trivial: doc: hpfall: accept disk device to unload as argument

Allows users who use an IDE driver for their disk to use hpfall without
having to modify the source. By default /dev/sda is used.
Suggested by Christian Thaeter in http://lkml.org/lkml/2009/3/25/505.

While we're add it, improve error message if opening /dev/freefall fails.

Signed-off-by: Frans Pop <elendil@planet.nl>
Cc: Christian Thaeter <ct@pipapo.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Frans Pop 2009-07-25 21:00:12 +02:00 committed by Jiri Kosina
parent 2bace8b951
commit be3990b7ef

View file

@ -19,6 +19,32 @@
#include <sys/mman.h>
#include <sched.h>
char unload_heads_path[64];
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));
snprintf(unload_heads_path, sizeof(unload_heads_path),
"/sys/block/%s/device/unload_heads", devname);
return 0;
}
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;
}
void write_int(char *path, int i)
{
char buf[1024];
@ -42,7 +68,7 @@ void set_led(int on)
void protect(int seconds)
{
write_int("/sys/block/sda/device/unload_heads", seconds*1000);
write_int(unload_heads_path, seconds*1000);
}
int on_ac(void)
@ -61,14 +87,27 @@ void ignore_me(void)
set_led(0);
}
int main(int argc, char *argv[])
int main(int argc, char **argv)
{
int fd, ret;
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("open");
perror("/dev/freefall");
return EXIT_FAILURE;
}