blob: 266f54ee99858e9459dc48e1355759e221ab31d8 [file] [log] [blame]
/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <limits.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <strings.h>
#include <string.h>
#include <stdio.h>
#include <dirent.h>
#include <libgen.h>
#if defined(linux)
#include <linux/fs.h>
#elif defined(__APPLE__) && defined(__MACH__)
#include <sys/disk.h>
#endif
#include "make_ext4fs.h"
#include "ext4_utils.h"
#include "allocate.h"
#include "ext_utils.h"
#include "backed_block.h"
#include "contents.h"
#include "extent.h"
#include "indirect.h"
#include "uuid.h"
#include "jbd2.h"
#include "ext4.h"
#ifdef ANDROID
#include <private/android_filesystem_config.h>
#endif
/* TODO: Not implemented:
Allocating blocks in the same block group as the file inode
Hash or binary tree directories
Non-extent inodes
Special files: symbolic links, sockets, devices, fifos
*/
int force = 0;
struct fs_info info;
struct fs_aux_info aux_info;
/* Write a contiguous region of data blocks from a memory buffer */
static void write_data_block(void *priv, u32 block, u8 *data, int len)
{
int fd = *(int*)priv;
off_t off;
int ret;
if (block * info.block_size + len >= info.len) {
error("attempted to write block %llu past end of filesystem",
block * info.block_size + len - info.len);
return;
}
off = (off_t)block * info.block_size;
off = lseek(fd, off, SEEK_SET);
if (off < 0) {
error_errno("lseek");
return;
}
ret = write(fd, data, len);
if (ret < 0)
error_errno("write");
else if (ret < len)
error("incomplete write");
}
/* Write a contiguous region of data blocks from a file */
static void write_data_file(void *priv, u32 block, const char *file,
off_t offset, int len)
{
int fd = *(int*)priv;
off_t off;
int ret;
if (block * info.block_size + len >= info.len) {
error("attempted to write block %llu past end of filesystem",
block * info.block_size + len - info.len);
return;
}
int file_fd = open(file, O_RDONLY);
if (file_fd < 0) {
error_errno("open");
return;
}
u8 *data = mmap(NULL, len, PROT_READ, MAP_SHARED, file_fd, offset);
if (data == MAP_FAILED) {
error_errno("mmap");
close(fd);
return;
}
off = (off_t)block * info.block_size;
off = lseek(fd, off, SEEK_SET);
if (off < 0) {
error_errno("lseek");
return;
}
ret = write(fd, data, len);
if (ret < 0)
error_errno("write");
else if (ret < len)
error("incomplete write");
munmap(data, len);
close(file_fd);
}
/* Write the filesystem image to a file */
static void write_ext4_image(const char *filename)
{
int ret = 0;
int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
off_t off;
if (fd < 0) {
error_errno("open");
return;
}
off = lseek(fd, 1024, SEEK_SET);
if (off < 0) {
error_errno("lseek");
return;
}
ret = write(fd, aux_info.sb, 1024);
if (ret < 0)
error_errno("write");
else if (ret < 1024)
error("incomplete write");
off = (aux_info.first_data_block + 1) * info.block_size;
off = lseek(fd, off, SEEK_SET);
if (off < 0) {
error_errno("lseek");
return;
}
ret = write(fd, aux_info.bg_desc,
aux_info.bg_desc_blocks * info.block_size);
if (ret < 0)
error_errno("write");
else if (ret < (int)(aux_info.bg_desc_blocks * info.block_size))
error("incomplete write");
for_each_data_block(write_data_block, write_data_file, &fd);
off = info.len - 1;
off = lseek(fd, off, SEEK_SET);
if (off < 0) {
error_errno("lseek");
return;
}
ret = write(fd, "\0", 1);
if (ret < 0)
error_errno("write");
else if (ret < 1)
error("incomplete write");
close(fd);
}
/* Compute the rest of the parameters of the filesystem from the basic info */
static void ext4_create_fs_aux_info()
{
aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1;
aux_info.len_blocks = info.len / info.block_size;
aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size,
info.block_size);
aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block,
info.blocks_per_group);
aux_info.blocks_per_ind = info.block_size / sizeof(u32);
aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind;
aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind;
aux_info.bg_desc_blocks =
DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc),
info.block_size);
aux_info.bg_desc_reserve_blocks =
DIV_ROUND_UP(aux_info.groups * 1024 * sizeof(struct ext2_group_desc),
info.block_size) - aux_info.bg_desc_blocks;
if (aux_info.bg_desc_reserve_blocks > aux_info.blocks_per_ind)
aux_info.bg_desc_reserve_blocks = aux_info.blocks_per_ind;
aux_info.default_i_flags = EXT4_NOATIME_FL;
u32 last_group_size = aux_info.len_blocks % info.blocks_per_group;
u32 last_header_size = 2 + aux_info.inode_table_blocks;
if (ext4_bg_has_super_block(aux_info.groups - 1))
last_header_size += 1 + aux_info.bg_desc_blocks +
aux_info.bg_desc_reserve_blocks;
if (last_group_size > 0 && last_group_size < last_header_size) {
aux_info.groups--;
aux_info.len_blocks -= last_group_size;
}
aux_info.sb = calloc(info.block_size, 1);
if (!aux_info.sb)
critical_error_errno("calloc");
aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks);
if (!aux_info.bg_desc)
critical_error_errno("calloc");
}
void ext4_free_fs_aux_info()
{
free(aux_info.sb);
free(aux_info.bg_desc);
}
/* Fill in the superblock memory buffer based on the filesystem parameters */
static void ext4_fill_in_sb()
{
unsigned int i;
struct ext4_super_block *sb = aux_info.sb;
sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
sb->s_blocks_count_lo = aux_info.len_blocks;
sb->s_r_blocks_count_lo = 0;
sb->s_free_blocks_count_lo = 0;
sb->s_free_inodes_count = 0;
sb->s_first_data_block = aux_info.first_data_block;
sb->s_log_block_size = log_2(info.block_size / 1024);
sb->s_obso_log_frag_size = log_2(info.block_size / 1024);
sb->s_blocks_per_group = info.blocks_per_group;
sb->s_obso_frags_per_group = info.blocks_per_group;
sb->s_inodes_per_group = info.inodes_per_group;
sb->s_mtime = 0;
sb->s_wtime = 0;
sb->s_mnt_count = 0;
sb->s_max_mnt_count = 0xFFFF;
sb->s_magic = EXT4_SUPER_MAGIC;
sb->s_state = EXT4_VALID_FS;
sb->s_errors = EXT4_ERRORS_RO;
sb->s_minor_rev_level = 0;
sb->s_lastcheck = 0;
sb->s_checkinterval = 0;
sb->s_creator_os = EXT4_OS_LINUX;
sb->s_rev_level = EXT4_DYNAMIC_REV;
sb->s_def_resuid = EXT4_DEF_RESUID;
sb->s_def_resgid = EXT4_DEF_RESGID;
sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
sb->s_inode_size = info.inode_size;
sb->s_block_group_nr = 0;
sb->s_feature_compat = info.feat_compat;
sb->s_feature_incompat = info.feat_incompat;
sb->s_feature_ro_compat = info.feat_ro_compat;
generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid);
memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name));
memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
sb->s_algorithm_usage_bitmap = 0;
sb->s_reserved_gdt_blocks = aux_info.bg_desc_reserve_blocks;
sb->s_prealloc_blocks = 0;
sb->s_prealloc_dir_blocks = 0;
//memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
sb->s_journal_inum = EXT4_JOURNAL_INO;
sb->s_journal_dev = 0;
sb->s_last_orphan = 0;
sb->s_hash_seed[0] = 0; /* FIXME */
sb->s_def_hash_version = DX_HASH_TEA;
sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS;
sb->s_desc_size = sizeof(struct ext2_group_desc);
sb->s_default_mount_opts = 0; /* FIXME */
sb->s_first_meta_bg = 0;
sb->s_mkfs_time = 0;
//sb->s_jnl_blocks[17]; /* FIXME */
sb->s_blocks_count_hi = aux_info.len_blocks >> 32;
sb->s_r_blocks_count_hi = 0;
sb->s_free_blocks_count_hi = 0;
sb->s_min_extra_isize = sizeof(struct ext4_inode)
- EXT4_GOOD_OLD_INODE_SIZE;
sb->s_want_extra_isize = sizeof(struct ext4_inode)
- EXT4_GOOD_OLD_INODE_SIZE;
sb->s_flags = 0;
sb->s_raid_stride = 0;
