Add inode space usage statistics tracking to blockstore

src/blockstore.cpp

@@ -43,6 +43,11 @@ std::unordered_map<object_id, uint64_t> & blockstore_t::get_unstable_writes()
     return impl->unstable_writes;
 }
 
+std::map<uint64_t, int64_t> & blockstore_t::get_inode_space_stats()
+{
+    return impl->inode_space_stats;
+}
+
 uint32_t blockstore_t::get_block_size()
 {
     return impl->get_block_size();