ASR_BASE

Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/uboot/fs/ext4/ext4_common.c b/marvell/uboot/fs/ext4/ext4_common.c
new file mode 100644
index 0000000..02da75c
--- /dev/null
+++ b/marvell/uboot/fs/ext4/ext4_common.c
@@ -0,0 +1,2235 @@
+/*
+ * (C) Copyright 2011 - 2012 Samsung Electronics
+ * EXT4 filesystem implementation in Uboot by
+ * Uma Shankar <uma.shankar@samsung.com>
+ * Manjunatha C Achar <a.manjunatha@samsung.com>
+ *
+ * ext4ls and ext4load : Based on ext2 ls load support in Uboot.
+ *
+ * (C) Copyright 2004
+ * esd gmbh <www.esd-electronics.com>
+ * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
+ *
+ * based on code from grub2 fs/ext2.c and fs/fshelp.c by
+ * GRUB  --  GRand Unified Bootloader
+ * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
+ *
+ * ext4write : Based on generic ext4 protocol.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <ext_common.h>
+#include <ext4fs.h>
+#include <malloc.h>
+#include <stddef.h>
+#include <linux/stat.h>
+#include <linux/time.h>
+#include <asm/byteorder.h>
+#include "ext4_common.h"
+
+struct ext2_data *ext4fs_root;
+struct ext2fs_node *ext4fs_file;
+uint32_t *ext4fs_indir1_block;
+int ext4fs_indir1_size;
+int ext4fs_indir1_blkno = -1;
+uint32_t *ext4fs_indir2_block;
+int ext4fs_indir2_size;
+int ext4fs_indir2_blkno = -1;
+
+uint32_t *ext4fs_indir3_block;
+int ext4fs_indir3_size;
+int ext4fs_indir3_blkno = -1;
+struct ext2_inode *g_parent_inode;
+static int symlinknest;
+
+#if defined(CONFIG_EXT4_WRITE)
+uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n)
+{
+	uint32_t res = size / n;
+	if (res * n != size)
+		res++;
+
+	return res;
+}
+
+void put_ext4(uint64_t off, void *buf, uint32_t size)
+{
+	uint64_t startblock;
+	uint64_t remainder;
+	unsigned char *temp_ptr = NULL;
+	struct ext_filesystem *fs = get_fs();
+	int log2blksz = fs->dev_desc->log2blksz;
+	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, sec_buf, fs->dev_desc->blksz);
+
+	startblock = off >> log2blksz;
+	startblock += part_offset;
+	remainder = off & (uint64_t)(fs->dev_desc->blksz - 1);
+
+	if (fs->dev_desc == NULL)
+		return;
+
+	if ((startblock + (size >> log2blksz)) >
+	    (part_offset + fs->total_sect)) {
+		printf("part_offset is " LBAFU "\n", part_offset);
+		printf("total_sector is %llu\n", fs->total_sect);
+		printf("error: overflow occurs\n");
+		return;
+	}
+
+	if (remainder) {
+		if (fs->dev_desc->block_read) {
+			fs->dev_desc->block_read(fs->dev_desc->dev,
+						 startblock, 1, sec_buf);
+			temp_ptr = sec_buf;
+			memcpy((temp_ptr + remainder),
+			       (unsigned char *)buf, size);
+			fs->dev_desc->block_write(fs->dev_desc->dev,
+						  startblock, 1, sec_buf);
+		}
+	} else {
+		if (size >> log2blksz != 0) {
+			fs->dev_desc->block_write(fs->dev_desc->dev,
+						  startblock,
+						  size >> log2blksz,
+						  (unsigned long *)buf);
+		} else {
+			fs->dev_desc->block_read(fs->dev_desc->dev,
+						 startblock, 1, sec_buf);
+			temp_ptr = sec_buf;
+			memcpy(temp_ptr, buf, size);
+			fs->dev_desc->block_write(fs->dev_desc->dev,
+						  startblock, 1,
+						  (unsigned long *)sec_buf);
+		}
+	}
+}
+
+static int _get_new_inode_no(unsigned char *buffer)
+{
+	struct ext_filesystem *fs = get_fs();
+	unsigned char input;
+	int operand, status;
+	int count = 1;
+	int j = 0;
+
+	/* get the blocksize of the filesystem */
+	unsigned char *ptr = buffer;
+	while (*ptr == 255) {
+		ptr++;
+		count += 8;
+		if (count > ext4fs_root->sblock.inodes_per_group)
+			return -1;
+	}
+
+	for (j = 0; j < fs->blksz; j++) {
+		input = *ptr;
+		int i = 0;
+		while (i <= 7) {
+			operand = 1 << i;
+			status = input & operand;
+			if (status) {
+				i++;
+				count++;
+			} else {
+				*ptr |= operand;
+				return count;
+			}
+		}
+		ptr = ptr + 1;
+	}
+
+	return -1;
+}
+
+static int _get_new_blk_no(unsigned char *buffer)
+{
+	unsigned char input;
+	int operand, status;
+	int count = 0;
+	int j = 0;
+	unsigned char *ptr = buffer;
+	struct ext_filesystem *fs = get_fs();
+
+	if (fs->blksz != 1024)
+		count = 0;
+	else
+		count = 1;
+
+	while (*ptr == 255) {
+		ptr++;
+		count += 8;
+		if (count == (fs->blksz * 8))
+			return -1;
+	}
+
+	for (j = 0; j < fs->blksz; j++) {
+		input = *ptr;
+		int i = 0;
+		while (i <= 7) {
+			operand = 1 << i;
+			status = input & operand;
+			if (status) {
+				i++;
+				count++;
+			} else {
+				*ptr |= operand;