sb->s_mmp_interval = 0;
sb->s_mmp_block = 0;
sb->s_raid_stripe_width = 0;
sb->s_log_groups_per_flex = 0;
sb->s_kbytes_written = 0;
for (i = 0; i < aux_info.groups; i++) {
u64 group_start_block = aux_info.first_data_block + i
* info.blocks_per_group;
u32 header_size = 0;
if (ext4_bg_has_super_block(i)) {
if (i != 0) {
queue_data_block((u8 *)sb, info.block_size, group_start_block);
queue_data_block((u8 *)aux_info.bg_desc,
aux_info.bg_desc_blocks * info.block_size,
group_start_block + 1);
}
header_size = 1 + aux_info.bg_desc_blocks + aux_info.bg_desc_reserve_blocks;
}
aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size;
aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1;
aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2;
aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group;
aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group;
aux_info.bg_desc[i].bg_used_dirs_count = 0;
}
}
static void ext4_create_resize_inode()
{
struct block_allocation *reserve_inode_alloc = create_allocation();
u32 reserve_inode_len = 0;
unsigned int i;
struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO);
if (inode == NULL) {
error("failed to get resize inode");
return;
}
for (i = 0; i < aux_info.groups; i++) {
if (ext4_bg_has_super_block(i)) {
u64 group_start_block = aux_info.first_data_block + i *
info.blocks_per_group;
u32 reserved_block_start = group_start_block + 1 +
aux_info.bg_desc_blocks;
u32 reserved_block_len = aux_info.bg_desc_reserve_blocks;
append_region(reserve_inode_alloc, reserved_block_start,
reserved_block_len, i);
reserve_inode_len += reserved_block_len;
}
}
inode_attach_resize(inode, reserve_inode_alloc);
inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
inode->i_links_count = 1;
free_alloc(reserve_inode_alloc);
}
/* Allocate the blocks to hold a journal inode and connect them to the
reserved journal inode */
static void ext4_create_journal_inode()
{
struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO);
if (inode == NULL) {
error("failed to get journal inode");
return;
}
u8 *journal_data = inode_allocate_data_extents(inode,
info.journal_blocks * info.block_size,
info.block_size);
if (!journal_data) {
error("failed to allocate extents for journal data");
return;
}
inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
inode->i_links_count = 1;
journal_superblock_t *jsb = (journal_superblock_t *)journal_data;
jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
jsb->s_blocksize = htonl(info.block_size);
jsb->s_maxlen = htonl(info.journal_blocks);
jsb->s_nr_users = htonl(1);
jsb->s_first = htonl(1);
jsb->s_sequence = htonl(1);
memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block));
}
/* Update the number of free blocks and inodes in the filesystem and in each
block group */
static void ext4_update_free()
{
unsigned int i;
for (i = 0; i < aux_info.groups; i++) {
u32 bg_free_blocks = get_free_blocks(i);
u32 bg_free_inodes = get_free_inodes(i);
aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks;
aux_info.sb->s_free_blocks_count_lo += bg_free_blocks;
aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes;
aux_info.sb->s_free_inodes_count += bg_free_inodes;
aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i);
}
}
static int filter_dot(const struct dirent *d)
{
return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
}
static u32 build_default_directory_structure()
{
u32 inode;
u32 root_inode;
struct dentry dentries = {
.filename = "lost+found",
.file_type = EXT4_FT_DIR,
.mode = S_IRWXU,
.uid = 0,
.gid = 0
};
root_inode = make_directory(0, 1, &dentries, 1);
inode = make_directory(root_inode, 0, NULL, 0);
*dentries.inode = inode;
return root_inode;
}
/* Read a local directory and create the same tree in the generated filesystem.
