ext4_common.c

					int new_flags;
					put_ext4((uint64_t)le32_to_cpu(bgd[i].inode_id) * fs->blksz,
						 zero_buffer, fs->blksz);
					new_flags = le16_to_cpu(bgd[i].bg_flags) & ~EXT4_BG_INODE_UNINIT;
					bgd[i].bg_flags = cpu_to_le16(new_flags);
					memcpy(fs->inode_bmaps[i],
					       zero_buffer, fs->blksz);
				}
				fs->curr_inode_no =
				    _get_new_inode_no(fs->inode_bmaps[i]);
				if (fs->curr_inode_no == -1)
					/* if block bitmap is completely fill */
					continue;
				fs->curr_inode_no = fs->curr_inode_no +
							(i * inodes_per_grp);
				fs->first_pass_ibmap++;
				ext4fs_bg_free_inodes_dec(&bgd[i]);
				if (has_gdt_chksum)
					ext4fs_bg_itable_unused_dec(&bgd[i]);
				ext4fs_sb_free_inodes_dec(fs->sb);
				status = ext4fs_devread(
							(lbaint_t)le32_to_cpu(bgd[i].inode_id) *
							fs->sect_perblk, 0,
							fs->blksz,
							journal_buffer);
				if (status == 0)
					goto fail;
				if (ext4fs_log_journal(journal_buffer,
							le32_to_cpu(bgd[i].inode_id)))
					goto fail;
				goto success;
			} else
				debug("no inode left on block group %d\n", i);
		}
		goto fail;
	} else {
restart:
		fs->curr_inode_no++;
		/* get the blockbitmap index respective to blockno */
		ibmap_idx = fs->curr_inode_no / inodes_per_grp;
		if (le16_to_cpu(bgd[ibmap_idx].bg_flags) & EXT4_BG_INODE_UNINIT) {
			int new_flags;
			put_ext4((uint64_t)le32_to_cpu(bgd[ibmap_idx].inode_id) * fs->blksz,
				 zero_buffer, fs->blksz);
			new_flags = le16_to_cpu(bgd[ibmap_idx].bg_flags) & ~EXT4_BG_INODE_UNINIT;
			bgd[ibmap_idx].bg_flags = cpu_to_le16(new_flags);
			memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer,
				fs->blksz);
		}

		if (ext4fs_set_inode_bmap(fs->curr_inode_no,
					  fs->inode_bmaps[ibmap_idx],
					  ibmap_idx) != 0) {
			debug("going for restart for the block no %d %u\n",
			      fs->curr_inode_no, ibmap_idx);
			goto restart;
		}

		/* journal backup */
		if (prev_inode_bitmap_index != ibmap_idx) {
			memset(journal_buffer, '\0', fs->blksz);
			status = ext4fs_devread(
						(lbaint_t)le32_to_cpu(bgd[ibmap_idx].inode_id)
						* fs->sect_perblk,
						0, fs->blksz, journal_buffer);
			if (status == 0)
				goto fail;
			if (ext4fs_log_journal(journal_buffer,
						le32_to_cpu(bgd[ibmap_idx].inode_id)))
				goto fail;
			prev_inode_bitmap_index = ibmap_idx;
		}
		ext4fs_bg_free_inodes_dec(&bgd[ibmap_idx]);
		if (has_gdt_chksum)
			bgd[ibmap_idx].bg_itable_unused =
					bgd[ibmap_idx].free_inodes;
		ext4fs_sb_free_inodes_dec(fs->sb);
		goto success;
	}

success:
	free(journal_buffer);
	free(zero_buffer);

	return fs->curr_inode_no;
fail:
	free(journal_buffer);
	free(zero_buffer);

	return -1;

