DateiinodeCache

DateiinodeCache is a software component in a computer system’s file management stack that caches inode metadata to speed up file system operations. By storing frequently accessed inode information in memory, it reduces the need to read inode structures from stable storage, thereby lowering latency for metadata-intensive tasks such as stat, access, and directory traversal.

The cache typically maintains a mapping from inode identifiers to inode metadata. Common data structures include hash tables or tree-based structures, paired with freshness information and a dirty flag. Inodes may be cached in memory per file system instance, with eviction governed by policies such as least recently used (LRU) or configurable size limits. Inodes in the cache usually contain metadata fields like permissions, ownership, timestamps, size, block pointers, and flags needed by the file system to service requests without consulting disk.

Operation involves checking the cache on metadata access. A cache hit returns the cached inode data, while a miss triggers a read of the inode from disk and subsequent insertion into the cache. Updates to inode fields mark the corresponding cache entry as dirty; the system later flushes dirty inodes back to storage, either on a timer, during eviction, or as part of a journaling/commit process to maintain data integrity. Synchronization mechanisms ensure coherence with ongoing file system operations and with directory updates.

Performance and reliability considerations include memory usage, cache hit rate, and the impact on write-back latency. The DateiinodeCache is often designed to work alongside other caching layers such as the directory cache and the page cache, and may be tuned per workload or storage device. See also: inode, file system cache, directory cache.