Hello, this patch series implements promised cleanup of ext4 data=journal writeback path. That way we can get rid of last remnants of old support for .writepage callback and mostly unify this writeback path with standard data handling modes. We also update some of the stale comments regarding data=journal mode along the way. Note that patch 3 (ext4: Mark page for delayed dirtying only if it is pinned) currently breaks somewhat the data=journal guarantees if mapped page cache is used as a buffer for direct IO read because that path does not pin pages yet (David Howels is working on it). But I figured this is not a huge deal for a cornercase usecase of a cornercase configuration and keeping marking page for delayed dirtying unconditionally is problematic as checkpointing dirties the page as well so it is effectively permanently added to the journal. It was problematic already in the past and happened to work only by luck. Honza