}


static void alloc_single_indirect_block(struct ext2_inode *file_inode,
					unsigned int *total_remaining_blocks,
					unsigned int *no_blks_reqd)
{
	short i;
	short status;
	long int actual_block_no;
	long int si_blockno;
	/* si :single indirect */
	__le32 *si_buffer = NULL;
	__le32 *si_start_addr = NULL;
	struct ext_filesystem *fs = get_fs();

	if (*total_remaining_blocks != 0) {
		si_buffer = zalloc(fs->blksz);
		if (!si_buffer) {
			printf("No Memory\n");
			return;
		}
		si_start_addr = si_buffer;
		si_blockno = ext4fs_get_new_blk_no();
		if (si_blockno == -1) {
			printf("no block left to assign\n");
			goto fail;
		}
		(*no_blks_reqd)++;
		debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks);

		status = ext4fs_devread((lbaint_t)si_blockno * fs->sect_perblk,
					0, fs->blksz, (char *)si_buffer);
		memset(si_buffer, '\0', fs->blksz);
		if (status == 0)
			goto fail;

		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
			actual_block_no = ext4fs_get_new_blk_no();
			if (actual_block_no == -1) {
				printf("no block left to assign\n");
				goto fail;
			}
			*si_buffer = cpu_to_le32(actual_block_no);
			debug("SIAB %u: %u\n", *si_buffer,
				*total_remaining_blocks);

			si_buffer++;
			(*total_remaining_blocks)--;
			if (*total_remaining_blocks == 0)
				break;
		}

		/* write the block to disk */
		put_ext4(((uint64_t) ((uint64_t)si_blockno * (uint64_t)fs->blksz)),
			 si_start_addr, fs->blksz);
		file_inode->b.blocks.indir_block = cpu_to_le32(si_blockno);
	}
fail:
	free(si_start_addr);
}

static void alloc_double_indirect_block(struct ext2_inode *file_inode,
					unsigned int *total_remaining_blocks,
					unsigned int *no_blks_reqd)
{
	short i;
	short j;
	short status;
	long int actual_block_no;
	/* di:double indirect */
	long int di_blockno_parent;
	long int di_blockno_child;
	__le32 *di_parent_buffer = NULL;
	__le32 *di_child_buff = NULL;
	__le32 *di_block_start_addr = NULL;
	__le32 *di_child_buff_start = NULL;
	struct ext_filesystem *fs = get_fs();

	if (*total_remaining_blocks != 0) {
		/* double indirect parent block connecting to inode */
		di_blockno_parent = ext4fs_get_new_blk_no();
		if (di_blockno_parent == -1) {
			printf("no block left to assign\n");
			goto fail;
		}
		di_parent_buffer = zalloc(fs->blksz);
		if (!di_parent_buffer)
			goto fail;

		di_block_start_addr = di_parent_buffer;
		(*no_blks_reqd)++;
		debug("DIPB %ld: %u\n", di_blockno_parent,
		      *total_remaining_blocks);

		status = ext4fs_devread((lbaint_t)di_blockno_parent *
					fs->sect_perblk, 0,
					fs->blksz, (char *)di_parent_buffer);

		if (!status) {
			printf("%s: Device read error!\n", __func__);
			goto fail;
		}
		memset(di_parent_buffer, '\0', fs->blksz);

		/*
		 * start:for each double indirect parent
		 * block create one more block
		 */
		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
			di_blockno_child = ext4fs_get_new_blk_no();
			if (di_blockno_child == -1) {
				printf("no block left to assign\n");
				goto fail;
			}
			di_child_buff = zalloc(fs->blksz);
			if (!di_child_buff)
				goto fail;

			di_child_buff_start = di_child_buff;
			*di_parent_buffer = cpu_to_le32(di_blockno_child);
			di_parent_buffer++;
			(*no_blks_reqd)++;
			debug("DICB %ld: %u\n", di_blockno_child,
			      *total_remaining_blocks);

			status = ext4fs_devread((lbaint_t)di_blockno_child *
						fs->sect_perblk, 0,
						fs->blksz,
						(char *)di_child_buff);

			if (!status) {
				printf("%s: Device read error!\n", __func__);
				goto fail;
			}
			memset(di_child_buff, '\0', fs->blksz);
			/* filling of actual datablocks for each child */
			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
				actual_block_no = ext4fs_get_new_blk_no();
				if (actual_block_no == -1) {
					printf("no block left to assign\n");
					goto fail;
				}
				*di_child_buff = cpu_to_le32(actual_block_no);
				debug("DIAB %ld: %u\n", actual_block_no,
				      *total_remaining_blocks);

