LXR busybox/e2fsprogs/old_e2fsprogs/ext2fs/check

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * check_desc.c --- Check the group descriptors of an ext2 filesystem
   4 *
   5 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
   6 *
   7 * %Begin-Header%
   8 * This file may be redistributed under the terms of the GNU Public
   9 * License.
  10 * %End-Header%
  11 */
  12
  13#include <stdio.h>
  14#include <string.h>
  15#if HAVE_UNISTD_H
  16#include <unistd.h>
  17#endif
  18#include <fcntl.h>
  19#include <time.h>
  20#if HAVE_SYS_STAT_H
  21#include <sys/stat.h>
  22#endif
  23#if HAVE_SYS_TYPES_H
  24#include <sys/types.h>
  25#endif
  26
  27#include "ext2_fs.h"
  28#include "ext2fs.h"
  29
  30/*
  31 * This routine sanity checks the group descriptors
  32 */
  33errcode_t ext2fs_check_desc(ext2_filsys fs)
  34{
  35        dgrp_t i;
  36        blk_t block = fs->super->s_first_data_block;
  37        blk_t next;
  38
  39        EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  40
  41        for (i = 0; i < fs->group_desc_count; i++) {
  42                next = block + fs->super->s_blocks_per_group;
  43                /*
  44                 * Check to make sure block bitmap for group is
  45                 * located within the group.
  46                 */
  47                if (fs->group_desc[i].bg_block_bitmap < block ||
  48                    fs->group_desc[i].bg_block_bitmap >= next)
  49                        return EXT2_ET_GDESC_BAD_BLOCK_MAP;
  50                /*
  51                 * Check to make sure inode bitmap for group is
  52                 * located within the group
  53                 */
  54                if (fs->group_desc[i].bg_inode_bitmap < block ||
  55                    fs->group_desc[i].bg_inode_bitmap >= next)
  56                        return EXT2_ET_GDESC_BAD_INODE_MAP;
  57                /*
  58                 * Check to make sure inode table for group is located
  59                 * within the group
  60                 */
  61                if (fs->group_desc[i].bg_inode_table < block ||
  62                    ((fs->group_desc[i].bg_inode_table +
  63                      fs->inode_blocks_per_group) >= next))
  64                        return EXT2_ET_GDESC_BAD_INODE_TABLE;
  65
  66                block = next;
  67        }
  68        return 0;
  69}
  70