+				return count;
+			}
+		}
+		ptr = ptr + 1;
+	}
+
+	return -1;
+}
+
+int ext4fs_set_block_bmap(long int blockno, unsigned char *buffer, int index)
+{
+	int i, remainder, status;
+	unsigned char *ptr = buffer;
+	unsigned char operand;
+	i = blockno / 8;
+	remainder = blockno % 8;
+	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
+
+	i = i - (index * blocksize);
+	if (blocksize != 1024) {
+		ptr = ptr + i;
+		operand = 1 << remainder;
+		status = *ptr & operand;
+		if (status)
+			return -1;
+
+		*ptr = *ptr | operand;
+		return 0;
+	} else {
+		if (remainder == 0) {
+			ptr = ptr + i - 1;
+			operand = (1 << 7);
+		} else {
+			ptr = ptr + i;
+			operand = (1 << (remainder - 1));
+		}
+		status = *ptr & operand;
+		if (status)
+			return -1;
+
+		*ptr = *ptr | operand;
+		return 0;
+	}
+}
+
+void ext4fs_reset_block_bmap(long int blockno, unsigned char *buffer, int index)
+{
+	int i, remainder, status;
+	unsigned char *ptr = buffer;
+	unsigned char operand;
+	i = blockno / 8;
+	remainder = blockno % 8;
+	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
+
+	i = i - (index * blocksize);
+	if (blocksize != 1024) {
+		ptr = ptr + i;
+		operand = (1 << remainder);
+		status = *ptr & operand;
+		if (status)
+			*ptr = *ptr & ~(operand);
+	} else {
+		if (remainder == 0) {
+			ptr = ptr + i - 1;
+			operand = (1 << 7);
+		} else {
+			ptr = ptr + i;
+			operand = (1 << (remainder - 1));
+		}
+		status = *ptr & operand;
+		if (status)
+			*ptr = *ptr & ~(operand);
+	}
+}
+
+int ext4fs_set_inode_bmap(int inode_no, unsigned char *buffer, int index)
+{
+	int i, remainder, status;
+	unsigned char *ptr = buffer;
+	unsigned char operand;
+
+	inode_no -= (index * ext4fs_root->sblock.inodes_per_group);
+	i = inode_no / 8;
+	remainder = inode_no % 8;
+	if (remainder == 0) {
+		ptr = ptr + i - 1;
+		operand = (1 << 7);
+	} else {
+		ptr = ptr + i;
+		operand = (1 << (remainder - 1));
+	}
+	status = *ptr & operand;
+	if (status)
+		return -1;
+
+	*ptr = *ptr | operand;
+
+	return 0;
+}
+
+void ext4fs_reset_inode_bmap(int inode_no, unsigned char *buffer, int index)
+{
+	int i, remainder, status;
+	unsigned char *ptr = buffer;
+	unsigned char operand;
+
+	inode_no -= (index * ext4fs_root->sblock.inodes_per_group);
+	i = inode_no / 8;
+	remainder = inode_no % 8;
+	if (remainder == 0) {
+		ptr = ptr + i - 1;
+		operand = (1 << 7);
+	} else {
+		ptr = ptr + i;
+		operand = (1 << (remainder - 1));
+	}
+	status = *ptr & operand;
+	if (status)
+		*ptr = *ptr & ~(operand);
+}
+
+int ext4fs_checksum_update(unsigned int i)
+{
+	struct ext2_block_group *desc;
+	struct ext_filesystem *fs = get_fs();
+	__u16 crc = 0;
+
+	desc = (struct ext2_block_group *)&fs->bgd[i];
+	if (fs->sb->feature_ro_compat & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
+		int offset = offsetof(struct ext2_block_group, bg_checksum);
+
+		crc = ext2fs_crc16(~0, fs->sb->unique_id,
+				   sizeof(fs->sb->unique_id));
+		crc = ext2fs_crc16(crc, &i, sizeof(i));
+		crc = ext2fs_crc16(crc, desc, offset);
+		offset += sizeof(desc->bg_checksum);	/* skip checksum */
+		assert(offset == sizeof(*desc));
+	}
+
+	return crc;
+}
+
+static int check_void_in_dentry(struct ext2_dirent *dir, char *filename)
+{
+	int dentry_length;
+	int sizeof_void_space;
+	int new_entry_byte_reqd;
+	short padding_factor = 0;
+
+	if (dir->namelen % 4 != 0)
+		padding_factor = 4 - (dir->namelen % 4);
+
+	dentry_length = sizeof(struct ext2_dirent) +
+			dir->namelen + padding_factor;
+	sizeof_void_space = dir->direntlen - dentry_length;
+	if (sizeof_void_space == 0)
+		return 0;
+
+	padding_factor = 0;
+	if (strlen(filename) % 4 != 0)
+		padding_factor = 4 - (strlen(filename) % 4);
+
+	new_entry_byte_reqd = strlen(filename) +
+	    sizeof(struct ext2_dirent) + padding_factor;
+	if (sizeof_void_space >= new_entry_byte_reqd) {
+		dir->direntlen = dentry_length;
+		return sizeof_void_space;
+	}
+
+	return 0;
+}
+
+void ext4fs_update_parent_dentry(char *filename, int *p_ino, int file_type)
+{
+	unsigned int *zero_buffer = NULL;
+	char *root_first_block_buffer = NULL;
+	int direct_blk_idx;
+	long int root_blknr;
+	long int first_block_no_of_root = 0;
+	long int previous_blknr = -1;
+	int totalbytes = 0;
+	short int padding_factor = 0;
+	unsigned int new_entry_byte_reqd;
+	unsigned int last_entry_dirlen;
+	int sizeof_void_space = 0;
+	int templength = 0;
+	int inodeno;