				di_child_buff++;
				(*total_remaining_blocks)--;
				if (*total_remaining_blocks == 0)
					break;
			}
			/* write the block  table */
			put_ext4(((uint64_t) ((uint64_t)di_blockno_child * (uint64_t)fs->blksz)),
				 di_child_buff_start, fs->blksz);
			free(di_child_buff_start);
			di_child_buff_start = NULL;

			if (*total_remaining_blocks == 0)
				break;
		}
		put_ext4(((uint64_t) ((uint64_t)di_blockno_parent * (uint64_t)fs->blksz)),
			 di_block_start_addr, fs->blksz);
		file_inode->b.blocks.double_indir_block = cpu_to_le32(di_blockno_parent);
	}
fail:
	free(di_block_start_addr);
}

static void alloc_triple_indirect_block(struct ext2_inode *file_inode,
					unsigned int *total_remaining_blocks,
					unsigned int *no_blks_reqd)
{
	short i;
	short j;
	short k;
	long int actual_block_no;
	/* ti: Triple Indirect */
	long int ti_gp_blockno;
	long int ti_parent_blockno;
	long int ti_child_blockno;
	__le32 *ti_gp_buff = NULL;
	__le32 *ti_parent_buff = NULL;
	__le32 *ti_child_buff = NULL;
	__le32 *ti_gp_buff_start_addr = NULL;
	__le32 *ti_pbuff_start_addr = NULL;
	__le32 *ti_cbuff_start_addr = NULL;
	struct ext_filesystem *fs = get_fs();
	if (*total_remaining_blocks != 0) {
		/* triple indirect grand parent block connecting to inode */
		ti_gp_blockno = ext4fs_get_new_blk_no();
		if (ti_gp_blockno == -1) {
			printf("no block left to assign\n");
			return;
		}
		ti_gp_buff = zalloc(fs->blksz);
		if (!ti_gp_buff)
			return;

		ti_gp_buff_start_addr = ti_gp_buff;
		(*no_blks_reqd)++;
		debug("TIGPB %ld: %u\n", ti_gp_blockno,
		      *total_remaining_blocks);

		/* for each 4 byte grand parent entry create one more block */
		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
			ti_parent_blockno = ext4fs_get_new_blk_no();
			if (ti_parent_blockno == -1) {
				printf("no block left to assign\n");
				goto fail;
			}
			ti_parent_buff = zalloc(fs->blksz);
			if (!ti_parent_buff)
				goto fail;

			ti_pbuff_start_addr = ti_parent_buff;
			*ti_gp_buff = cpu_to_le32(ti_parent_blockno);
			ti_gp_buff++;
			(*no_blks_reqd)++;
			debug("TIPB %ld: %u\n", ti_parent_blockno,
			      *total_remaining_blocks);

			/* for each 4 byte entry parent create one more block */
			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
				ti_child_blockno = ext4fs_get_new_blk_no();
				if (ti_child_blockno == -1) {
					printf("no block left assign\n");
					goto fail1;
				}
				ti_child_buff = zalloc(fs->blksz);
				if (!ti_child_buff)
					goto fail1;

				ti_cbuff_start_addr = ti_child_buff;
				*ti_parent_buff = cpu_to_le32(ti_child_blockno);
				ti_parent_buff++;
				(*no_blks_reqd)++;
				debug("TICB %ld: %u\n", ti_parent_blockno,
				      *total_remaining_blocks);

