Table Of Contents:
- Use write-back cache for metadata
- async, not write-through
- Record updates with per structure relation basis, not block basis
- avoid dependency circulation
- Three flags introduced in * BSD
- ATTACHED metadata update started
- DEP_COMPLETE depdent metadata update complete
- COMPLETE data update complete
- On writing metadata, to keep metadata consistent
- roll back incomplete operations effect to the metadata 2. write metadata to DISK 3. roll forward incomplete operations effect to the metadata
- This means both DISK and memory have consistent metadata, however on DISK we may have little older metadata.
CELF Technology/Project pages
- Media:mckusick99soft.pdf - M.K.McKusick & G.R.Ganger. Soft Updates: A Technique for Eliminating Most Synchronous Writes in the Fast Filesystem. Proceedings of the FREENIX Track: 1999 USENIX Annual Technical Conference, Jun 1999.