Systems and methods for, among other things, providing a storage system which allows for efficient tracking of in-use storage disk blocks using “sharing nodes”. Disk blocks are a result of low-level formatting, which breaks up the total storage capacity into a set number of blocks. High-level formatting of the disk creates the file system, and part of the file system may create metadata known as inodes, and associate an inode with each file, such that an inode tracks the disk blocks in use by that file, pointing from the file to a set of blocks. An S-node generator creates another type of metadata, complementary to an inode, known as an S-node data structure, such that an S-node data structure is associated with a block, and tracks the set of inodes using the block, pointing from the disk blocks to inodes.