				/* fill actual datablocks for each child */
				for (k = 0; k < (fs->blksz / sizeof(int));
					k++) {
					actual_block_no =
					    ext4fs_get_new_blk_no();
					if (actual_block_no == -1) {
						printf("no block left\n");
						free(ti_cbuff_start_addr);
						goto fail1;
					}
					*ti_child_buff = cpu_to_le32(actual_block_no);
					debug("TIAB %ld: %u\n", actual_block_no,
					      *total_remaining_blocks);

					ti_child_buff++;
					(*total_remaining_blocks)--;
					if (*total_remaining_blocks == 0)
						break;
				}
				/* write the child block */
				put_ext4(((uint64_t) ((uint64_t)ti_child_blockno *
						      (uint64_t)fs->blksz)),
					 ti_cbuff_start_addr, fs->blksz);
				free(ti_cbuff_start_addr);

				if (*total_remaining_blocks == 0)
					break;
			}
			/* write the parent block */
			put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)),
				 ti_pbuff_start_addr, fs->blksz);
			free(ti_pbuff_start_addr);

			if (*total_remaining_blocks == 0)
				break;
		}
		/* write the grand parent block */
		put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)),
			 ti_gp_buff_start_addr, fs->blksz);
		file_inode->b.blocks.triple_indir_block = cpu_to_le32(ti_gp_blockno);
		free(ti_gp_buff_start_addr);
		return;
	}
fail1:
	free(ti_pbuff_start_addr);
fail:
	free(ti_gp_buff_start_addr);
}

void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
				unsigned int total_remaining_blocks,
				unsigned int *total_no_of_block)
{
	short i;
	long int direct_blockno;
	unsigned int no_blks_reqd = 0;

	/* allocation of direct blocks */
	for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) {
		direct_blockno = ext4fs_get_new_blk_no();
		if (direct_blockno == -1) {
			printf("no block left to assign\n");
			return;
		}
		file_inode->b.blocks.dir_blocks[i] = cpu_to_le32(direct_blockno);
		debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks);

		total_remaining_blocks--;
	}

	alloc_single_indirect_block(file_inode, &total_remaining_blocks,
				    &no_blks_reqd);
	alloc_double_indirect_block(file_inode, &total_remaining_blocks,
				    &no_blks_reqd);
	alloc_triple_indirect_block(file_inode, &total_remaining_blocks,
				    &no_blks_reqd);
	*total_no_of_block += no_blks_reqd;
}

#endif

static struct ext4_extent_header *ext4fs_get_extent_block
	(struct ext2_data *data, char *buf,
		struct ext4_extent_header *ext_block,
		uint32_t fileblock, int log2_blksz)
{
	struct ext4_extent_idx *index;
	unsigned long long block;
	int blksz = EXT2_BLOCK_SIZE(data);
	int i;

	while (1) {
		index = (struct ext4_extent_idx *)(ext_block + 1);

		if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
			return NULL;

		if (ext_block->eh_depth == 0)
			return ext_block;
		i = -1;
		do {
			i++;
			if (i >= le16_to_cpu(ext_block->eh_entries))
				break;
		} while (fileblock >= le32_to_cpu(index[i].ei_block));

		if (--i < 0)
			return NULL;

		block = le16_to_cpu(index[i].ei_leaf_hi);
		block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);

		if (ext4fs_devread((lbaint_t)block << log2_blksz, 0, blksz,
				   buf))
			ext_block = (struct ext4_extent_header *)buf;
		else
			return NULL;
	}
}

static int ext4fs_blockgroup
	(struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
{
	long int blkno;
	unsigned int blkoff, desc_per_blk;
	int log2blksz = get_fs()->dev_desc->log2blksz;

	desc_per_blk = EXT2_BLOCK_SIZE(data) / sizeof(struct ext2_block_group);

	blkno = le32_to_cpu(data->sblock.first_data_block) + 1 +
			group / desc_per_blk;
	blkoff = (group % desc_per_blk) * sizeof(struct ext2_block_group);

	debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
	      group, blkno, blkoff);

	return ext4fs_devread((lbaint_t)blkno <<
			      (LOG2_BLOCK_SIZE(data) - log2blksz),
			      blkoff, sizeof(struct ext2_block_group),
			      (char *)blkgrp);
}

int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
{
	struct ext2_block_group blkgrp;
	struct ext2_sblock *sblock = &data->sblock;
	struct ext_filesystem *fs = get_fs();
	int log2blksz = get_fs()->dev_desc->log2blksz;
	int inodes_per_block, status;
	long int blkno;
	unsigned int blkoff;

