kinit/resume/resumelib.c

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

#include <errno.h>
#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 <errno.h>
6	#include <fcntl.h>
7	#include <stdio.h>
8	#include <stdlib.h>
9	#include <string.h>
10	#include <limits.h>
11	#include <sys/stat.h>
12	#include <sys/sysmacros.h>
13
14	#include "kinit.h"
15	#include "do_mounts.h"
16	#include "resume.h"
17
18	#ifndef CONFIG_PM_STD_PARTITION
19	# define CONFIG_PM_STD_PARTITION ""
20	#endif
21
22	int do_resume(int argc, char *argv[])
23	{
24	const char *resume_file = CONFIG_PM_STD_PARTITION;
25	const char *resume_arg;
26	unsigned long long resume_offset;
27
28	resume_arg = get_arg(argc, argv, "resume=");
29	resume_file = resume_arg ? resume_arg : resume_file;
30	/* No resume device specified */
31	if (!resume_file[0])
32	return 0;
33
34	resume_arg = get_arg(argc, argv, "resume_offset=");
35	resume_offset = resume_arg ? strtoull(resume_arg, NULL, 0) : 0ULL;
36
37	/* Fix: we either should consider reverting the device back to
38	ordinary swap, or (better) put that code into swapon */
39	/* Noresume requested */
40	if (get_flag(argc, argv, "noresume"))
41	return 0;
42	return resume(resume_file, resume_offset);
43	}
44
45	int resume(const char *resume_file, unsigned long long resume_offset)
46	{
47	dev_t resume_device;
48	int powerfd = -1;
49	char device_string[64];
50	int len;
51
52	resume_device = name_to_dev_t(resume_file);
53
54	if (major(resume_device) == 0) {
55	fprintf(stderr, "Invalid resume device: %s\n", resume_file);
56	goto failure;
57	}
58
59	if ((powerfd = open("/sys/power/resume", O_WRONLY)) < 0)
60	goto fail_r;
61
62	len = snprintf(device_string, sizeof device_string,
63	"%u:%u:%llu",
64	major(resume_device), minor(resume_device),
65	resume_offset);
66
67	/* This should never happen */
68	if (len >= sizeof device_string)
69	goto fail_r;
70
71	dprintf("kinit: trying to resume from %s\n", resume_file);
72
73	if (write(powerfd, device_string, len) != len)
74	goto fail_r;
75
76	/* Okay, what are we still doing alive... */
77	failure:
78	if (powerfd >= 0)
79	close(powerfd);
80	dprintf("kinit: No resume image, doing normal boot...\n");
81	return -1;
82
83	fail_r:
84	fprintf(stderr, "Cannot write /sys/power/resume "
85	"(no software suspend kernel support?)\n");
86	goto failure;
87	}