+	int status;
+	struct ext_filesystem *fs = get_fs();
+	/* directory entry */
+	struct ext2_dirent *dir;
+	char *temp_dir = NULL;
+
+	zero_buffer = zalloc(fs->blksz);
+	if (!zero_buffer) {
+		printf("No Memory\n");
+		return;
+	}
+	root_first_block_buffer = zalloc(fs->blksz);
+	if (!root_first_block_buffer) {
+		free(zero_buffer);
+		printf("No Memory\n");
+		return;
+	}
+restart:
+
+	/* read the block no allocated to a file */
+	for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS;
+	     direct_blk_idx++) {
+		root_blknr = read_allocated_block(g_parent_inode,
+						  direct_blk_idx);
+		if (root_blknr == 0) {
+			first_block_no_of_root = previous_blknr;
+			break;
+		}
+		previous_blknr = root_blknr;
+	}
+
+	status = ext4fs_devread((lbaint_t)first_block_no_of_root
+				* fs->sect_perblk,
+				0, fs->blksz, root_first_block_buffer);
+	if (status == 0)
+		goto fail;
+
+	if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root))
+		goto fail;
+	dir = (struct ext2_dirent *)root_first_block_buffer;
+	totalbytes = 0;
+	while (dir->direntlen > 0) {
+		/*
+		 * blocksize-totalbytes because last directory length
+		 * i.e. dir->direntlen is free availble space in the
+		 * block that means  it is a last entry of directory
+		 * entry
+		 */
+
+		/* traversing the each directory entry */
+		if (fs->blksz - totalbytes == dir->direntlen) {
+			if (strlen(filename) % 4 != 0)
+				padding_factor = 4 - (strlen(filename) % 4);
+
+			new_entry_byte_reqd = strlen(filename) +
+			    sizeof(struct ext2_dirent) + padding_factor;
+			padding_factor = 0;
+			/*
+			 * update last directory entry length to its
+			 * length because we are creating new directory
+			 * entry
+			 */
+			if (dir->namelen % 4 != 0)
+				padding_factor = 4 - (dir->namelen % 4);
+
+			last_entry_dirlen = dir->namelen +
+			    sizeof(struct ext2_dirent) + padding_factor;
+			if ((fs->blksz - totalbytes - last_entry_dirlen) <
+				new_entry_byte_reqd) {
+				printf("1st Block Full:Allocate new block\n");
+
+				if (direct_blk_idx == INDIRECT_BLOCKS - 1) {
+					printf("Directory exceeds limit\n");
+					goto fail;
+				}
+				g_parent_inode->b.blocks.dir_blocks
+				    [direct_blk_idx] = ext4fs_get_new_blk_no();
+				if (g_parent_inode->b.blocks.dir_blocks
+					[direct_blk_idx] == -1) {
+					printf("no block left to assign\n");
+					goto fail;
+				}
+				put_ext4(((uint64_t)
+					  ((uint64_t)g_parent_inode->b.
+					   blocks.dir_blocks[direct_blk_idx] *
+					   (uint64_t)fs->blksz)), zero_buffer, fs->blksz);
+				g_parent_inode->size =
+				    g_parent_inode->size + fs->blksz;
+				g_parent_inode->blockcnt =
+				    g_parent_inode->blockcnt + fs->sect_perblk;
+				if (ext4fs_put_metadata
+				    (root_first_block_buffer,
+				     first_block_no_of_root))
+					goto fail;
+				goto restart;
+			}
+			dir->direntlen = last_entry_dirlen;
+			break;
+		}
+
+		templength = dir->direntlen;
+		totalbytes = totalbytes + templength;
+		sizeof_void_space = check_void_in_dentry(dir, filename);
+		if (sizeof_void_space)
+			break;
+
+		dir = (struct ext2_dirent *)((char *)dir + templength);
+	}
+
+	/* make a pointer ready for creating next directory entry */
+	templength = dir->direntlen;
+	totalbytes = totalbytes + templength;
+	dir = (struct ext2_dirent *)((char *)dir + templength);
+
+	/* get the next available inode number */
+	inodeno = ext4fs_get_new_inode_no();
+	if (inodeno == -1) {
+		printf("no inode left to assign\n");
+		goto fail;
+	}
+	dir->inode = inodeno;
+	if (sizeof_void_space)
+		dir->direntlen = sizeof_void_space;
+	else
+		dir->direntlen = fs->blksz - totalbytes;
+
+	dir->namelen = strlen(filename);
+	dir->filetype = FILETYPE_REG;	/* regular file */
+	temp_dir = (char *)dir;
+	temp_dir = temp_dir + sizeof(struct ext2_dirent);
+	memcpy(temp_dir, filename, strlen(filename));
+
+	*p_ino = inodeno;
+
+	/* update or write  the 1st block of root inode */
+	if (ext4fs_put_metadata(root_first_block_buffer,
+				first_block_no_of_root))
+		goto fail;
+
+fail:
+	free(zero_buffer);
+	free(root_first_block_buffer);
+}
+
+static int search_dir(struct ext2_inode *parent_inode, char *dirname)
+{
+	int status;
+	int inodeno;
+	int totalbytes;
+	int templength;
+	int direct_blk_idx;
+	long int blknr;
+	int found = 0;
+	char *ptr = NULL;
+	unsigned char *block_buffer = NULL;
+	struct ext2_dirent *dir = NULL;