	/* It is easier to calculate if the first inode is 0. */
	ino--;
	status = ext4fs_blockgroup(data, ino / le32_to_cpu
				   (sblock->inodes_per_group), &blkgrp);
	if (status == 0)
		return 0;

	inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
	blkno = le32_to_cpu(blkgrp.inode_table_id) +
	    (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
	blkoff = (ino % inodes_per_block) * fs->inodesz;
	/* Read the inode. */
	status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) -
				log2blksz), blkoff,
				sizeof(struct ext2_inode), (char *)inode);
	if (status == 0)
		return 0;

	return 1;
}

long int read_allocated_block(struct ext2_inode *inode, int fileblock)
{
	long int blknr;
	int blksz;
	int log2_blksz;
	int status;
	long int rblock;
	long int perblock_parent;
	long int perblock_child;
	unsigned long long start;
	/* get the blocksize of the filesystem */
	blksz = EXT2_BLOCK_SIZE(ext4fs_root);
	log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root)
		- get_fs()->dev_desc->log2blksz;

	if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
		char *buf = zalloc(blksz);
		if (!buf)
			return -ENOMEM;
		struct ext4_extent_header *ext_block;
		struct ext4_extent *extent;
		int i = -1;
		ext_block =
			ext4fs_get_extent_block(ext4fs_root, buf,
						(struct ext4_extent_header *)
						inode->b.blocks.dir_blocks,
						fileblock, log2_blksz);
		if (!ext_block) {
			printf("invalid extent block\n");
			free(buf);
			return -EINVAL;
		}

		extent = (struct ext4_extent *)(ext_block + 1);

		do {
			i++;
			if (i >= le16_to_cpu(ext_block->eh_entries))
				break;
		} while (fileblock >= le32_to_cpu(extent[i].ee_block));
		if (--i >= 0) {
			fileblock -= le32_to_cpu(extent[i].ee_block);
			if (fileblock >= le16_to_cpu(extent[i].ee_len)) {
				free(buf);
				return 0;
			}

			start = le16_to_cpu(extent[i].ee_start_hi);
			start = (start << 32) +
					le32_to_cpu(extent[i].ee_start_lo);
			free(buf);
			return fileblock + start;
		}

		printf("Extent Error\n");
		free(buf);
		return -1;
	}

	/* Direct blocks. */
	if (fileblock < INDIRECT_BLOCKS)
		blknr = le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);

	/* Indirect. */
	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
		if (ext4fs_indir1_block == NULL) {
			ext4fs_indir1_block = zalloc(blksz);
			if (ext4fs_indir1_block == NULL) {
				printf("** SI ext2fs read block (indir 1)"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir1_size = blksz;
			ext4fs_indir1_blkno = -1;
		}
		if (blksz != ext4fs_indir1_size) {
			free(ext4fs_indir1_block);
			ext4fs_indir1_block = NULL;
			ext4fs_indir1_size = 0;
			ext4fs_indir1_blkno = -1;
			ext4fs_indir1_block = zalloc(blksz);
			if (ext4fs_indir1_block == NULL) {
				printf("** SI ext2fs read block (indir 1):"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir1_size = blksz;
		}
		if ((le32_to_cpu(inode->b.blocks.indir_block) <<
		     log2_blksz) != ext4fs_indir1_blkno) {
			status =
			    ext4fs_devread((lbaint_t)le32_to_cpu
					   (inode->b.blocks.
					    indir_block) << log2_blksz, 0,
					   blksz, (char *)ext4fs_indir1_block);
			if (status == 0) {
				printf("** SI ext2fs read block (indir 1)"
					"failed. **\n");
				return 0;
			}
			ext4fs_indir1_blkno =
				le32_to_cpu(inode->b.blocks.
					       indir_block) << log2_blksz;
		}
		blknr = le32_to_cpu(ext4fs_indir1_block
				      [fileblock - INDIRECT_BLOCKS]);
	}
	/* Double indirect. */
	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
					(blksz / 4 + 1)))) {

		long int perblock = blksz / 4;
		long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);

