Multilevel Directories

Multilevel directories (MLDs) enable a program that runs at different sensitivity labels to use a common directory and access files at the sensitivity label at which the process is currently running. An MLD contains only single-level directories (SLDs), and each SLD stores files at the sensitivity label of the SLD. Within one MLD, several files with the same name can be stored in different SLDs. Each instance of the same file contains data appropriate to the sensitivity label of the SLD where it is stored. This is called polyinstantiation of directories and files. Chapter 7, Multilevel Directories describes programming interfaces that do the following:

• Get single-level or multilevel directory names.

• Get attribute information for a single-level or multilevel directory.

• Using single-level or multilevel directory names in system calls.