/*
* hd-idle.c - external disk idle daemon
*
* Copyright (c) 2007 Christian Mueller.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* hd-idle is a utility program for spinning-down external disks after a period
* of idle time. Since most external IDE disk enclosures don't support setting
* the IDE idle timer, a program like hd-idle is required to spin down idle
* disks automatically.
*
* A word of caution: hard disks don't like spinning-up too often. Laptop disks
* are more robust in this respect than desktop disks but if you set your disks
* to spin down after a few seconds you may damage the disk over time due to the
* stress the spin-up causes on the spindle motor and bearings. It seems that
* manufacturers recommend a minimum idle time of 3-5 minutes, the default in
* hd-idle is 10 minutes.
*
* Please note that hd-idle can spin down any disk accessible via the SCSI
* layer (USB, IEEE1394, ...) but it will NOT work with real SCSI disks because
* they don't spin up automatically. Thus it's not called scsi-idle and I don't
* recommend using it on a real SCSI system unless you have a kernel patch that
* automatically starts the SCSI disks after receiving a sense buffer indicating
* the disk has been stopped. Without such a patch, real SCSI disks won't start
* again and you can as well pull the plug.
*
* You have been warned...
*
* CVS Change Log:
* ---------------
*
* $Log: hd-idle.c,v $
* Revision 1.2 2007/04/23 22:14:27 cjmueller
* Bug fixes
* - Comment changes; no functionality changes...
*
* Revision 1.1.1.1 2007/04/23 21:49:43 cjmueller
* initial import into CVS
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <ctype.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <scsi/sg.h>
#define STAT_FILE "/proc/diskstats"
#define dprintf if (debug) printf
#if 1
/* AMV/WK Patch 20090520: Skip removable devices */
#define SYSFS_PATH "/sys/"
#endif
/* typedefs and structures */
typedef struct DISKSTATS {
struct DISKSTATS *next;
char name[50];
time_t last_io;
time_t spindown;
time_t spinup;
unsigned int spun_down : 1;
unsigned int reads;
unsigned int writes;
} DISKSTATS;
/* function prototypes */
static void daemonize (void);
static DISKSTATS *get_diskstats (const char *name);
static void spindown_disk (const char *name);
static void log_spinup (DISKSTATS *ds);
/* global/static variables */
DISKSTATS *ds_root;
const char *logfile = "/dev/null";
int debug;
/* main function */
int main(int argc, char *argv[])
{
int have_logfile = 0;
int idle_time = 600;
int sleep_time;
int opt;
if(setpriority(PRIO_PROCESS, 0, 19) < 0 ) {
fprintf(stderr, "%s: setpriority() failed\n", argv[0]);
}
/* process command line options */
while ((opt = getopt(argc, argv, "t:i:l:dh")) != -1) {
switch (opt) {
case 't':
/* just spin-down the specified disk and exit */
spindown_disk(optarg);
return(0);
case 'i':
idle_time = atoi(optarg);
break;
case 'l':
logfile = optarg;
have_logfile = 1;
break;
case 'd':
debug = 1;
break;
case 'h':
printf("usage: hd-idle [-t <disk>] [-i <idle_time>] [-l <logfile>] [-d] [-h]\n");
return(0);
case ':':
fprintf(stderr, "error: option -%c requires an argument\n", optopt);
return(1);
case '?':
fprintf(stderr, "error: unknown option -%c\n", optopt);
return(1);
}
}
/* set sleep interval */
if ((sleep_time = idle_time / 10) == 0) {
sleep_time = 1;
}
/* daemonize unless we're running in debug mode */
if (!debug) {
daemonize();
}
/* main loop: probe for idle disks and stop them */
for (;;) {
DISKSTATS tmp;
FILE *fp;
char buf[200];
if ((fp = fopen(STAT_FILE, "r")) == NULL) {
perror(STAT_FILE);
return(2);
}
memset(&tmp, 0x00, sizeof(tmp));
while (fgets(buf, sizeof(buf), fp) != NULL) {
/* 49 = sizeof(tmp.name) - 1 */
if (sscanf(buf, "%*d %*d %49s %*u %*u %u %*u %*u %*u %u %*u %*u %*u %*u",
tmp.name, &tmp.reads, &tmp.writes) == 3) {
DISKSTATS *ds;
time_t now = time(NULL);
/* make sure this is a SCSI disk (sd[a-z]) */
if (tmp.name[0] != 's' ||
tmp.name[1] != 'd' ||
!isalpha(tmp.name[2]) ||
tmp.name[3] != '\0') {
continue;
}
/* get previous statistics for this disk */
ds = get_diskstats(tmp.name);
if (ds == NULL) {
/* new disk; just add it to the linked list */
ds = malloc(sizeof(*ds));
memcpy(ds, &tmp, sizeof(*ds));
ds->last_io = time(NULL);
ds->spinup = ds->last_io;
ds->next = ds_root;
ds_root = ds;
} else if (ds->reads == tmp.reads && ds->writes == tmp.writes) {
if (!ds->spun_down) {
/* no activity on this disk and still running */
if (now - ds->last_io > idle_time) {
spindown_disk(ds->name);