		if (ext4fs_indir1_block == NULL) {
			ext4fs_indir1_block = zalloc(blksz);
			if (ext4fs_indir1_block == NULL) {
				printf("** DI ext2fs read block (indir 2 1)"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir1_size = blksz;
			ext4fs_indir1_blkno = -1;
		}
		if (blksz != ext4fs_indir1_size) {
			free(ext4fs_indir1_block);
			ext4fs_indir1_block = NULL;
			ext4fs_indir1_size = 0;
			ext4fs_indir1_blkno = -1;
			ext4fs_indir1_block = zalloc(blksz);
			if (ext4fs_indir1_block == NULL) {
				printf("** DI ext2fs read block (indir 2 1)"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir1_size = blksz;
		}
		if ((le32_to_cpu(inode->b.blocks.double_indir_block) <<
		     log2_blksz) != ext4fs_indir1_blkno) {
			status =
			    ext4fs_devread((lbaint_t)le32_to_cpu
					   (inode->b.blocks.
					    double_indir_block) << log2_blksz,
					   0, blksz,
					   (char *)ext4fs_indir1_block);
			if (status == 0) {
				printf("** DI ext2fs read block (indir 2 1)"
					"failed. **\n");
				return -1;
			}
			ext4fs_indir1_blkno =
			    le32_to_cpu(inode->b.blocks.double_indir_block) <<
			    log2_blksz;
		}

		if (ext4fs_indir2_block == NULL) {
			ext4fs_indir2_block = zalloc(blksz);
			if (ext4fs_indir2_block == NULL) {
				printf("** DI ext2fs read block (indir 2 2)"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir2_size = blksz;
			ext4fs_indir2_blkno = -1;
		}
		if (blksz != ext4fs_indir2_size) {
			free(ext4fs_indir2_block);
			ext4fs_indir2_block = NULL;
			ext4fs_indir2_size = 0;
			ext4fs_indir2_blkno = -1;
			ext4fs_indir2_block = zalloc(blksz);
			if (ext4fs_indir2_block == NULL) {
				printf("** DI ext2fs read block (indir 2 2)"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir2_size = blksz;
		}
		if ((le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
		     log2_blksz) != ext4fs_indir2_blkno) {
			status = ext4fs_devread((lbaint_t)le32_to_cpu
						(ext4fs_indir1_block
						 [rblock /
						  perblock]) << log2_blksz, 0,
						blksz,
						(char *)ext4fs_indir2_block);
			if (status == 0) {
				printf("** DI ext2fs read block (indir 2 2)"
					"failed. **\n");
				return -1;
			}
			ext4fs_indir2_blkno =
			    le32_to_cpu(ext4fs_indir1_block[rblock
							      /
							      perblock]) <<
			    log2_blksz;
		}
		blknr = le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
	}
	/* Tripple indirect. */
	else {
		rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
				      (blksz / 4 * blksz / 4));
		perblock_child = blksz / 4;
		perblock_parent = ((blksz / 4) * (blksz / 4));

		if (ext4fs_indir1_block == NULL) {
			ext4fs_indir1_block = zalloc(blksz);
			if (ext4fs_indir1_block == NULL) {
				printf("** TI ext2fs read block (indir 2 1)"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir1_size = blksz;
			ext4fs_indir1_blkno = -1;
		}
		if (blksz != ext4fs_indir1_size) {
			free(ext4fs_indir1_block);
			ext4fs_indir1_block = NULL;
			ext4fs_indir1_size = 0;
			ext4fs_indir1_blkno = -1;
			ext4fs_indir1_block = zalloc(blksz);
			if (ext4fs_indir1_block == NULL) {
				printf("** TI ext2fs read block (indir 2 1)"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir1_size = blksz;
		}
		if ((le32_to_cpu(inode->b.blocks.triple_indir_block) <<
		     log2_blksz) != ext4fs_indir1_blkno) {
			status = ext4fs_devread
			    ((lbaint_t)
			     le32_to_cpu(inode->b.blocks.triple_indir_block)
			     << log2_blksz, 0, blksz,
			     (char *)ext4fs_indir1_block);
			if (status == 0) {
				printf("** TI ext2fs read block (indir 2 1)"
					"failed. **\n");
				return -1;
			}
			ext4fs_indir1_blkno =
			    le32_to_cpu(inode->b.blocks.triple_indir_block) <<
			    log2_blksz;
		}

