1. A method of maintaining a data structure configured to associate storage blocks with corresponding file system objects, the method comprising: receiving a storage request from a storage client, wherein the storage request includes a reference to at least one storage block in a file system; identifying at least a first file system object associated with the referenced storage block based on a first data structure that associates storage blocks with file system objects, wherein the first data structure is different from a second data structure that is used by the file system to associate storage blocks with file system objects; monitoring first file system metadata in the file system associated with the first file system object to detect at least one change to the first file system metadata in response to the storage request; in response to the detection of a change in the first file system metadata, updating a first portion of the first data structure associating the referenced storage block with the first file system object, wherein the change in the first file system metadata indicates a deletion of an existing file system object in the file system, and wherein updating the first portion of the first data structure comprises: scanning the second data structure to identify a first set of storage blocks associated with the first file system object, wherein the first set of storage blocks includes the referenced storage block; removing the first file system object from the first data structure; and removing an association of the first file system object with the first set of storage blocks from the first data structure; and identifying a second file system object for prefetching based on the first file system object.