ds->spindown = time(NULL);
ds->spun_down = 1;
}
}
} else {
/* disk had some activity */
if (ds->spun_down) {
/* disk was spun down, thus it has just spun up */
if (have_logfile) {
log_spinup(ds);
}
ds->spinup = time(NULL);
}
ds->reads = tmp.reads;
ds->writes = tmp.writes;
ds->last_io = time(NULL);
ds->spun_down = 0;
}
}
}
fclose(fp);
sleep(sleep_time);
}
return(0);
}
/* become a daemon */
static void daemonize(void)
{
int maxfd;
int i;
/* fork #1: exit parent process and continue in the background */
if ((i = fork()) < 0) {
perror("couldn't fork");
exit(2);
} else if (i > 0) {
_exit(0);
}
/* fork #2: detach from terminal and fork again so we can never regain
* access to the terminal */
setsid();
if ((i = fork()) < 0) {
perror("couldn't fork #2");
exit(2);
} else if (i > 0) {
_exit(0);
}
/* change to root directory and close file descriptors */
chdir("/");
maxfd = getdtablesize();
for (i = 0; i < maxfd; i++) {
/* close(i); */
}
/* use /dev/null for stdin, stdout and stderr */
open("/dev/null", O_RDONLY);
open("/dev/null", O_WRONLY);
open("/dev/null", O_WRONLY);
}
/* get DISKSTATS entry by name of disk */
static DISKSTATS *get_diskstats(const char *name)
{
DISKSTATS *ds;
for (ds = ds_root; ds != NULL; ds = ds->next) {
if (!strcmp(ds->name, name)) {
return(ds);
}
}
return(NULL);
}
/* spin-down a disk */
static void spindown_disk(const char *name)
{
struct sg_io_hdr io_hdr;
unsigned char sense_buf[255];
char dev_name[100];
int fd;
#if 1
/* AVM/WK Patch 20090520: Skip removable devices */
{
FILE *rfp;
char sRemovableFile[200];
char cremovable = '1';
snprintf(sRemovableFile, sizeof(sRemovableFile), SYSFS_PATH "/block/%s/removable", name);
if ((rfp = fopen(sRemovableFile, "r")) == NULL) {
perror(sRemovableFile);
fprintf(stderr, "removable??? : skipping disk %s in hd-idle spindown!\n", name);
return;
}
cremovable = fgetc(rfp);
fclose(rfp);
if (cremovable != '0') {
fprintf(stderr, "hd-idle: skipping removable disk %s\n", name);
return;
}
}
#endif
#if 1
/* AVM/VGJ Patch 20171016: Skip suspended devices */
{
FILE *rfp;
char sSuspendedFile[200];
char csuspended = 0;
snprintf(sSuspendedFile, sizeof(sSuspendedFile), SYSFS_PATH "/block/%s/device/../../../../avm_usb_suspend_status", name);
rfp = fopen(sSuspendedFile, "r");
if (rfp == NULL) {
snprintf(sSuspendedFile, sizeof(sSuspendedFile), SYSFS_PATH "/block/%s/device/../../../../power/runtime_status", name);
rfp = fopen(sSuspendedFile, "r");
}
if (rfp != NULL) {
csuspended = fgetc(rfp);
fclose(rfp);
if (csuspended == 's') {
fprintf(stderr, "hd-idle: skipping suspended disk %s\n", name);
return;
}
}
}
#endif
/* fabricate SCSI IO request */
memset(&io_hdr, 0x00, sizeof(io_hdr));
io_hdr.interface_id = 'S';
io_hdr.dxfer_direction = SG_DXFER_NONE;
/* SCSI stop unit command */
io_hdr.cmdp = (unsigned char *) "\x1b\x00\x00\x00\x00\x00";
io_hdr.cmd_len = 6;
io_hdr.sbp = sense_buf;
io_hdr.mx_sb_len = (unsigned char) sizeof(sense_buf);
/* open disk device (kernel 2.4 will probably need "sg" names here) */
snprintf(dev_name, sizeof(dev_name), "/dev/%s", name);
if ((fd = open(dev_name, O_RDONLY)) < 0) {
perror(dev_name);
return;
}
/* execute SCSI request */
if (ioctl(fd, SG_IO, &io_hdr) < 0) {
char buf[100];
snprintf(buf, sizeof(buf), "ioctl on %s:", name);
perror(buf);
} else if (io_hdr.masked_status != 0) {
fprintf(stderr, "error: SCSI command failed with status 0x%02x\n",
io_hdr.masked_status);
}
close(fd);
}
/* write a spin-up event message to the log file */
static void log_spinup(DISKSTATS *ds)
{
FILE *fp;
if ((fp = fopen(logfile, "a")) != NULL) {
/* Print statistics to logfile
*
* Note: This doesn't work too well if there are multiple disks
* because the I/O we're dealing with might be on another
* disk so we effectively wake up the disk the log file is
* stored on as well. Then again the logfile is a debugging
* option, so what...
*/
time_t now = time(NULL);
char tstr[20];
char dstr[20];
strftime(dstr, sizeof(dstr), "%Y-%m-%d", localtime(&now));
strftime(tstr, sizeof(tstr), "%H:%M:%S", localtime(&now));
fprintf(fp,
"date: %s, time: %s, disk: %s, running: %ld, stopped: %ld\n",
dstr, tstr, ds->name,
(long) ds->spindown - (long) ds->spinup,
(long) time(NULL) - (long) ds->spindown);
/* Sync to make sure writing to the logfile won't cause another
* spinup in 30 seconds (or whatever bdflush uses as flush interval).
* Since there's already some I/O which caused the spin-up and we don't
* want to cause even more I/O, wait some time before doing this.
*/
fclose(fp);
sleep(3);
sync();
}
}