455 lines
11 KiB
C
455 lines
11 KiB
C
/*
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* rw_bitmaps.c --- routines to read and write the inode and block bitmaps.
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*
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* Copyright (C) 1993, 1994, 1994, 1996 Theodore Ts'o.
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*
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* %Begin-Header%
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* This file may be redistributed under the terms of the GNU Library
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* General Public License, version 2.
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* %End-Header%
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*/
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#include "config.h"
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#include <stdio.h>
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#include <string.h>
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#if HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#include <fcntl.h>
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#include <time.h>
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#ifdef HAVE_SYS_STAT_H
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#include <sys/stat.h>
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#endif
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#ifdef HAVE_SYS_TYPES_H
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#include <sys/types.h>
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#endif
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#include "ext2_fs.h"
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#include "ext2fs.h"
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#include "e2image.h"
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static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block)
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{
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dgrp_t i;
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unsigned int j;
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int block_nbytes, inode_nbytes;
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unsigned int nbits;
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errcode_t retval;
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char *block_buf = NULL, *inode_buf = NULL;
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int csum_flag;
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blk64_t blk;
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blk64_t blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
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ext2_ino_t ino_itr = 1;
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EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
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if (!(fs->flags & EXT2_FLAG_RW))
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return EXT2_ET_RO_FILSYS;
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csum_flag = ext2fs_has_group_desc_csum(fs);
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inode_nbytes = block_nbytes = 0;
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if (do_block) {
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block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
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retval = io_channel_alloc_buf(fs->io, 0, &block_buf);
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if (retval)
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goto errout;
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memset(block_buf, 0xff, fs->blocksize);
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}
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if (do_inode) {
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inode_nbytes = (size_t)
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((EXT2_INODES_PER_GROUP(fs->super)+7) / 8);
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retval = io_channel_alloc_buf(fs->io, 0, &inode_buf);
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if (retval)
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goto errout;
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memset(inode_buf, 0xff, fs->blocksize);
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}
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for (i = 0; i < fs->group_desc_count; i++) {
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if (!do_block)
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goto skip_block_bitmap;
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if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT)
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)
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goto skip_this_block_bitmap;
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retval = ext2fs_get_block_bitmap_range2(fs->block_map,
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blk_itr, block_nbytes << 3, block_buf);
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if (retval)
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goto errout;
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if (i == fs->group_desc_count - 1) {
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/* Force bitmap padding for the last group */
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nbits = EXT2FS_NUM_B2C(fs,
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((ext2fs_blocks_count(fs->super)
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- (__u64) fs->super->s_first_data_block)
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% (__u64) EXT2_BLOCKS_PER_GROUP(fs->super)));
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if (nbits)
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for (j = nbits; j < fs->blocksize * 8; j++)
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ext2fs_set_bit(j, block_buf);
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}
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retval = ext2fs_block_bitmap_csum_set(fs, i, block_buf,
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block_nbytes);
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if (retval)
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return retval;
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ext2fs_group_desc_csum_set(fs, i);
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fs->flags |= EXT2_FLAG_DIRTY;
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blk = ext2fs_block_bitmap_loc(fs, i);
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if (blk) {
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retval = io_channel_write_blk64(fs->io, blk, 1,
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block_buf);
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if (retval) {
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retval = EXT2_ET_BLOCK_BITMAP_WRITE;
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goto errout;
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}
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}
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skip_this_block_bitmap:
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blk_itr += block_nbytes << 3;
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skip_block_bitmap:
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if (!do_inode)
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continue;
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if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT)
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)
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goto skip_this_inode_bitmap;
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retval = ext2fs_get_inode_bitmap_range2(fs->inode_map,
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ino_itr, inode_nbytes << 3, inode_buf);
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if (retval)
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goto errout;
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retval = ext2fs_inode_bitmap_csum_set(fs, i, inode_buf,
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inode_nbytes);
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if (retval)
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goto errout;
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ext2fs_group_desc_csum_set(fs, i);
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fs->flags |= EXT2_FLAG_DIRTY;
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blk = ext2fs_inode_bitmap_loc(fs, i);
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if (blk) {
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retval = io_channel_write_blk64(fs->io, blk, 1,
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inode_buf);
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if (retval) {
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retval = EXT2_ET_INODE_BITMAP_WRITE;
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goto errout;
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}
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}
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skip_this_inode_bitmap:
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ino_itr += inode_nbytes << 3;
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}
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if (do_block) {
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fs->flags &= ~EXT2_FLAG_BB_DIRTY;
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ext2fs_free_mem(&block_buf);
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}
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if (do_inode) {
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fs->flags &= ~EXT2_FLAG_IB_DIRTY;
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ext2fs_free_mem(&inode_buf);
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}
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return 0;
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errout:
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if (inode_buf)
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ext2fs_free_mem(&inode_buf);
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if (block_buf)
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ext2fs_free_mem(&block_buf);
