diff --git a/ext/blockgroup.cpp b/ext/blockgroup.cpp
index 36a118bf..f600cd43 100644
--- a/ext/blockgroup.cpp
+++ b/ext/blockgroup.cpp
@@ -92,6 +92,7 @@ uint32_t BlockGroup::AllocateBlock()
 		uint32_t chunk_offset = block_alloc_chunk * num_chunk_bits;
 		uint8_t* chunk_bits = block_bitmap_chunk->block_data;
 		size_t num_bits = last ? num_blocks - chunk_offset : num_chunk_bits;
+		// TODO: This can be made faster by caching if previous bits were set.
 		for ( ; block_bitmap_chunk_i < num_bits; block_bitmap_chunk_i++ )
 			if ( !checkbit(chunk_bits, block_bitmap_chunk_i) )
 			{
@@ -133,6 +134,7 @@ uint32_t BlockGroup::AllocateInode()
 		uint32_t chunk_offset = inode_alloc_chunk * num_chunk_bits;
 		uint8_t* chunk_bits = inode_bitmap_chunk->block_data;
 		size_t num_bits = last ? num_inodes - chunk_offset : num_chunk_bits;
+		// TODO: This can be made faster by caching if previous bits were set.
 		for ( ; inode_bitmap_chunk_i < num_bits; inode_bitmap_chunk_i++ )
 			if ( !checkbit(chunk_bits, inode_bitmap_chunk_i) )
 			{
diff --git a/ext/filesystem.cpp b/ext/filesystem.cpp
index a83964d9..bff163cc 100644
--- a/ext/filesystem.cpp
+++ b/ext/filesystem.cpp
@@ -95,6 +95,8 @@ void Filesystem::Sync()
 {
 	while ( dirty_inode )
 		dirty_inode->Sync();
+	// TODO: This can be made faster by maintaining a linked list of dirty block
+	//       groups.
 	for ( size_t i = 0; i < num_groups; i++ )
 		if ( block_groups && block_groups[i] )
 			block_groups[i]->Sync();
@@ -174,9 +176,15 @@ uint32_t Filesystem::AllocateBlock(BlockGroup* preferred)
 	if ( preferred )
 		if ( uint32_t block_id = preferred->AllocateBlock() )
 			return block_id;
+	// TODO: This can be made faster by maintaining a linked list of block
+	//       groups that definitely have free blocks.
 	for ( uint32_t group_id = 0; group_id < num_groups; group_id++ )
 		if ( uint32_t block_id = GetBlockGroup(group_id)->AllocateBlock() )
 			return block_id;
+	// TODO: This case should only be fit in the event of corruption. We should
+	//       rebuild all these values upon filesystem mount instead so we know
+	//       this can't happen. That also allows us to make the linked list
+	//       requested above.
 	sb->s_free_blocks_count--;
 	Dirty();
 	return errno = ENOSPC, 0;
@@ -189,9 +197,15 @@ uint32_t Filesystem::AllocateInode(BlockGroup* preferred)
 	if ( preferred )
 		if ( uint32_t inode_id = preferred->AllocateInode() )
 			return inode_id;
+	// TODO: This can be made faster by maintaining a linked list of block
+	//       groups that definitely have free inodes.
 	for ( uint32_t group_id = 0; group_id < num_groups; group_id++ )
 		if ( uint32_t inode_id = GetBlockGroup(group_id)->AllocateInode() )
 			return inode_id;
+	// TODO: This case should only be fit in the event of corruption. We should
+	//       rebuild all these values upon filesystem mount instead so we know
+	//       this can't happen. That also allows us to make the linked list
+	//       requested above.
 	sb->s_free_inodes_count--;
 	Dirty();
 	return errno = ENOSPC, 0;