+	struct ext2_dirent *previous_dir = NULL;
+	struct ext_filesystem *fs = get_fs();
+
+	/* read the block no allocated to a file */
+	for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS;
+		direct_blk_idx++) {
+		blknr = read_allocated_block(parent_inode, direct_blk_idx);
+		if (blknr == 0)
+			goto fail;
+
+		/* read the blocks of parenet inode */
+		block_buffer = zalloc(fs->blksz);
+		if (!block_buffer)
+			goto fail;
+
+		status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk,
+					0, fs->blksz, (char *)block_buffer);
+		if (status == 0)
+			goto fail;
+
+		dir = (struct ext2_dirent *)block_buffer;
+		ptr = (char *)dir;
+		totalbytes = 0;
+		while (dir->direntlen >= 0) {
+			/*
+			 * blocksize-totalbytes because last directory
+			 * length i.e.,*dir->direntlen is free availble
+			 * space in the block that means
+			 * it is a last entry of directory entry
+			 */
+			if (strlen(dirname) == dir->namelen) {
+				if (strncmp(dirname, ptr +
+					sizeof(struct ext2_dirent),
+					dir->namelen) == 0) {
+					previous_dir->direntlen +=
+							dir->direntlen;
+					inodeno = dir->inode;
+					dir->inode = 0;
+					found = 1;
+					break;
+				}
+			}
+
+			if (fs->blksz - totalbytes == dir->direntlen)
+				break;
+
+			/* traversing the each directory entry */
+			templength = dir->direntlen;
+			totalbytes = totalbytes + templength;
+			previous_dir = dir;
+			dir = (struct ext2_dirent *)((char *)dir + templength);
+			ptr = (char *)dir;
+		}
+
+		if (found == 1) {
+			free(block_buffer);
+			block_buffer = NULL;
+			return inodeno;
+		}
+
+		free(block_buffer);
+		block_buffer = NULL;
+	}
+
+fail:
+	free(block_buffer);
+
+	return -1;
+}
+
+static int find_dir_depth(char *dirname)
+{
+	char *token = strtok(dirname, "/");
+	int count = 0;
+	while (token != NULL) {
+		token = strtok(NULL, "/");
+		count++;
+	}
+	return count + 1 + 1;
+	/*
+	 * for example  for string /home/temp
+	 * depth=home(1)+temp(1)+1 extra for NULL;
+	 * so count is 4;
+	 */
+}
+
+static int parse_path(char **arr, char *dirname)
+{
+	char *token = strtok(dirname, "/");
+	int i = 0;
+
+	/* add root */
+	arr[i] = zalloc(strlen("/") + 1);
+	if (!arr[i])
+		return -ENOMEM;
+
+	arr[i++] = "/";
+
+	/* add each path entry after root */
+	while (token != NULL) {
+		arr[i] = zalloc(strlen(token) + 1);
+		if (!arr[i])
+			return -ENOMEM;
+		memcpy(arr[i++], token, strlen(token));
+		token = strtok(NULL, "/");
+	}
+	arr[i] = NULL;
+
+	return 0;
+}
+
+int ext4fs_iget(int inode_no, struct ext2_inode *inode)
+{
+	if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0)
+		return -1;
+
+	return 0;
+}
+
+/*
+ * Function: ext4fs_get_parent_inode_num
+ * Return Value: inode Number of the parent directory of  file/Directory to be
+ * created
+ * dirname : Input parmater, input path name of the file/directory to be created
+ * dname : Output parameter, to be filled with the name of the directory
+ * extracted from dirname
+ */
+int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags)
+{
+	int i;
+	int depth = 0;
+	int matched_inode_no;
+	int result_inode_no = -1;
+	char **ptr = NULL;
+	char *depth_dirname = NULL;
+	char *parse_dirname = NULL;
+	struct ext2_inode *parent_inode = NULL;
+	struct ext2_inode *first_inode = NULL;
+	struct ext2_inode temp_inode;
+
+	if (*dirname != '/') {
+		printf("Please supply Absolute path\n");
+		return -1;
+	}
+
+	/* TODO: input validation make equivalent to linux */
+	depth_dirname = zalloc(strlen(dirname) + 1);
+	if (!depth_dirname)
+		return -ENOMEM;
+
+	memcpy(depth_dirname, dirname, strlen(dirname));
+	depth = find_dir_depth(depth_dirname);
+	parse_dirname = zalloc(strlen(dirname) + 1);
+	if (!parse_dirname)
+		goto fail;
+	memcpy(parse_dirname, dirname, strlen(dirname));
+
+	/* allocate memory for each directory level */
+	ptr = zalloc((depth) * sizeof(char *));
+	if (!ptr)
+		goto fail;
+	if (parse_path(ptr, parse_dirname))
+		goto fail;
+	parent_inode = zalloc(sizeof(struct ext2_inode));
+	if (!parent_inode)
+		goto fail;
+	first_inode = zalloc(sizeof(struct ext2_inode));
+	if (!first_inode)
+		goto fail;
+	memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode));
+	memcpy(first_inode, parent_inode, sizeof(struct ext2_inode));
+	if (flags & F_FILE)
+		result_inode_no = EXT2_ROOT_INO;
+	for (i = 1; i < depth; i++) {
+		matched_inode_no = search_dir(parent_inode, ptr[i]);
