A write request is received to write a data block having a logical block address to a nonvolatile storage device. The method includes writing a value of the data block to the nonvolatile storage device. The writing includes locating a position in a tree-based data structure that includes first and second nodes. The first node is configured to store a first set of data blocks having logical block addresses in a first numerical range, and the second node is configured to store a second set of data blocks having logical block addresses in a second numerical range. The position is located in the first node or the second node depending on the value of the logical block address. The writing includes storing the value of the data block in the position in the tree-based data structure.