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Diffstat (limited to 'Documentation/laptops/freefall.c')
| -rw-r--r-- | Documentation/laptops/freefall.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/Documentation/laptops/freefall.c b/Documentation/laptops/freefall.c new file mode 100644 index 00000000000..aab2ff09e86 --- /dev/null +++ b/Documentation/laptops/freefall.c @@ -0,0 +1,177 @@ +/* Disk protection for HP/DELL machines. + * + * Copyright 2008 Eric Piel + * Copyright 2009 Pavel Machek <pavel@ucw.cz> + * Copyright 2012 Sonal Santan + * Copyright 2014 Pali Rohár <pali.rohar@gmail.com> + * + * GPLv2. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <string.h> +#include <stdint.h> +#include <errno.h> +#include <signal.h> +#include <sys/mman.h> +#include <sched.h> +#include <syslog.h> + +static int noled; +static char unload_heads_path[64]; +static char device_path[32]; +static const char app_name[] = "FREE FALL"; + +static int set_unload_heads_path(char *device) +{ + char devname[64]; + + if (strlen(device) <= 5 || strncmp(device, "/dev/", 5) != 0) + return -EINVAL; + strncpy(devname, device + 5, sizeof(devname) - 1); + strncpy(device_path, device, sizeof(device_path) - 1); + + snprintf(unload_heads_path, sizeof(unload_heads_path) - 1, + "/sys/block/%s/device/unload_heads", devname); + return 0; +} + +static int valid_disk(void) +{ + int fd = open(unload_heads_path, O_RDONLY); + + if (fd < 0) { + perror(unload_heads_path); + return 0; + } + + close(fd); + return 1; +} + +static void write_int(char *path, int i) +{ + char buf[1024]; + int fd = open(path, O_RDWR); + + if (fd < 0) { + perror("open"); + exit(1); + } + + sprintf(buf, "%d", i); + + if (write(fd, buf, strlen(buf)) != strlen(buf)) { + perror("write"); + exit(1); + } + + close(fd); +} + +static void set_led(int on) +{ + if (noled) + return; + write_int("/sys/class/leds/hp::hddprotect/brightness", on); +} + +static void protect(int seconds) +{ + const char *str = (seconds == 0) ? "Unparked" : "Parked"; + + write_int(unload_heads_path, seconds*1000); + syslog(LOG_INFO, "%s %s disk head\n", str, device_path); +} + +static int on_ac(void) +{ + /* /sys/class/power_supply/AC0/online */ + return 1; +} + +static int lid_open(void) +{ + /* /proc/acpi/button/lid/LID/state */ + return 1; +} + +static void ignore_me(int signum) +{ + protect(0); + set_led(0); +} + +int main(int argc, char **argv) +{ + int fd, ret; + struct stat st; + struct sched_param param; + + if (argc == 1) + ret = set_unload_heads_path("/dev/sda"); + else if (argc == 2) + ret = set_unload_heads_path(argv[1]); + else + ret = -EINVAL; + + if (ret || !valid_disk()) { + fprintf(stderr, "usage: %s <device> (default: /dev/sda)\n", + argv[0]); + exit(1); + } + + fd = open("/dev/freefall", O_RDONLY); + if (fd < 0) { + perror("/dev/freefall"); + return EXIT_FAILURE; + } + + if (stat("/sys/class/leds/hp::hddprotect/brightness", &st)) + noled = 1; + + if (daemon(0, 0) != 0) { + perror("daemon"); + return EXIT_FAILURE; + } + + openlog(app_name, LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1); + + param.sched_priority = sched_get_priority_max(SCHED_FIFO); + sched_setscheduler(0, SCHED_FIFO, ¶m); + mlockall(MCL_CURRENT|MCL_FUTURE); + + signal(SIGALRM, ignore_me); + + for (;;) { + unsigned char count; + + ret = read(fd, &count, sizeof(count)); + alarm(0); + if ((ret == -1) && (errno == EINTR)) { + /* Alarm expired, time to unpark the heads */ + continue; + } + + if (ret != sizeof(count)) { + perror("read"); + break; + } + + protect(21); + set_led(1); + if (1 || on_ac() || lid_open()) + alarm(2); + else + alarm(20); + } + + closelog(); + close(fd); + return EXIT_SUCCESS; +} |