Merge tag 'nfs-for-5.2-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
[sfrench/cifs-2.6.git] / tools / laptop / freefall / freefall.c
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 Roh├ír <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 }