hesela.devExt4 ordered mode
Ext4 ordered mode journals metadata and orders associated file-data writes before the metadata transaction commits.
The default data=ordered mode does not put ordinary file contents in the journal or make them application-atomic. Fast commits are also scoped to ordered mode in the reviewed design. [1]
In Linux v6.12, ext4_map_blocks registers newly allocated visible blocks for ordered-data handling, excluding unwritten or explicitly zeroed mappings in that branch. This is not a global ordering guarantee for every overwrite. [2]
Relations
- related
- Ext4 data journaling, Ext4 writeback mode, Ext4 auto_da_alloc, Ext4 fast commit, Persistence ordering, Unwritten extent
Citations
- Linux v6.12: journal coverage and ordered-mode fast commits
- Linux v6.12: ext4_map_blocks ordered-data registration
Sources & caveats
- Source review scoped to Linux v6.12; not a crash experiment or certification of later kernels.