hammer_blockmap_layer2
struct hammer_blockmap_layer2 layer2;
struct hammer_blockmap_layer2 layer2;
struct hammer_blockmap_layer2 layer2;
assert(sizeof(struct hammer_blockmap_layer2) == 16);
offsetof(struct hammer_blockmap_layer2, entry_crc)
((int)(HAMMER_BIGBLOCK_SIZE / sizeof(struct hammer_blockmap_layer2)))
sizeof(struct hammer_blockmap_layer2))