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return retval;
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}
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static errcode_t mark_uninit_bg_group_blocks(ext2_filsys fs)
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{
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dgrp_t i;
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blk64_t blk;
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ext2fs_block_bitmap bmap = fs->block_map;
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for (i = 0; i < fs->group_desc_count; i++) {
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if (!ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT))
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continue;
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ext2fs_reserve_super_and_bgd(fs, i, bmap);
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/*
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* Mark the blocks used for the inode table
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*/
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blk = ext2fs_inode_table_loc(fs, i);
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if (blk)
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ext2fs_mark_block_bitmap_range2(bmap, blk,
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fs->inode_blocks_per_group);
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/*
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* Mark block used for the block bitmap
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*/
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blk = ext2fs_block_bitmap_loc(fs, i);
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if (blk)
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ext2fs_mark_block_bitmap2(bmap, blk);
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/*
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* Mark block used for the inode bitmap
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*/
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blk = ext2fs_inode_bitmap_loc(fs, i);
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if (blk)
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ext2fs_mark_block_bitmap2(bmap, blk);
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}
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return 0;
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}
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static int bitmap_tail_verify(unsigned char *bitmap, int first, int last)
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{
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int i;
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for (i = first; i <= last; i++)
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if (bitmap[i] != 0xff)
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return 0;
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return 1;
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}
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static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
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{
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dgrp_t i;
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char *block_bitmap = 0, *inode_bitmap = 0;
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char *buf;
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errcode_t retval;
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int block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
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int inode_nbytes = EXT2_INODES_PER_GROUP(fs->super) / 8;
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int tail_flags = 0;
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int csum_flag;
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unsigned int cnt;
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blk64_t blk;
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blk64_t blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
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blk64_t blk_cnt;
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ext2_ino_t ino_itr = 1;
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ext2_ino_t ino_cnt;
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EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
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if ((block_nbytes > (int) fs->blocksize) ||
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(inode_nbytes > (int) fs->blocksize))
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return EXT2_ET_CORRUPT_SUPERBLOCK;
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fs->write_bitmaps = ext2fs_write_bitmaps;
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csum_flag = ext2fs_has_group_desc_csum(fs);
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retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
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if (retval)
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return retval;
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if (do_block) {
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if (fs->block_map)
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ext2fs_free_block_bitmap(fs->block_map);
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strcpy(buf, "block bitmap for ");
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strcat(buf, fs->device_name);
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retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
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if (retval)
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goto cleanup;
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retval = io_channel_alloc_buf(fs->io, 0, &block_bitmap);
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if (retval)
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goto cleanup;
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} else
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block_nbytes = 0;
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if (do_inode) {
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if (fs->inode_map)
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ext2fs_free_inode_bitmap(fs->inode_map);
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strcpy(buf, "inode bitmap for ");
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strcat(buf, fs->device_name);
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retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
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if (retval)
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goto cleanup;
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retval = io_channel_alloc_buf(fs->io, 0, &inode_bitmap);
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if (retval)
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goto cleanup;
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} else
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inode_nbytes = 0;
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ext2fs_free_mem(&buf);
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if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
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blk = (ext2fs_le32_to_cpu(fs->image_header->offset_inodemap) / fs->blocksize);
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ino_cnt = fs->super->s_inodes_count;
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while (inode_bitmap && ino_cnt > 0) {
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retval = io_channel_read_blk64(fs->image_io, blk++,
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1, inode_bitmap);
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if (retval)
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goto cleanup;
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cnt = fs->blocksize << 3;
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if (cnt > ino_cnt)
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cnt = ino_cnt;
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retval = ext2fs_set_inode_bitmap_range2(fs->inode_map,
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ino_itr, cnt, inode_bitmap);
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if (retval)
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goto cleanup;
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ino_itr += cnt;
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ino_cnt -= cnt;
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}
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blk = (ext2fs_le32_to_cpu(fs->image_header->offset_blockmap) /
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fs->blocksize);
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blk_cnt = EXT2_GROUPS_TO_CLUSTERS(fs->super,
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fs->group_desc_count);
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while (block_bitmap && blk_cnt > 0) {
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retval = io_channel_read_blk64(fs->image_io, blk++,
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1, block_bitmap);
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if (retval)
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goto cleanup;
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cnt = fs->blocksize << 3;
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if (cnt > blk_cnt)
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cnt = blk_cnt;
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retval = ext2fs_set_block_bitmap_range2(fs->block_map,
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blk_itr, cnt, block_bitmap);
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if (retval)
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goto cleanup;
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blk_itr += cnt;
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blk_cnt -= cnt;
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}
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goto success_cleanup;
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}
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for (i = 0; i < fs->group_desc_count; i++) {
