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Based on kernel version 3.13. Page generated on 2014-01-20 22:03 EST.

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