+		if (matched_inode_no == -1) {
+			if (ptr[i + 1] == NULL && i == 1) {
+				result_inode_no = EXT2_ROOT_INO;
+				goto end;
+			} else {
+				if (ptr[i + 1] == NULL)
+					break;
+				printf("Invalid path\n");
+				result_inode_no = -1;
+				goto fail;
+			}
+		} else {
+			if (ptr[i + 1] != NULL) {
+				memset(parent_inode, '\0',
+				       sizeof(struct ext2_inode));
+				if (ext4fs_iget(matched_inode_no,
+						parent_inode)) {
+					result_inode_no = -1;
+					goto fail;
+				}
+				result_inode_no = matched_inode_no;
+			} else {
+				break;
+			}
+		}
+	}
+
+end:
+	if (i == 1)
+		matched_inode_no = search_dir(first_inode, ptr[i]);
+	else
+		matched_inode_no = search_dir(parent_inode, ptr[i]);
+
+	if (matched_inode_no != -1) {
+		ext4fs_iget(matched_inode_no, &temp_inode);
+		if (temp_inode.mode & S_IFDIR) {
+			printf("It is a Directory\n");
+			result_inode_no = -1;
+			goto fail;
+		}
+	}
+
+	if (strlen(ptr[i]) > 256) {
+		result_inode_no = -1;
+		goto fail;
+	}
+	memcpy(dname, ptr[i], strlen(ptr[i]));
+
+fail:
+	free(depth_dirname);
+	free(parse_dirname);
+	free(ptr);
+	free(parent_inode);
+	free(first_inode);
+
+	return result_inode_no;
+}
+
+static int check_filename(char *filename, unsigned int blknr)
+{
+	unsigned int first_block_no_of_root;
+	int totalbytes = 0;
+	int templength = 0;
+	int status, inodeno;
+	int found = 0;
+	char *root_first_block_buffer = NULL;
+	char *root_first_block_addr = NULL;
+	struct ext2_dirent *dir = NULL;
+	struct ext2_dirent *previous_dir = NULL;
+	char *ptr = NULL;
+	struct ext_filesystem *fs = get_fs();
+
+	/* get the first block of root */
+	first_block_no_of_root = blknr;
+	root_first_block_buffer = zalloc(fs->blksz);
+	if (!root_first_block_buffer)
+		return -ENOMEM;
+	root_first_block_addr = root_first_block_buffer;
+	status = ext4fs_devread((lbaint_t)first_block_no_of_root *
+				fs->sect_perblk, 0,
+				fs->blksz, root_first_block_buffer);
+	if (status == 0)
+		goto fail;
+
+	if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root))
+		goto fail;
+	dir = (struct ext2_dirent *)root_first_block_buffer;
+	ptr = (char *)dir;
+	totalbytes = 0;
+	while (dir->direntlen >= 0) {
+		/*
+		 * blocksize-totalbytes because last
+		 * directory length i.e., *dir->direntlen
+		 * is free availble space in the block that
+		 * means it is a last entry of directory entry
+		 */
+		if (strlen(filename) == dir->namelen) {
+			if (strncmp(filename, ptr + sizeof(struct ext2_dirent),
+				dir->namelen) == 0) {
+				printf("file found deleting\n");
+				previous_dir->direntlen += dir->direntlen;
+				inodeno = dir->inode;
+				dir->inode = 0;
+				found = 1;
+				break;
+			}
+		}
+
+		if (fs->blksz - totalbytes == dir->direntlen)
+			break;
+
+		/* traversing the each directory entry */
+		templength = dir->direntlen;
+		totalbytes = totalbytes + templength;
+		previous_dir = dir;
+		dir = (struct ext2_dirent *)((char *)dir + templength);
+		ptr = (char *)dir;
+	}
+
+
+	if (found == 1) {
+		if (ext4fs_put_metadata(root_first_block_addr,
+					first_block_no_of_root))
+			goto fail;
+		return inodeno;
+	}
+fail:
+	free(root_first_block_buffer);
+
+	return -1;
+}
+
+int ext4fs_filename_check(char *filename)
+{
+	short direct_blk_idx = 0;
+	long int blknr = -1;
+	int inodeno = -1;
+
+	/* read the block no allocated to a file */
+	for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS;
+		direct_blk_idx++) {
+		blknr = read_allocated_block(g_parent_inode, direct_blk_idx);
+		if (blknr == 0)
+			break;
+		inodeno = check_filename(filename, blknr);
+		if (inodeno != -1)
+			return inodeno;
+	}
+
+	return -1;
+}
+
+long int ext4fs_get_new_blk_no(void)
+{
+	short i;
+	short status;
+	int remainder;
+	unsigned int bg_idx;
+	static int prev_bg_bitmap_index = -1;
+	unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
+	struct ext_filesystem *fs = get_fs();
+	char *journal_buffer = zalloc(fs->blksz);
+	char *zero_buffer = zalloc(fs->blksz);
+	if (!journal_buffer || !zero_buffer)
+		goto fail;
+	struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable;
+
+	if (fs->first_pass_bbmap == 0) {
+		for (i = 0; i < fs->no_blkgrp; i++) {
+			if (bgd[i].free_blocks) {
+				if (bgd[i].bg_flags & EXT4_BG_BLOCK_UNINIT) {
+					put_ext4(((uint64_t) ((uint64_t)bgd[i].block_id *
+							      (uint64_t)fs->blksz)),
+						 zero_buffer, fs->blksz);
+					bgd[i].bg_flags =
+					    bgd[i].