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if (block_bitmap) {
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blk = ext2fs_block_bitmap_loc(fs, i);
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if ((csum_flag &&
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ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT) &&
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ext2fs_group_desc_csum_verify(fs, i)) ||
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(blk >= ext2fs_blocks_count(fs->super)))
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blk = 0;
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if (blk) {
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retval = io_channel_read_blk64(fs->io, blk,
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1, block_bitmap);
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if (retval) {
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retval = EXT2_ET_BLOCK_BITMAP_READ;
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goto cleanup;
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}
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/* verify block bitmap checksum */
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if (!(fs->flags &
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EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
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!ext2fs_block_bitmap_csum_verify(fs, i,
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block_bitmap, block_nbytes)) {
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retval =
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EXT2_ET_BLOCK_BITMAP_CSUM_INVALID;
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goto cleanup;
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}
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if (!bitmap_tail_verify((unsigned char *) block_bitmap,
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block_nbytes, fs->blocksize - 1))
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tail_flags |= EXT2_FLAG_BBITMAP_TAIL_PROBLEM;
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} else
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memset(block_bitmap, 0, block_nbytes);
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cnt = block_nbytes << 3;
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retval = ext2fs_set_block_bitmap_range2(fs->block_map,
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blk_itr, cnt, block_bitmap);
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if (retval)
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goto cleanup;
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blk_itr += block_nbytes << 3;
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}
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if (inode_bitmap) {
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blk = ext2fs_inode_bitmap_loc(fs, i);
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if ((csum_flag &&
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ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT) &&
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ext2fs_group_desc_csum_verify(fs, i)) ||
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(blk >= ext2fs_blocks_count(fs->super)))
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blk = 0;
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if (blk) {
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retval = io_channel_read_blk64(fs->io, blk,
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1, inode_bitmap);
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if (retval) {
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retval = EXT2_ET_INODE_BITMAP_READ;
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goto cleanup;
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}
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/* verify inode bitmap checksum */
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if (!(fs->flags &
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EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
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!ext2fs_inode_bitmap_csum_verify(fs, i,
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inode_bitmap, inode_nbytes)) {
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retval =
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EXT2_ET_INODE_BITMAP_CSUM_INVALID;
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goto cleanup;
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}
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if (!bitmap_tail_verify((unsigned char *) inode_bitmap,
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inode_nbytes, fs->blocksize - 1))
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tail_flags |= EXT2_FLAG_IBITMAP_TAIL_PROBLEM;
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} else
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memset(inode_bitmap, 0, inode_nbytes);
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cnt = inode_nbytes << 3;
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retval = ext2fs_set_inode_bitmap_range2(fs->inode_map,
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ino_itr, cnt, inode_bitmap);
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if (retval)
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goto cleanup;
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ino_itr += inode_nbytes << 3;
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}
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}
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/* Mark group blocks for any BLOCK_UNINIT groups */
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if (do_block) {
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retval = mark_uninit_bg_group_blocks(fs);
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if (retval)
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goto cleanup;
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}
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success_cleanup:
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if (inode_bitmap) {
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ext2fs_free_mem(&inode_bitmap);
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fs->flags &= ~EXT2_FLAG_IBITMAP_TAIL_PROBLEM;
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}
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if (block_bitmap) {
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ext2fs_free_mem(&block_bitmap);
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fs->flags &= ~EXT2_FLAG_BBITMAP_TAIL_PROBLEM;
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}
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fs->flags |= tail_flags;
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return 0;
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cleanup:
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if (do_block) {
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ext2fs_free_block_bitmap(fs->block_map);
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fs->block_map = 0;
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}
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if (do_inode) {
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ext2fs_free_inode_bitmap(fs->inode_map);
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fs->inode_map = 0;
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}
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if (inode_bitmap)
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ext2fs_free_mem(&inode_bitmap);
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if (block_bitmap)
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ext2fs_free_mem(&block_bitmap);
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if (buf)
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ext2fs_free_mem(&buf);
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return retval;
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}
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errcode_t ext2fs_read_inode_bitmap(ext2_filsys fs)
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{
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return read_bitmaps(fs, 1, 0);
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}
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errcode_t ext2fs_read_block_bitmap(ext2_filsys fs)
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{
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return read_bitmaps(fs, 0, 1);
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}
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errcode_t ext2fs_write_inode_bitmap(ext2_filsys fs)
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{
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return write_bitmaps(fs, 1, 0);
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}
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errcode_t ext2fs_write_block_bitmap (ext2_filsys fs)
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{
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return write_bitmaps(fs, 0, 1);
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}
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errcode_t ext2fs_read_bitmaps(ext2_filsys fs)
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{
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if (fs->inode_map && fs->block_map)
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return 0;
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return read_bitmaps(fs, !fs->inode_map, !fs->block_map);
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}
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errcode_t ext2fs_write_bitmaps(ext2_filsys fs)
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{
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int do_inode = fs->inode_map && ext2fs_test_ib_dirty(fs);
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int do_block = fs->block_map && ext2fs_test_bb_dirty(fs);
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if (!do_inode && !do_block)
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return 0;
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return write_bitmaps(fs, do_inode, do_block);
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}
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