Under this policy, superceded Inodes are garbage, and current Inodes are not. Garbage is removed in LRU order.
This set of Inodes may be further subdivided by minimum and maximum age parameters. Anything older than the maximum age is removed regardless of the state of free disk space. Anything between the minimum and maximum age is garbage if and only if there is demand for free space (see section 9.3.1). Nothing younger than the minimum age is considered garbage.
If the maximum age is zero, the entire Inode versioning system may be disabled.