Function bf_init_onload

tinyemu/block_net.c:439–531

}

static void bf_init_onload(void *opaque, int err, void *data, size_t size)
{
    BlockDevice *bs = opaque;
    BlockDeviceHTTP *bf = bs->opaque;
    int block_size_kb, block_num;
    JSONValue cfg, array;
    
    if (err < 0) {
        fprintf(stderr, "Could not load block device file (err=%d)\n", -err);
        exit(1);
    }

    /* parse the disk image info */
    cfg = json_parse_value_len(data, size);
    if (json_is_error(cfg)) {
        vm_error("error: %s\n", json_get_error(cfg));
    config_error:
        json_free(cfg);
        exit(1);
    }

    if (vm_get_int(cfg, "block_size", &block_size_kb) < 0)
        goto config_error;
    bf->block_size = block_size_kb * 2;
    if (bf->block_size <= 0 ||
        (bf->block_size & (bf->block_size - 1)) != 0) {
        vm_error("invalid block_size\n");
        goto config_error;
    }
    if (vm_get_int(cfg, "n_block", &bf->nb_blocks) < 0)
        goto config_error;
    if (bf->nb_blocks <= 0) {
        vm_error("invalid n_block\n");
        goto config_error;
    }

    bf->nb_sectors = bf->block_size * (uint64_t)bf->nb_blocks;
    bf->n_cached_blocks = 0;
    bf->n_cached_blocks_max = max_int(1, bf->max_cache_size_kb / block_size_kb);
    bf->cur_block_num = -1; /* no request in progress */
    
    bf->sectors_per_cluster = 8; /* 4 KB */
    bf->n_clusters = (bf->nb_sectors + bf->sectors_per_cluster - 1) / bf->sectors_per_cluster;
    bf->clusters = mallocz(sizeof(bf->clusters[0]) * bf->n_clusters);

    if (vm_get_int_opt(cfg, "prefetch_group_len",
                       &bf->prefetch_group_len, 1) < 0)
        goto config_error;
    if (bf->prefetch_group_len > PREFETCH_GROUP_LEN_MAX) {
        vm_error("prefetch_group_len is too large");
        goto config_error;
    }
    
    array = json_object_get(cfg, "prefetch");
    if (!json_is_undefined(array)) {
        int idx, prefetch_len, l, i;
        JSONValue el;
        int tab_block_num[PREFETCH_GROUP_LEN_MAX];