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 = 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);
}
/* Compute the rest of the parameters of the filesystem from the basic info */
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.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 +
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);
/* Alloc an array to hold the pointers to the backup superblocks */
aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *));
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");
aux_info.xattrs = NULL;
}
/* Fill in the superblock memory buffer based on the filesystem parameters */
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 = 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) {
aux_info.backup_sb[i] = calloc(info.block_size, 1);
memcpy(aux_info.backup_sb[i], sb, info.block_size);
/* Update the block group nr of this backup superblock */
aux_info.backup_sb[i]->s_block_group_nr = i;
queue_data_block((u8 *)aux_info.backup_sb[i],
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 + 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;
}
}