(const char *resume_file, unsigned long long resume_offset)
{
	dev_t resume_device;
	int powerfd = -1;
	char device_string[64];
	int len;

	resume_device = name_to_dev_t(resume_file);

	if (major(resume_device) == 0) {
		fprintf(stderr, "Invalid resume device: %s\n", resume_file);
		goto failure;
	}

	if ((powerfd = open("/sys/power/resume", O_WRONLY)) < 0)
		goto fail_r;

	len = snprintf(device_string, sizeof device_string,
		       "%u:%u:%llu",
		       major(resume_device), minor(resume_device),
		       resume_offset);

	/* This should never happen */
	if (len >= sizeof device_string)
		goto fail_r;

	dprintf("kinit: trying to resume from %s\n", resume_file);

	if (write(powerfd, device_string, len) != len)
		goto fail_r;

	/* Okay, what are we still doing alive... */
failure:
	if (powerfd >= 0)
		close(powerfd);
	dprintf("kinit: No resume image, doing normal boot...\n");
	return -1;

fail_r:
	fprintf(stderr, "Cannot write /sys/power/resume "
			"(no software suspend kernel support?)\n");
	goto failure;
}
1	/*
2	* Handle resume from suspend-to-disk
3	*/
4
5	#include <fcntl.h>
6	#include <stdio.h>
7	#include <stdlib.h>
8	#include <string.h>
9	#include <limits.h>
10	#include <sys/stat.h>
11	#include <sys/sysmacros.h>
12
13	#include "kinit.h"
14	#include "do_mounts.h"
15	#include "resume.h"
16
17	#ifndef CONFIG_PM_STD_PARTITION
18	# define CONFIG_PM_STD_PARTITION ""
19	#endif
20
21	int do_resume(int argc, char *argv[])
22	{
23	const char *resume_file = CONFIG_PM_STD_PARTITION;
24	const char *resume_arg;
25	unsigned long long resume_offset;
26
27	resume_arg = get_arg(argc, argv, "resume=");
28	resume_file = resume_arg ? resume_arg : resume_file;
29	/* No resume device specified */
30	if (!resume_file[0])
31	return 0;
32
33	resume_arg = get_arg(argc, argv, "resume_offset=");
34	resume_offset = resume_arg ? strtoull(resume_arg, NULL, 0) : 0ULL;
35
36	/* Fix: we either should consider reverting the device back to
37	ordinary swap, or (better) put that code into swapon */
38	/* Noresume requested */
39	if (get_flag(argc, argv, "noresume"))
40	return 0;
41	return resume(resume_file, resume_offset);
42	}
43
44	int resume(const char *resume_file, unsigned long long resume_offset)
45	{
46	dev_t resume_device;
47	int powerfd = -1;
48	char device_string[64];
49	int len;
50
51	resume_device = name_to_dev_t(resume_file);
52
53	if (major(resume_device) == 0) {
54	fprintf(stderr, "Invalid resume device: %s\n", resume_file);
55	goto failure;
56	}
57
58	if ((powerfd = open("/sys/power/resume", O_WRONLY)) < 0)
59	goto fail_r;
60
61	len = snprintf(device_string, sizeof device_string,
62	"%u:%u:%llu",
63	major(resume_device), minor(resume_device),
64	resume_offset);
65
66	/* This should never happen */
67	if (len >= sizeof device_string)
68	goto fail_r;
69
70	dprintf("kinit: trying to resume from %s\n", resume_file);
71
72	if (write(powerfd, device_string, len) != len)
73	goto fail_r;
74
75	/* Okay, what are we still doing alive... */
76	failure:
77	if (powerfd >= 0)
78	close(powerfd);
79	dprintf("kinit: No resume image, doing normal boot...\n");
80	return -1;
81
82	fail_r:
83	fprintf(stderr, "Cannot write /sys/power/resume "
84	"(no software suspend kernel support?)\n");
85	goto failure;
86	}