+					    bg_flags & ~EXT4_BG_BLOCK_UNINIT;
+					memcpy(fs->blk_bmaps[i], zero_buffer,
+					       fs->blksz);
+				}
+				fs->curr_blkno =
+				    _get_new_blk_no(fs->blk_bmaps[i]);
+				if (fs->curr_blkno == -1)
+					/* if block bitmap is completely fill */
+					continue;
+				fs->curr_blkno = fs->curr_blkno +
+						(i * fs->blksz * 8);
+				fs->first_pass_bbmap++;
+				bgd[i].free_blocks--;
+				fs->sb->free_blocks--;
+				status = ext4fs_devread((lbaint_t)
+							bgd[i].block_id *
+							fs->sect_perblk, 0,
+							fs->blksz,
+							journal_buffer);
+				if (status == 0)
+					goto fail;
+				if (ext4fs_log_journal(journal_buffer,
+							bgd[i].block_id))
+					goto fail;
+				goto success;
+			} else {
+				debug("no space left on block group %d\n", i);
+			}
+		}
+
+		goto fail;
+	} else {
+restart:
+		fs->curr_blkno++;
+		/* get the blockbitmap index respective to blockno */
+		if (fs->blksz != 1024) {
+			bg_idx = fs->curr_blkno / blk_per_grp;
+		} else {
+			bg_idx = fs->curr_blkno / blk_per_grp;
+			remainder = fs->curr_blkno % blk_per_grp;
+			if (!remainder)
+				bg_idx--;
+		}
+
+		/*
+		 * To skip completely filled block group bitmaps
+		 * Optimize the block allocation
+		 */
+		if (bg_idx >= fs->no_blkgrp)
+			goto fail;
+
+		if (bgd[bg_idx].free_blocks == 0) {
+			debug("block group %u is full. Skipping\n", bg_idx);
+			fs->curr_blkno = fs->curr_blkno + blk_per_grp;
+			fs->curr_blkno--;
+			goto restart;
+		}
+
+		if (bgd[bg_idx].bg_flags & EXT4_BG_BLOCK_UNINIT) {
+			memset(zero_buffer, '\0', fs->blksz);
+			put_ext4(((uint64_t) ((uint64_t)bgd[bg_idx].block_id *
+					(uint64_t)fs->blksz)), zero_buffer, fs->blksz);
+			memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz);
+			bgd[bg_idx].bg_flags = bgd[bg_idx].bg_flags &
+						~EXT4_BG_BLOCK_UNINIT;
+		}
+
+		if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx],
+				   bg_idx) != 0) {
+			debug("going for restart for the block no %ld %u\n",
+			      fs->curr_blkno, bg_idx);
+			goto restart;
+		}
+
+		/* journal backup */
+		if (prev_bg_bitmap_index != bg_idx) {
+			memset(journal_buffer, '\0', fs->blksz);
+			status = ext4fs_devread((lbaint_t)bgd[bg_idx].block_id
+						* fs->sect_perblk,
+						0, fs->blksz, journal_buffer);
+			if (status == 0)
+				goto fail;
+			if (ext4fs_log_journal(journal_buffer,
+						bgd[bg_idx].block_id))
+				goto fail;
+
+			prev_bg_bitmap_index = bg_idx;
+		}
+		bgd[bg_idx].free_blocks--;
+		fs->sb->free_blocks--;
+		goto success;
+	}
+success:
+	free(journal_buffer);
+	free(zero_buffer);
+
+	return fs->curr_blkno;
+fail:
+	free(journal_buffer);
+	free(zero_buffer);
+
+	return -1;
+}
+
+int ext4fs_get_new_inode_no(void)
+{
+	short i;
+	short status;
+	unsigned int ibmap_idx;
+	static int prev_inode_bitmap_index = -1;
+	unsigned int inodes_per_grp = ext4fs_root->sblock.inodes_per_group;
+	struct ext_filesystem *fs = get_fs();
+	char *journal_buffer = zalloc(fs->blksz);
+	char *zero_buffer = zalloc(fs->blksz);
+	if (!journal_buffer || !zero_buffer)
+		goto fail;
+	struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable;
+
+	if (fs->first_pass_ibmap == 0) {
+		for (i = 0; i < fs->no_blkgrp; i++) {
+			if (bgd[i].free_inodes) {
+				if (bgd[i].bg_itable_unused !=
+						bgd[i].free_inodes)
+					bgd[i].bg_itable_unused =
+						bgd[i].free_inodes;
+				if (bgd[i].bg_flags & EXT4_BG_INODE_UNINIT) {
+					put_ext4(((uint64_t)
+						  ((uint64_t)bgd[i].inode_id *
+							(uint64_t)fs->blksz)),
+						 zero_buffer, fs->blksz);
+					bgd[i].bg_flags = bgd[i].bg_flags &
+							~EXT4_BG_INODE_UNINIT;
+					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++;
+				bgd[i].free_inodes--;
+				bgd[i].bg_itable_unused--;
+				fs->sb->free_inodes--;
+				status = ext4fs_devread((lbaint_t)
+							bgd[i].inode_id *
+							fs->sect_perblk, 0,
+							fs->blksz,
+							journal_buffer);
+				if (status == 0)
+					goto fail;
+				if (ext4fs_log_journal(journal_buffer,
+							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 (bgd[ibmap_idx].bg_flags & EXT4_BG_INODE_UNINIT) {
+			memset(zero_buffer, '\0', fs->blksz);
+			put_ext4(((uint64_t) ((uint64_t)bgd[ibmap_idx].inode_id *
+					      (uint64_t)fs->blksz)), zero_buffer,
+				 fs->blksz);
+			bgd[ibmap_idx].bg_flags =
+			    bgd[ibmap_idx].bg_flags & ~EXT4_BG_INODE_UNINIT;