Calls itself recursively with each directory in the given directory */
static u32 build_directory_structure(const char *full_path, const char *dir_path,
u32 dir_inode, int android)
{
int entries = 0;
struct dentry *dentries;
struct dirent **namelist;
struct stat stat;
int ret;
int i;
u32 inode;
u32 entry_inode;
u32 dirs = 0;
entries = scandir(full_path, &namelist, filter_dot, alphasort);
if (entries < 0) {
error_errno("scandir");
return EXT4_ALLOCATE_FAILED;
}
dentries = calloc(entries, sizeof(struct dentry));
if (dentries == NULL)
critical_error_errno("malloc");
for (i = 0; i < entries; i++) {
dentries[i].filename = strdup(namelist[i]->d_name);
if (dentries[i].filename == NULL)
critical_error_errno("strdup");
asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name);
asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name);
free(namelist[i]);
ret = lstat(dentries[i].full_path, &stat);
if (ret < 0) {
error_errno("lstat");
i--;
entries--;
continue;
}
dentries[i].size = stat.st_size;
dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
if (android) {
#ifdef ANDROID
unsigned int mode = 0;
unsigned int uid = 0;
unsigned int gid = 0;
int dir = S_ISDIR(stat.st_mode);
fs_config(dentries[i].path, dir, &uid, &gid, &mode);
dentries[i].mode = mode;
dentries[i].uid = uid;
dentries[i].gid = gid;
#else
error("can't set android permissions - built without android support");
#endif
}
if (S_ISREG(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_REG_FILE;
} else if (S_ISDIR(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_DIR;
dirs++;
} else if (S_ISCHR(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_CHRDEV;
} else if (S_ISBLK(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_BLKDEV;
} else if (S_ISFIFO(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_FIFO;
} else if (S_ISSOCK(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_SOCK;
} else if (S_ISLNK(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_SYMLINK;
dentries[i].link = calloc(info.block_size, 1);
readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
} else {
error("unknown file type on %s", dentries[i].path);
i--;
entries--;
}
}
free(namelist);
inode = make_directory(dir_inode, entries, dentries, dirs);
for (i = 0; i < entries; i++) {
if (dentries[i].file_type == EXT4_FT_REG_FILE) {
entry_inode = make_file(dentries[i].full_path, dentries[i].size);
} else if (dentries[i].file_type == EXT4_FT_DIR) {
entry_inode = build_directory_structure(dentries[i].full_path,
dentries[i].path, inode, android);
} else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
entry_inode = make_link(dentries[i].full_path, dentries[i].link);
} else {
error("unknown file type on %s", dentries[i].path);
entry_inode = 0;
}
*dentries[i].inode = entry_inode;
ret = inode_set_permissions(entry_inode, dentries[i].mode,
dentries[i].uid, dentries[i].gid);
if (ret)
error("failed to set permissions on %s\n", dentries[i].path);
free(dentries[i].path);
free(dentries[i].full_path);
free(dentries[i].link);
free((void *)dentries[i].filename);
}
free(dentries);
return inode;
}
static u32 compute_block_size()
{
return 4096;
}
static u32 compute_blocks_per_group()
{
return info.block_size * 8;
}
static u32 compute_inodes()
{
return DIV_ROUND_UP(info.len, info.block_size) / 4;
}
static u32 compute_inodes_per_group()
{
u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
return DIV_ROUND_UP(info.inodes, block_groups);
}
static u64 get_block_device_size(const char *filename)
{
int fd = open(filename, O_RDONLY);
u64 size = 0;
int ret;
if (fd < 0)
return 0;
#if defined(linux)
ret = ioctl(fd, BLKGETSIZE64, &size);
#elif defined(__APPLE__) && defined(__MACH__)
ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size);
#else
return 0;
#endif
close(fd);
if (ret)
return 0;
return size;
}
static u64 get_file_size(const char *filename)
{
struct stat buf;
int ret;
ret = stat(filename, &buf);
if (ret)
return 0;
if (S_ISREG(buf.st_mode))
return buf.st_size;
