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Based on kernel version 4.1. Page generated on 2015-06-28 12:13 EST.

1	/* Disk protection for HP/DELL machines.
2	 *
3	 * Copyright 2008 Eric Piel
4	 * Copyright 2009 Pavel Machek <pavel@ucw.cz>
5	 * Copyright 2012 Sonal Santan
6	 * Copyright 2014 Pali Rohár <pali.rohar@gmail.com>
7	 *
8	 * GPLv2.
9	 */
10	
11	#include <stdio.h>
12	#include <stdlib.h>
13	#include <unistd.h>
14	#include <fcntl.h>
15	#include <sys/stat.h>
16	#include <sys/types.h>
17	#include <string.h>
18	#include <stdint.h>
19	#include <errno.h>
20	#include <signal.h>
21	#include <sys/mman.h>
22	#include <sched.h>
23	#include <syslog.h>
24	
25	static int noled;
26	static char unload_heads_path[64];
27	static char device_path[32];
28	static const char app_name[] = "FREE FALL";
29	
30	static int set_unload_heads_path(char *device)
31	{
32		if (strlen(device) <= 5 || strncmp(device, "/dev/", 5) != 0)
33			return -EINVAL;
34		strncpy(device_path, device, sizeof(device_path) - 1);
35	
36		snprintf(unload_heads_path, sizeof(unload_heads_path) - 1,
37					"/sys/block/%s/device/unload_heads", device+5);
38		return 0;
39	}
40	
41	static int valid_disk(void)
42	{
43		int fd = open(unload_heads_path, O_RDONLY);
44	
45		if (fd < 0) {
46			perror(unload_heads_path);
47			return 0;
48		}
49	
50		close(fd);
51		return 1;
52	}
53	
54	static void write_int(char *path, int i)
55	{
56		char buf[1024];
57		int fd = open(path, O_RDWR);
58	
59		if (fd < 0) {
60			perror("open");
61			exit(1);
62		}
63	
64		sprintf(buf, "%d", i);
65	
66		if (write(fd, buf, strlen(buf)) != strlen(buf)) {
67			perror("write");
68			exit(1);
69		}
70	
71		close(fd);
72	}
73	
74	static void set_led(int on)
75	{
76		if (noled)
77			return;
78		write_int("/sys/class/leds/hp::hddprotect/brightness", on);
79	}
80	
81	static void protect(int seconds)
82	{
83		const char *str = (seconds == 0) ? "Unparked" : "Parked";
84	
85		write_int(unload_heads_path, seconds*1000);
86		syslog(LOG_INFO, "%s %s disk head\n", str, device_path);
87	}
88	
89	static int on_ac(void)
90	{
91		/* /sys/class/power_supply/AC0/online */
92		return 1;
93	}
94	
95	static int lid_open(void)
96	{
97		/* /proc/acpi/button/lid/LID/state */
98		return 1;
99	}
100	
101	static void ignore_me(int signum)
102	{
103		protect(0);
104		set_led(0);
105	}
106	
107	int main(int argc, char **argv)
108	{
109		int fd, ret;
110		struct stat st;
111		struct sched_param param;
112	
113		if (argc == 1)
114			ret = set_unload_heads_path("/dev/sda");
115		else if (argc == 2)
116			ret = set_unload_heads_path(argv[1]);
117		else
118			ret = -EINVAL;
119	
120		if (ret || !valid_disk()) {
121			fprintf(stderr, "usage: %s <device> (default: /dev/sda)\n",
122					argv[0]);
123			exit(1);
124		}
125	
126		fd = open("/dev/freefall", O_RDONLY);
127		if (fd < 0) {
128			perror("/dev/freefall");
129			return EXIT_FAILURE;
130		}
131	
132		if (stat("/sys/class/leds/hp::hddprotect/brightness", &st))
133			noled = 1;
134	
135		if (daemon(0, 0) != 0) {
136			perror("daemon");
137			return EXIT_FAILURE;
138		}
139	
140		openlog(app_name, LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
141	
142		param.sched_priority = sched_get_priority_max(SCHED_FIFO);
143		sched_setscheduler(0, SCHED_FIFO, &param);
144		mlockall(MCL_CURRENT|MCL_FUTURE);
145	
146		signal(SIGALRM, ignore_me);
147	
148		for (;;) {
149			unsigned char count;
150	
151			ret = read(fd, &count, sizeof(count));
152			alarm(0);
153			if ((ret == -1) && (errno == EINTR)) {
154				/* Alarm expired, time to unpark the heads */
155				continue;
156			}
157	
158			if (ret != sizeof(count)) {
159				perror("read");
160				break;
161			}
162	
163			protect(21);
164			set_led(1);
165			if (1 || on_ac() || lid_open())
166				alarm(2);
167			else
168				alarm(20);
169		}
170	
171		closelog();
172		close(fd);
173		return EXIT_SUCCESS;
174	}
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