+			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)
+						bgd[ibmap_idx].inode_id
+						* fs->sect_perblk,
+						0, fs->blksz, journal_buffer);
+			if (status == 0)
+				goto fail;
+			if (ext4fs_log_journal(journal_buffer,
+						bgd[ibmap_idx].inode_id))
+				goto fail;
+			prev_inode_bitmap_index = ibmap_idx;
+		}
+		if (bgd[ibmap_idx].bg_itable_unused !=
+				bgd[ibmap_idx].free_inodes)
+			bgd[ibmap_idx].bg_itable_unused =
+					bgd[ibmap_idx].free_inodes;
+		bgd[ibmap_idx].free_inodes--;
+		bgd[ibmap_idx].bg_itable_unused--;
+		fs->sb->free_inodes--;
+		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 */
+	unsigned int *si_buffer = NULL;
+	unsigned int *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 = 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 = 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;
+	unsigned int *di_parent_buffer = NULL;
+	unsigned int *di_child_buff = NULL;
+	unsigned int *di_block_start_addr = NULL;
+	unsigned int *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 = 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 = 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 = 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;
+	unsigned int *ti_gp_buff = NULL;
+	unsigned int *ti_parent_buff = NULL;
+	unsigned int *ti_child_buff = NULL;
+	unsigned int *ti_gp_buff_start_addr = NULL;
+	unsigned int *ti_pbuff_start_addr = NULL;
+	unsigned int *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");
+			goto fail;
+		}
+		ti_gp_buff = zalloc(fs->blksz);
+		if (!ti_gp_buff)
+			goto fail;
+
+		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 = 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 fail;
+				}
+				ti_child_buff = zalloc(fs->blksz);
+				if (!ti_child_buff)
+					goto fail;
+
+				ti_cbuff_start_addr = ti_child_buff;
+				*ti_parent_buff = 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");
+						goto fail;
+					}
+					*ti_child_buff = 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 = ti_gp_blockno;
+	}
+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; 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] = direct_blockno;
+		debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks);
+
+		total_remaining_blocks--;
+		if (total_remaining_blocks == 0)
+			break;
+	}
+
+	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 0;
+
+		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 0;
+
+		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 0;
+	}
+}
+
+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;
+}
+
+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;
+	}
+	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;
+	}
+}
+
+int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
+				struct ext2fs_node **fnode, int *ftype)
+{
+	unsigned int fpos = 0;
+	int status;
+	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);
+		if (status < 1)
+			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);
+			if (status < 1)
+				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) {
+						free(fdiro);
+						return 0;
+					}
+					fdiro->inode_read = 1;
+				}
+				switch (type) {
+				case FILETYPE_DIRECTORY:
+					printf("<DIR> ");
+					break;
+				case FILETYPE_SYMLINK:
+					printf("<SYM> ");
+					break;
+				case FILETYPE_REG:
+					printf("      ");
+					break;
+				default:
+					printf("< ? > ");
+					break;
+				}
+				printf("%10d %s\n",
+					__le32_to_cpu(fdiro->inode.size),
+					filename);
+			}
+			free(fdiro);
+		}
+		fpos += __le16_to_cpu(dirent.direntlen);
+	}
+	return 0;
+}
+
+static char *ext4fs_read_symlink(struct ext2fs_node *node)
+{
+	char *symlink;
+	struct ext2fs_node *diro = node;
+	int status;
+
+	if (!diro->inode_read) {
+		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
+		if (status == 0)
+			return 0;
+	}
+	symlink = zalloc(__le32_to_cpu(diro->inode.size) + 1);
+	if (!symlink)
+		return 0;
+
+	if (__le32_to_cpu(diro->inode.size) <= 60) {
+		strncpy(symlink, diro->inode.b.symlink,
+			 __le32_to_cpu(diro->inode.size));
+	} else {
+		status = ext4fs_read_file(diro, 0,
+					   __le32_to_cpu(diro->inode.size),
+					   symlink);
+		if (status == 0) {
+			free(symlink);
+			return 0;
+		}
+	}
+	symlink[__le32_to_cpu(diro->inode.size)] = '\0';
+	return symlink;
+}
+