else if (S_ISBLK(buf.st_mode))
return get_block_device_size(filename);
else
return 0;
}
static void usage(char *path)
{
fprintf(stderr, "%s [ -l <len> ] [ -j <journal size> ] [ -b <block_size> ]\n", basename(path));
fprintf(stderr, " [ -g <blocks per group> ] [ -i <inodes> ] [ -I <inode size> ]\n");
fprintf(stderr, " [ -L <label> ] [ -f ] [ -a <android mountpoint> ]\n");
fprintf(stderr, " <filename> [<directory>]\n");
}
static u64 parse_num(const char *arg)
{
char *endptr;
u64 num = strtoull(arg, &endptr, 10);
if (*endptr == 'k' || *endptr == 'K')
num *= 1024LL;
else if (*endptr == 'm' || *endptr == 'M')
num *= 1024LL * 1024LL;
else if (*endptr == 'g' || *endptr == 'G')
num *= 1024LL * 1024LL * 1024LL;
return num;
}
int main(int argc, char **argv)
{
int opt;
const char *filename = NULL;
const char *directory = NULL;
char *mountpoint = "";
int android = 0;
u32 root_inode_num;
u16 root_mode;
while ((opt = getopt(argc, argv, "l:j:b:g:i:I:L:a:f")) != -1) {
switch (opt) {
case 'l':
info.len = parse_num(optarg);
break;
case 'j':
info.journal_blocks = parse_num(optarg);
break;
case 'b':
info.block_size = parse_num(optarg);
break;
case 'g':
info.blocks_per_group = parse_num(optarg);
break;
case 'i':
info.inodes = parse_num(optarg);
break;
case 'I':
info.inode_size = parse_num(optarg);
break;
case 'L':
info.label = optarg;
break;
case 'f':
force = 1;
break;
case 'a':
android = 1;
mountpoint = optarg;
break;
default: /* '?' */
usage(argv[0]);
exit(EXIT_FAILURE);
}
}
if (optind >= argc) {
fprintf(stderr, "Expected filename after options\n");
usage(argv[0]);
exit(EXIT_FAILURE);
}
filename = argv[optind++];
if (optind < argc)
directory = argv[optind++];
if (optind < argc) {
fprintf(stderr, "Unexpected argument: %s\n", argv[optind]);
usage(argv[0]);
exit(EXIT_FAILURE);
}
if (info.len == 0)
info.len = get_file_size(filename);
if (info.len <= 0) {
fprintf(stderr, "Need size of filesystem\n");
usage(argv[0]);
exit(EXIT_FAILURE);
}
if (info.journal_blocks > 0)
info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
if (info.block_size <= 0)
info.block_size = compute_block_size();
if (info.blocks_per_group <= 0)
info.blocks_per_group = compute_blocks_per_group();
if (info.inodes <= 0)
info.inodes = compute_inodes();
if (info.inode_size <= 0)
info.inode_size = 256;
if (info.label == NULL)
info.label = "";
info.inodes_per_group = compute_inodes_per_group();
info.feat_compat |=
EXT4_FEATURE_COMPAT_RESIZE_INODE;
info.feat_ro_compat |=
EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
info.feat_incompat |=
EXT4_FEATURE_INCOMPAT_EXTENTS |
EXT4_FEATURE_INCOMPAT_FILETYPE;
printf("Creating filesystem with parameters:\n");
printf(" Size: %llu\n", info.len);
printf(" Block size: %d\n", info.block_size);
printf(" Blocks per group: %d\n", info.blocks_per_group);
printf(" Inodes per group: %d\n", info.inodes_per_group);
printf(" Inode size: %d\n", info.inode_size);
printf(" Label: %s\n", info.label);
ext4_create_fs_aux_info();
printf(" Blocks: %llu\n", aux_info.len_blocks);
printf(" Block groups: %d\n", aux_info.groups);
printf(" Reserved block group size: %d\n", aux_info.bg_desc_reserve_blocks);
block_allocator_init();
ext4_fill_in_sb();
if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
error("failed to reserve first 10 inodes");
if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
ext4_create_journal_inode();
if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
ext4_create_resize_inode();
if (directory)
root_inode_num = build_directory_structure(directory, mountpoint, 0, android);
else
root_inode_num = build_default_directory_structure();
root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
inode_set_permissions(root_inode_num, root_mode, 0, 0);
ext4_update_free();
printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
aux_info.sb->s_inodes_count,
aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
aux_info.sb->s_blocks_count_lo);
write_ext4_image(filename);
return 0;
}