Kent Overstreet has shipped the latest version of bcachefs-tools, the user-space code complementing the Bcachefs file-system kernel driver. There are a number of improvements present in this latest version with Overstreet remaining committed to advancing Bcachefs even with its current out-of-tree kernel status.
The bcachefs-tools 1.35 changes come down to the following noted in the release change-log:
## v1.35.0 – Mon Jan 12 2026
bcachefs_metadata_version_bucket_stripe_index
– The requirement that devices must have matched bucket sizes to be members of the same stripes has been removed.
– Stripes may be reshaped (number of blocks increased or decreased), as needed; this improves EC’s handling of device failures.
– Significantly improved evacuate, rereplicate performance on rotating disks: we now launch one thread per device being read from (i.e. every device that shared data with the device going away); each device is read from in parallel with reads across the whole device done in sorted order.
– `backpointer_scan_iter`, for improved performance for code doing backpointer -> extent walks, including but not limited to reconcile; this is quite significant on systems with metadata on rotating disk and relatively limited memory.
– The bug with reconcile where btree roots wouldn’t be processed has been fixed.
– A few bugs with reconcile’s handling of cached data have been fixed.
– The reconcile tracepoints, especially `reconcile_set_pending`, now give significantly more information.
– Reconcile now knows how to wait on copygc when a device it wants to write to is full, rather than (incorrectly) marking the extent as pending.
– Fixed several memory reclaim recursion bugs; performance under memory pressure should be improved.
– Various allocation watermark fixes; btree updates now only run with high priority watermarks when necessary. This fixes some allocator deadlocks on open bucket allocation.
– ‘encoded_extent_max` settings of 1MB and greater now work properly; previously, this could cause backpointer issues if compression was enabled.
Some nice work in this new bcachefs-tools release, especially the much-improved evaluate and rereplicate performance on rotating media along with all of the other changes.
Bcachefs-tools 1.35 can be downloaded via the project’s Git repository.
In case you missed it during the busy month of December, over in kernel space, Bcachefs is ready with its reconcile feature as the file-system’s biggest change in the past two years.
