int do_mkfs()

in fs/extfs/mkfs.cpp [52:134]
69 lines of code
9 McCabe index (conditional complexity)

int do_mkfs(io_manager manager, size_t size, char *uuid) {
    int blocksize = 4096;
    blk64_t blocks_count = size / blocksize;
    int inode_ratio = 16384;
    int inode_size = 256;
    double reserved_ratio = 0.05;

    struct ext2_super_block fs_param;
    memset(&fs_param, 0, sizeof(struct ext2_super_block));
    fs_param.s_rev_level = 1;

    ext2fs_set_feature_64bit(&fs_param);
    ext2fs_set_feature_sparse_super(&fs_param);
    ext2fs_set_feature_sparse_super2(&fs_param);
    ext2fs_set_feature_filetype(&fs_param);
    ext2fs_set_feature_resize_inode(&fs_param);
    ext2fs_set_feature_dir_index(&fs_param);
    ext2fs_set_feature_xattr(&fs_param);
    ext2fs_set_feature_dir_nlink(&fs_param);
    ext2fs_set_feature_large_file(&fs_param);
    ext2fs_set_feature_huge_file(&fs_param);
    ext2fs_set_feature_flex_bg(&fs_param);
    ext2fs_set_feature_extents(&fs_param);
    ext2fs_set_feature_extra_isize(&fs_param);

    fs_param.s_log_cluster_size = fs_param.s_log_block_size = 2;
    fs_param.s_desc_size = EXT2_MIN_DESC_SIZE_64BIT;
    fs_param.s_log_groups_per_flex = 0;
    fs_param.s_inode_size = inode_size;

    ext2fs_blocks_count_set(&fs_param, blocks_count);
    unsigned long long n = ext2fs_blocks_count(&fs_param) * blocksize / inode_ratio;
    fs_param.s_inodes_count = (n > UINT_MAX) ? UINT_MAX : n;

    ext2fs_r_blocks_count_set(&fs_param, reserved_ratio * ext2fs_blocks_count(&fs_param));
    fs_param.s_backup_bgs[0] = 1;
    fs_param.s_backup_bgs[1] = ~0;

    ext2_filsys fs;
    // init superblock
    errcode_t ret = ext2fs_initialize("virtual-dev", 0, &fs_param, manager, &fs);
    if (ret) {
        LOG_ERRNO_RETURN(0, -1, "error while setting up superblock ", VALUE(ret));
    }

    uuid4_parse(uuid, (char*)(fs->super->s_uuid));
    uuid4_parse(uuid, (char*)(fs_param.s_hash_seed));
    fs->super->s_kbytes_written = 1;
    fs->super->s_def_hash_version = EXT2_HASH_HALF_MD4;
    fs->super->s_max_mnt_count = -1;
    fs->stride = fs->super->s_raid_stride;
    // alloc tables
    ret = ext2fs_allocate_tables(fs);
    if (ret) {
        LOG_ERRNO_RETURN(0, -1, "error while allocating tables ", VALUE(ret));
    }
    // create root dir
    ret = ext2fs_mkdir(fs, EXT2_ROOT_INO, EXT2_ROOT_INO, 0);
    if (ret) {
        LOG_ERRNO_RETURN(0, -1, "error make root dir ", VALUE(ret));
    }
    // mkdir for lost+found
    ret = mkdir_lost_found(fs);
    if (ret) {
        return ret;
    }
    // reserve inodes
    ext2fs_inode_alloc_stats2(fs, EXT2_BAD_INO, +1, 0);
    for (ext2_ino_t i = EXT2_ROOT_INO + 1; i < EXT2_FIRST_INODE(fs->super); i++)
        ext2fs_inode_alloc_stats2(fs, i, +1, 0);
    ext2fs_mark_ib_dirty(fs);
    // create resize inode
    ret = ext2fs_create_resize_inode(fs);
    if (ret) {
        LOG_ERRNO_RETURN(0, -1, "error creating resize inode ", VALUE(ret));
    }

    ret = ext2fs_close_free(&fs);
    if (ret) {
        LOG_ERRNO_RETURN(0, -1, "error closing fs ", VALUE(ret));
    }
    return 0;
}