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-rw-r--r--Documentation/laptops/freefall.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/Documentation/laptops/freefall.c b/Documentation/laptops/freefall.c
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+/* 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, &param);
+ 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;
+}

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