minix/usr.sbin/diskctl/diskctl.c

   1 /* diskctl - control disk device driver parameters - by D.C. van Moolenbroek */
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <string.h>
   5 #include <sys/ioctl.h>
   6 #include <unistd.h>
   7 #include <fcntl.h>
   8
   9 static void __dead
  10 usage(void)
  11 {
  12         fprintf(stderr,
  13             "usage: %s <device> <command> [args]\n"
  14             "\n"
  15             "supported commands:\n"
  16             "  getwcache           return write cache status\n"
  17             "  setwcache [on|off]  set write cache status\n"
  18             "  flush               flush write cache\n",
  19             getprogname());
  20
  21         exit(EXIT_FAILURE);
  22 }
  23
  24 static int
  25 open_dev(const char * dev, int flags)
  26 {
  27         int fd;
  28
  29         fd = open(dev, flags);
  30
  31         if (fd < 0) {
  32                 perror("open");
  33
  34                 exit(EXIT_FAILURE);
  35         }
  36
  37         return fd;
  38 }
  39
  40 int
  41 main(int argc, char ** argv)
  42 {
  43         int fd, val;
  44
  45         setprogname(argv[0]);
  46
  47         if (argc < 3) usage();
  48
  49         if (!strcasecmp(argv[2], "getwcache")) {
  50                 if (argc != 3) usage();
  51
  52                 fd = open_dev(argv[1], O_RDONLY);
  53
  54                 if (ioctl(fd, DIOCGETWC, &val) != 0) {
  55                         perror("ioctl");
  56
  57                         return EXIT_FAILURE;
  58                 }
  59
  60                 close(fd);
  61
  62                 printf("write cache is %s\n", val ? "on" : "off");
  63
  64         } else if (!strcasecmp(argv[2], "setwcache")) {
  65                 if (argc != 4) usage();
  66
  67                 if (!strcasecmp(argv[3], "on"))
  68                         val = 1;
  69                 else if (!strcasecmp(argv[3], "off"))
  70                         val = 0;
  71                 else
  72                         usage();
  73
  74                 fd = open_dev(argv[1], O_WRONLY);
  75
  76                 if (ioctl(fd, DIOCSETWC, &val) != 0) {
  77                         perror("ioctl");
  78
  79                         return EXIT_FAILURE;
  80                 }
  81
  82                 close(fd);
  83
  84                 printf("write cache %sabled\n", val ? "en" : "dis");
  85
  86         } else if (!strcasecmp(argv[2], "flush")) {
  87                 if (argc != 3) usage();
  88
  89                 fd = open_dev(argv[1], O_WRONLY);
  90
  91                 if (ioctl(fd, DIOCFLUSH, NULL) != 0) {
  92                         perror("ioctl");
  93
  94                         return EXIT_FAILURE;
  95                 }
  96
  97                 close(fd);
  98
  99                 printf("write cache flushed\n");
 100
 101         } else
 102                 usage();
 103
 104         return EXIT_SUCCESS;
 105 }