		if (ext4fs_indir2_block == NULL) {
			ext4fs_indir2_block = zalloc(blksz);
			if (ext4fs_indir2_block == NULL) {
				printf("** TI ext2fs read block (indir 2 2)"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir2_size = blksz;
			ext4fs_indir2_blkno = -1;
		}
		if (blksz != ext4fs_indir2_size) {
			free(ext4fs_indir2_block);
			ext4fs_indir2_block = NULL;
			ext4fs_indir2_size = 0;
			ext4fs_indir2_blkno = -1;
			ext4fs_indir2_block = zalloc(blksz);
			if (ext4fs_indir2_block == NULL) {
				printf("** TI ext2fs read block (indir 2 2)"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir2_size = blksz;
		}
		if ((le32_to_cpu(ext4fs_indir1_block[rblock /
						       perblock_parent]) <<
		     log2_blksz)
		    != ext4fs_indir2_blkno) {
			status = ext4fs_devread((lbaint_t)le32_to_cpu
						(ext4fs_indir1_block
						 [rblock /
						  perblock_parent]) <<
						log2_blksz, 0, blksz,
						(char *)ext4fs_indir2_block);
			if (status == 0) {
				printf("** TI ext2fs read block (indir 2 2)"
					"failed. **\n");
				return -1;
			}
			ext4fs_indir2_blkno =
			    le32_to_cpu(ext4fs_indir1_block[rblock /
							      perblock_parent])
			    << log2_blksz;
		}

		if (ext4fs_indir3_block == NULL) {
			ext4fs_indir3_block = zalloc(blksz);
			if (ext4fs_indir3_block == NULL) {
				printf("** TI ext2fs read block (indir 2 2)"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir3_size = blksz;
			ext4fs_indir3_blkno = -1;
		}
		if (blksz != ext4fs_indir3_size) {
			free(ext4fs_indir3_block);
			ext4fs_indir3_block = NULL;
			ext4fs_indir3_size = 0;
			ext4fs_indir3_blkno = -1;
			ext4fs_indir3_block = zalloc(blksz);
			if (ext4fs_indir3_block == NULL) {
				printf("** TI ext2fs read block (indir 2 2)"
					"malloc failed. **\n");
				return -1;
			}
			ext4fs_indir3_size = blksz;
		}
		if ((le32_to_cpu(ext4fs_indir2_block[rblock
						       /
						       perblock_child]) <<
		     log2_blksz) != ext4fs_indir3_blkno) {
			status =
			    ext4fs_devread((lbaint_t)le32_to_cpu
					   (ext4fs_indir2_block
					    [(rblock / perblock_child)
					     % (blksz / 4)]) << log2_blksz, 0,
					   blksz, (char *)ext4fs_indir3_block);
			if (status == 0) {
				printf("** TI ext2fs read block (indir 2 2)"
				       "failed. **\n");
				return -1;
			}
			ext4fs_indir3_blkno =
			    le32_to_cpu(ext4fs_indir2_block[(rblock /
							       perblock_child) %
							      (blksz /
							       4)]) <<
			    log2_blksz;
		}

		blknr = le32_to_cpu(ext4fs_indir3_block
				      [rblock % perblock_child]);
	}
	debug("read_allocated_block %ld\n", blknr);

