Journaling file systems (JFS) provide robust storage. Green Hills Software's Partitioning JFS (PJFS) moves journaling into the embedded space. It works with the Green Hills Integrity real-time operating system. As a result, partitions can take advantage of Integrity's multiple independent levels of security (MILS) architecture (see the figure). This can prevent security breaches, such as when a higher-security application tries to write data to a lower-security file partition.
Unlike many journaling file systems that only protect meta data, PJFS protects file data from loss or corruption. Likewise, it can set up caching and journaling services per application so higher-security data never gets exposed inadvertently.
PJFS uses an extended POSIX interface that allows asynchronous reads and writes. It also supports an ARINC 653 interface. PJFS works with flash and hard-disk storage devices, and it includes Green Hills' flash-memory wear-leveling support.
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