Patent ID: 8924364

Claim:
A method of managing usage metrics of quota trees in a file system, comprising: accessing an inode (index node) table of the file system from memory, the inode table representing multiple inodes of the file system and respective usage attributes of the inodes and indicating, for a set of the inodes in the inode table, a quota tree ID, the quota tree ID identifying a particular quota tree to which each of the set of inodes belongs; and calculating, via a set of processors coupled to the memory, a usage metric for the quota tree based on the usage attributes of the inodes in the set of inodes of the inode table; accessing a quota tree database that associates the quota tree with a previously stored usage metric; and updating the previously stored usage metric in the quota tree database with the calculated usage metric, wherein the respective usage attributes of the inodes relate to an amount of space that objects represented by the inodes in the inode table occupy in memory, and wherein the calculated usage metric relates to an amount of space that all objects represented in the set of inodes together occupy in the memory, wherein the inode table further indicates, for additional sets of inodes, additional respective quota tree IDs identifying quota trees to which each of the additional sets of inodes belongs, wherein the quota tree database associates each of the additional quota trees with a previously stored usage metric, and wherein the method further comprises: calculating a usage metric for each of the additional quota trees based on the usage attributes represented by the inodes in each of the respective additional sets of inodes in the inode table; and updating each previously stored usage metric in the quota tree database with the respective calculated usage metric, wherein calculating the usage metric of the quota tree and calculating the usage metrics of each of the additional quota trees are performed with a single accessing of the inode table.