commands/umount/umount.c

   1 /* umount - unmount a file system               Author: Andy Tanenbaum */
   2
   3 #include <minix/type.h>
   4 #include <sys/types.h>
   5 #include <sys/stat.h>
   6 #include <fcntl.h>
   7 #include <getopt.h>
   8 #include <errno.h>
   9 #include <limits.h>
  10 #include <minix/minlib.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <unistd.h>
  14 #include <sys/mount.h>
  15 #include <stdio.h>
  16
  17 int main(int argc, char **argv);
  18 int find_mtab_entry(char *name);
  19 void update_mtab(void);
  20 void usage(void);
  21
  22 static char device[PATH_MAX], mount_point[PATH_MAX], type[MNTNAMELEN],
  23                 flags[MNTFLAGLEN];
  24
  25 int main(argc, argv)
  26 int argc;
  27 char *argv[];
  28 {
  29   int found;
  30   int umount_flags = 0UL;
  31   int c;
  32   char *name;
  33
  34   while ((c = getopt (argc, argv, "e")) != -1)
  35   {
  36         switch (c) {
  37                 case 'e': umount_flags |= MS_EXISTING; break;
  38                 default: break;
  39         }
  40   }
  41
  42   if (argc - optind != 1) {
  43            usage();
  44   }
  45
  46   name = argv[optind];
  47
  48   found = find_mtab_entry(name);
  49
  50   if (minix_umount(name, umount_flags) < 0) {
  51         if (errno == EINVAL)
  52                 std_err("umount: Device not mounted\n");
  53         else if (errno == ENOTBLK)
  54                 std_err("umount: Not a mountpoint\n");
  55         else
  56                 perror("umount");
  57         exit(1);
  58   }
  59   if (found) {
  60         printf("%s unmounted from %s\n", device, mount_point);
  61   }
  62   return(0);
  63 }
  64
  65 int find_mtab_entry(name)
  66 char *name;
  67 {
  68 /* Find a matching mtab entry for 'name' which may be a special or a path,
  69  * and generate a new mtab file without this entry on the fly. Do not write
  70  * out the result yet. Return whether we found a matching entry.
  71  */
  72   char e_dev[PATH_MAX], e_mount_point[PATH_MAX], e_type[MNTNAMELEN],
  73         e_flags[MNTFLAGLEN];
  74   struct stat nstat, mstat;
  75   int n, found;
  76
  77   if (load_mtab("umount") < 0) return 0;
  78
  79   if (stat(name, &nstat) != 0) return 0;
  80
  81   found = 0;
  82   while (1) {
  83         n = get_mtab_entry(e_dev, e_mount_point, e_type, e_flags);
  84         if (n < 0) break;
  85         if (strcmp(name, e_dev) == 0 || (stat(e_mount_point, &mstat) == 0 &&
  86                 mstat.st_dev == nstat.st_dev && mstat.st_ino == nstat.st_ino))
  87         {
  88                 strlcpy(device, e_dev, PATH_MAX);
  89                 strlcpy(mount_point, e_mount_point, PATH_MAX);
  90                 strlcpy(type, e_type, MNTNAMELEN);
  91                 strlcpy(flags, e_flags, MNTFLAGLEN);
  92                 found = 1;
  93                 break;
  94         }
  95   }
  96
  97   return found;
  98 }
  99
 100 void usage()
 101 {
 102   std_err("Usage: umount [-e] name\n");
 103   exit(1);
 104 }