e2fsprogs/misc/fstype.c
Theodore Ts'o 5599c2fa87 Changed fsck to support filesystems types in /etc/fstab of the form
"ext3,ext2", etc.

Added support for only searching for a specified list of filesystems.
	Also add support for identifying reiserfs filesystems.
2002-02-03 00:08:52 -05:00

111 lines
2.5 KiB
C

/*
* fstype.c
*
* Copyright (C) 2001 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Public
* License.
* %End-Header%
*/
#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <fcntl.h>
#include <sys/types.h>
#include "fsck.h"
struct fs_magic {
const char *fs_name;
int offset;
int len;
const char *magic;
};
#define REISERFS_SUPER_MAGIC_STRING "ReIsErFs"
#define REISER2FS_SUPER_MAGIC_STRING "ReIsEr2Fs"
#define REISERFS_DISK_OFFSET_IN_BYTES ((64 * 1024) + 52)
/* the spot for the super in versions 3.5 - 3.5.10 (inclusive) */
#define REISERFS_OLD_DISK_OFFSET_IN_BYTES ((8 * 1024) + 52)
struct fs_magic type_array[] = {
{ "ext2", 1024+56, 2, "\123\357" },
{ "ext3", 1024+56, 2, "\123\357" },
{ "reiserfs", REISERFS_DISK_OFFSET_IN_BYTES, 9,
REISER2FS_SUPER_MAGIC_STRING },
{ "reiserfs", REISERFS_DISK_OFFSET_IN_BYTES, 8,
REISERFS_SUPER_MAGIC_STRING },
{ "reiserfs", REISERFS_OLD_DISK_OFFSET_IN_BYTES, 9,
REISER2FS_SUPER_MAGIC_STRING },
{ "reiserfs", REISERFS_OLD_DISK_OFFSET_IN_BYTES, 8,
REISERFS_SUPER_MAGIC_STRING },
{ "minix", 1040, 2, "\177\023" },
{ "minix", 1040, 2, "\217\023" },
{ "minix", 1040, 2, "\150\044" },
{ "minix", 1040, 2, "\170\044" },
{ "xfs", 0, 4, "XFSB" },
{ 0, 0, 0, 0 }
};
const char *identify_fs(const char *fs_name, const char *fs_types)
{
char buf[73728], *s;
const char *t;
struct fs_magic *p;
int fd;
fd = open(fs_name, O_RDONLY);
if (fd < 0)
return NULL;
if (lseek(fd, 0, SEEK_SET) < 0)
return NULL;
if (read(fd, buf, sizeof(buf)) != sizeof(buf))
return NULL;
close(fd);
if (!fs_types || !strcmp(fs_types, "auto")) {
for (p = type_array; p->fs_name; p++) {
if (memcmp(p->magic, buf+p->offset, p->len) == 0)
return p->fs_name;
}
} else {
s = string_copy(fs_types);
for (t = strtok(s, ","); t; t = strtok(NULL, ",")) {
for (p = type_array; p->fs_name; p++) {
if (strcmp(p->fs_name, t))
continue;
if (memcmp(p->magic, buf+p->offset,
p->len) == 0) {
free(s);
return p->fs_name;
}
}
}
free(s);
}
return NULL;
}
#ifdef TEST_PROGRAM
int main(int argc, char **argv)
{
const char *type;
if (argc < 2 || argc > 3) {
fprintf(stderr, "Usage: %s [type list] device\n", argv[0]);
exit(1);
}
if (argc == 2) {
type = identify_fs(argv[1], NULL);
printf("%s is a %s filesystem\n", argv[1], type);
} else {
type = identify_fs(argv[2],argv[1]);
printf("%s is a %s filesystem\n", argv[2], type);
}
return (0);
}
#endif