cluster-cache: fix put() not allocating space for a cluster in on-disk storage

src/cluster-cache.c

@@ -185,6 +185,30 @@ enum ec3_status cluster_cache_get(
 	return EC3_SUCCESS;
 }
 
+static enum ec3_status alloc_ondisk_cluster(
+	struct cluster_cache *cache,
+	size_t *offset)
+{
+	char buf[1024] = {0};
+
+	size_t pos;
+	b_file_size(cache->c_storage, &pos);
+	b_file_seek(cache->c_storage, 0, B_SEEK_END);
+
+	for (size_t i = 0; i < cache->c_cluster_size; i += sizeof buf) {
+		size_t nr_written = 0;
+		b_file_write(
+			cache->c_storage,
+			B_OFFSET_CURRENT,
+			sizeof buf,
+			buf,
+			&nr_written);
+	}
+
+	*offset = pos;
+	return EC3_SUCCESS;
+}
+
 enum ec3_status cluster_cache_put(
 	struct cluster_cache *cache,
 	size_t cluster_id,
@@ -210,7 +234,7 @@ enum ec3_status cluster_cache_put(
 		entry->e_length = len;
 
 		if (cache->c_storage) {
-			b_file_size(cache->c_storage, &entry->e_storage_offset);
+			alloc_ondisk_cluster(cache, &entry->e_storage_offset);
 		}
 
 		put_cluster(&cache->c_entries, entry);