+static int ext4fs_find_file1(const char *currpath,
+			     struct ext2fs_node *currroot,
+			     struct ext2fs_node **currfound, int *foundtype)
+{
+	char fpath[strlen(currpath) + 1];
+	char *name = fpath;
+	char *next;
+	int status;
+	int type = FILETYPE_DIRECTORY;
+	struct ext2fs_node *currnode = currroot;
+	struct ext2fs_node *oldnode = currroot;
+
+	strncpy(fpath, currpath, strlen(currpath) + 1);
+
+	/* Remove all leading slashes. */
+	while (*name == '/')
+		name++;
+
+	if (!*name) {
+		*currfound = currnode;
+		return 1;
+	}
+
+	for (;;) {
+		int found;
+
+		/* Extract the actual part from the pathname. */
+		next = strchr(name, '/');
+		if (next) {
+			/* Remove all leading slashes. */
+			while (*next == '/')
+				*(next++) = '\0';
+		}
+
+		if (type != FILETYPE_DIRECTORY) {
+			ext4fs_free_node(currnode, currroot);
+			return 0;
+		}
+
+		oldnode = currnode;
+
+		/* Iterate over the directory. */
+		found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
+		if (found == 0)
+			return 0;
+
+		if (found == -1)
+			break;
+
+		/* Read in the symlink and follow it. */
+		if (type == FILETYPE_SYMLINK) {
+			char *symlink;
+
+			/* Test if the symlink does not loop. */
+			if (++symlinknest == 8) {
+				ext4fs_free_node(currnode, currroot);
+				ext4fs_free_node(oldnode, currroot);
+				return 0;
+			}
+
+			symlink = ext4fs_read_symlink(currnode);
+			ext4fs_free_node(currnode, currroot);
+
+			if (!symlink) {
+				ext4fs_free_node(oldnode, currroot);
+				return 0;
+			}
+
+			debug("Got symlink >%s<\n", symlink);
+
+			if (symlink[0] == '/') {
+				ext4fs_free_node(oldnode, currroot);
+				oldnode = &ext4fs_root->diropen;
+			}
+
+			/* Lookup the node the symlink points to. */
+			status = ext4fs_find_file1(symlink, oldnode,
+						    &currnode, &type);
+
+			free(symlink);
+
+			if (status == 0) {
+				ext4fs_free_node(oldnode, currroot);
+				return 0;
+			}
+		}
+
+		ext4fs_free_node(oldnode, currroot);
+
+		/* Found the node! */
+		if (!next || *next == '\0') {
+			*currfound = currnode;
+			*foundtype = type;
+			return 1;
+		}
+		name = next;
+	}
+	return -1;
+}
+
+int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
+	struct ext2fs_node **foundnode, int expecttype)
+{
+	int status;
+	int foundtype = FILETYPE_DIRECTORY;
+
+	symlinknest = 0;
+	if (!path)
+		return 0;
+
+	status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
+	if (status == 0)
+		return 0;
+
+	/* Check if the node that was found was of the expected type. */
+	if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
+		return 0;
+	else if ((expecttype == FILETYPE_DIRECTORY)
+		   && (foundtype != expecttype))
+		return 0;
+
+	return 1;
+}
+
+int ext4fs_open(const char *filename)
+{
+	struct ext2fs_node *fdiro = NULL;
+	int status;
+	int len;
+
+	if (ext4fs_root == NULL)
+		return -1;
+
+	ext4fs_file = NULL;
+	status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
+				  FILETYPE_REG);
+	if (status == 0)
+		goto fail;
+
+	if (!fdiro->inode_read) {
+		status = ext4fs_read_inode(fdiro->data, fdiro->ino,
+				&fdiro->inode);
+		if (status == 0)
+			goto fail;
+	}
+	len = __le32_to_cpu(fdiro->inode.size);
+	ext4fs_file = fdiro;
+
+	return len;
+fail:
+	ext4fs_free_node(fdiro, &ext4fs_root->diropen);
+
+	return -1;
+}
+
+int ext4fs_mount(unsigned part_length)
+{
+	struct ext2_data *data;
+	int status;
+	struct ext_filesystem *fs = get_fs();
+	data = zalloc(SUPERBLOCK_SIZE);
+	if (!data)
+		return 0;
+
+	/* Read the superblock. */
+	status = ext4_read_superblock((char *)&data->sblock);
+
+	if (status == 0)
+		goto fail;
+
+	/* Make sure this is an ext2 filesystem. */
+	if (__le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
+		goto fail;
+
+	if (__le32_to_cpu(data->sblock.revision_level == 0))
+		fs->inodesz = 128;
+	else
+		fs->inodesz = __le16_to_cpu(data->sblock.inode_size);
+
+	debug("EXT2 rev %d, inode_size %d\n",
+	       __le32_to_cpu(data->sblock.revision_level), fs->inodesz);
+
+	data->diropen.data = data;
+	data->diropen.ino = 2;
+	data->diropen.inode_read = 1;
+	data->inode = &data->diropen.inode;
+
+	status = ext4fs_read_inode(data, 2, data->inode);
+	if (status == 0)
+		goto fail;
+
+	ext4fs_root = data;
+
+	return 1;
+fail:
+	printf("Failed to mount ext2 filesystem...\n");
+	free(data);
+	ext4fs_root = NULL;
+
+	return 0;
+}