	return blknr;
}

/**
 * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's
 *			    global pointers
 *
 * This function assures that for a file with the same name but different size
 * the sequential store on the ext4 filesystem will be correct.
 *
 * In this function the global data, responsible for internal representation
 * of the ext4 data are initialized to the reset state. Without this, during
 * replacement of the smaller file with the bigger truncation of new file was
 * performed.
 */
void ext4fs_reinit_global(void)
{
	if (ext4fs_indir1_block != NULL) {
		free(ext4fs_indir1_block);
		ext4fs_indir1_block = NULL;
		ext4fs_indir1_size = 0;
		ext4fs_indir1_blkno = -1;
	}
	if (ext4fs_indir2_block != NULL) {
		free(ext4fs_indir2_block);
		ext4fs_indir2_block = NULL;
		ext4fs_indir2_size = 0;
		ext4fs_indir2_blkno = -1;
	}
	if (ext4fs_indir3_block != NULL) {
		free(ext4fs_indir3_block);
		ext4fs_indir3_block = NULL;
		ext4fs_indir3_size = 0;
		ext4fs_indir3_blkno = -1;
	}
}
void ext4fs_close(void)
{
	if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
		ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
		ext4fs_file = NULL;
	}
	if (ext4fs_root != NULL) {
		free(ext4fs_root);
		ext4fs_root = NULL;
	}

	ext4fs_reinit_global();
}

int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
				struct ext2fs_node **fnode, int *ftype)
{
	unsigned int fpos = 0;
	int status;
	loff_t actread;
	struct ext2fs_node *diro = (struct ext2fs_node *) dir;

#ifdef DEBUG
	if (name != NULL)
		printf("Iterate dir %s\n", name);
#endif /* of DEBUG */
	if (!diro->inode_read) {
		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
		if (status == 0)
			return 0;
	}
	/* Search the file.  */
	while (fpos < le32_to_cpu(diro->inode.size)) {
		struct ext2_dirent dirent;

		status = ext4fs_read_file(diro, fpos,
					   sizeof(struct ext2_dirent),
					   (char *)&dirent, &actread);
		if (status < 0)
			return 0;

		if (dirent.direntlen == 0) {
			printf("Failed to iterate over directory %s\n", name);
			return 0;
		}

		if (dirent.namelen != 0) {
			char filename[dirent.namelen + 1];
			struct ext2fs_node *fdiro;
			int type = FILETYPE_UNKNOWN;

			status = ext4fs_read_file(diro,
						  fpos +
						  sizeof(struct ext2_dirent),
						  dirent.namelen, filename,
						  &actread);
			if (status < 0)
				return 0;

			fdiro = zalloc(sizeof(struct ext2fs_node));
			if (!fdiro)
				return 0;

			fdiro->data = diro->data;
			fdiro->ino = le32_to_cpu(dirent.inode);

			filename[dirent.namelen] = '\0';

			if (dirent.filetype != FILETYPE_UNKNOWN) {
				fdiro->inode_read = 0;

				if (dirent.filetype == FILETYPE_DIRECTORY)
					type = FILETYPE_DIRECTORY;
				else if (dirent.filetype == FILETYPE_SYMLINK)
					type = FILETYPE_SYMLINK;
				else if (dirent.filetype == FILETYPE_REG)
					type = FILETYPE_REG;
			} else {
				status = ext4fs_read_inode(diro->data,
							   le32_to_cpu
							   (dirent.inode),
							   &fdiro->inode);
				if (status == 0) {
					free(fdiro);
					return 0;
				}
				fdiro->inode_read = 1;

				if ((le16_to_cpu(fdiro->inode.mode) &
				     FILETYPE_INO_MASK) ==
				    FILETYPE_INO_DIRECTORY) {
					type = FILETYPE_DIRECTORY;
				} else if ((le16_to_cpu(fdiro->inode.mode)
					    & FILETYPE_INO_MASK) ==
					   FILETYPE_INO_SYMLINK) {
					type = FILETYPE_SYMLINK;
				} else if ((le16_to_cpu(fdiro->inode.mode)
					    & FILETYPE_INO_MASK) ==
					   FILETYPE_INO_REG) {
					type = FILETYPE_REG;
				}
			}
#ifdef DEBUG
			printf("iterate >%s<\n", filename);
#endif /* of DEBUG */
			if ((name != NULL) && (fnode != NULL)
			    && (ftype != NULL)) {
				if (strcmp(filename, name) == 0) {
					*ftype = type;
					*fnode = fdiro;
					return 1;
				}
			} else {
				if (fdiro->inode_read == 0) {
					status = ext4fs_read_inode(diro->data,
								 le32_to_cpu(
								 dirent.inode),
								 &fdiro->inode);
					if (status == 0) {