minix/commands/umount/umount.c

131 lines
2.8 KiB
C

/* umount - unmount a file system Author: Andy Tanenbaum */
#define _MINIX 1 /* for proto of the non-POSIX umount() */
#define _POSIX_SOURCE 1 /* for PATH_MAX from limits.h */
#include <minix/type.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <getopt.h>
#include <errno.h>
#include <limits.h>
#include <minix/minlib.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mount.h>
#include <stdio.h>
_PROTOTYPE(int main, (int argc, char **argv));
_PROTOTYPE(int find_mtab_entry, (char *name));
_PROTOTYPE(void update_mtab, (void));
_PROTOTYPE(void usage, (void));
static char device[PATH_MAX+1], mountpoint[PATH_MAX+1], vs[10], rw[10];
int main(argc, argv)
int argc;
char *argv[];
{
int found;
int flags = 0UL;
int i;
char c;
char *name;
while ((c = getopt (argc, argv, "e")) != -1)
{
switch (c) {
case 'e': flags |= MS_EXISTING; break;
default: break;
}
}
if (argc - optind != 1) {
usage();
}
name = argv[optind];
found = find_mtab_entry(name);
if (umount2(name, flags) < 0) {
if (errno == EINVAL)
std_err("umount: Device not mounted\n");
else if (errno == ENOTBLK)
std_err("umount: Not a mountpoint\n");
else
perror("umount");
exit(1);
}
if (found) {
printf("%s unmounted from %s\n", device, mountpoint);
update_mtab();
}
else printf("%s unmounted (mtab not updated)\n", name);
return(0);
}
int find_mtab_entry(name)
char *name;
{
/* Find a matching mtab entry for 'name' which may be a special or a path,
* and generate a new mtab file without this entry on the fly. Do not write
* out the result yet. Return whether we found a matching entry.
*/
char special[PATH_MAX+1], mounted_on[PATH_MAX+1], version[10], rw_flag[10];
struct stat nstat, mstat;
int n, found;
if (load_mtab("umount") < 0) return 0;
if (stat(name, &nstat) != 0) return 0;
found = 0;
while (1) {
n = get_mtab_entry(special, mounted_on, version, rw_flag);
if (n < 0) break;
if (strcmp(name, special) == 0 || (stat(mounted_on, &mstat) == 0 &&
mstat.st_dev == nstat.st_dev && mstat.st_ino == nstat.st_ino))
{
/* If we found an earlier match, keep that one. Mountpoints
* may be stacked on top of each other, and unmounting should
* take place in the reverse order of mounting.
*/
if (found) {
(void) put_mtab_entry(device, mountpoint, vs, rw);
}
strcpy(device, special);
strcpy(mountpoint, mounted_on);
strcpy(vs, version);
strcpy(rw, rw_flag);
found = 1;
continue;
}
(void) put_mtab_entry(special, mounted_on, version, rw_flag);
}
return found;
}
void update_mtab()
{
/* Write out the new mtab file. */
int n;
n = rewrite_mtab("umount");
if (n < 0) {
std_err("/etc/mtab not updated.\n");
exit(1);
}
}
void usage()
{
std_err("Usage: umount [-e] name\n");
exit(1);
}