| /* |
| * check_desc.c --- Check the group descriptors of an ext2 filesystem |
| * |
| * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. |
| * |
| * %Begin-Header% |
| * This file may be redistributed under the terms of the GNU Library |
| * General Public License, version 2. |
| * %End-Header% |
| */ |
| |
| #include <stdio.h> |
| #include <string.h> |
| #if HAVE_UNISTD_H |
| #include <unistd.h> |
| #endif |
| #include <fcntl.h> |
| #include <time.h> |
| #if HAVE_SYS_STAT_H |
| #include <sys/stat.h> |
| #endif |
| #if HAVE_SYS_TYPES_H |
| #include <sys/types.h> |
| #endif |
| |
| #include "ext2_fs.h" |
| #include "ext2fs.h" |
| |
| /* |
| * This routine sanity checks the group descriptors |
| */ |
| errcode_t ext2fs_check_desc(ext2_filsys fs) |
| { |
| ext2fs_block_bitmap bmap; |
| errcode_t retval; |
| dgrp_t i; |
| blk64_t first_block = fs->super->s_first_data_block; |
| blk64_t last_block = ext2fs_blocks_count(fs->super)-1; |
| blk64_t blk, b; |
| unsigned int j; |
| |
| EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
| |
| if (EXT2_DESC_SIZE(fs->super) & (EXT2_DESC_SIZE(fs->super) - 1)) |
| return EXT2_ET_BAD_DESC_SIZE; |
| |
| retval = ext2fs_allocate_subcluster_bitmap(fs, "check_desc map", &bmap); |
| if (retval) |
| return retval; |
| |
| for (i = 0; i < fs->group_desc_count; i++) |
| ext2fs_reserve_super_and_bgd(fs, i, bmap); |
| |
| for (i = 0; i < fs->group_desc_count; i++) { |
| if (!EXT2_HAS_INCOMPAT_FEATURE(fs->super, |
| EXT4_FEATURE_INCOMPAT_FLEX_BG)) { |
| first_block = ext2fs_group_first_block2(fs, i); |
| last_block = ext2fs_group_last_block2(fs, i); |
| } |
| |
| /* |
| * Check to make sure the block bitmap for group is sane |
| */ |
| blk = ext2fs_block_bitmap_loc(fs, i); |
| if (blk < first_block || blk > last_block || |
| ext2fs_test_block_bitmap2(bmap, blk)) { |
| retval = EXT2_ET_GDESC_BAD_BLOCK_MAP; |
| goto errout; |
| } |
| ext2fs_mark_block_bitmap2(bmap, blk); |
| |
| /* |
| * Check to make sure the inode bitmap for group is sane |
| */ |
| blk = ext2fs_inode_bitmap_loc(fs, i); |
| if (blk < first_block || blk > last_block || |
| ext2fs_test_block_bitmap2(bmap, blk)) { |
| retval = EXT2_ET_GDESC_BAD_INODE_MAP; |
| goto errout; |
| } |
| ext2fs_mark_block_bitmap2(bmap, blk); |
| |
| /* |
| * Check to make sure the inode table for group is sane |
| */ |
| blk = ext2fs_inode_table_loc(fs, i); |
| if (blk < first_block || |
| ((blk + fs->inode_blocks_per_group - 1) > last_block)) { |
| retval = EXT2_ET_GDESC_BAD_INODE_TABLE; |
| goto errout; |
| } |
| for (j = 0, b = blk; j < fs->inode_blocks_per_group; |
| j++, b++) { |
| if (ext2fs_test_block_bitmap2(bmap, b)) { |
| retval = EXT2_ET_GDESC_BAD_INODE_TABLE; |
| goto errout; |
| } |
| ext2fs_mark_block_bitmap2(bmap, b); |
| } |
| } |
| errout: |
| ext2fs_free_block_bitmap(bmap); |
| return retval; |
| } |