---
fixes:
  - >
    Improvements in key parts of the consistency engine

    - Optimized the common case for hashing filesystem trees, thus
      eliminating a lot of extraneous disk I/O.

    - Updated the `hashes.pkl` file format to include timestamp information
      for race detection. Also simplified hashing logic to prevent race
      conditions and optimize for the common case.

    Upgrade Impact: If you upgrade and roll back, you must delete all
    `hashes.pkl` files.

  - >
    If using erasure coding with ISA-L in rs_vand mode and 5 or more parity
    fragments, Swift will emit a warning. This is a configuration that is
    known to harm data durability. In a future release, this warning will be
    upgraded to an error unless the policy is marked as deprecated. All data
    in an erasure code storage policy using isa_l_rs_vand with 5 or more
    parity should be migrated as soon as possible. Please see
    https://bugs.launchpad.net/swift/+bug/1639691 for more information.

  - >
    Fixed a bug where the ring builder would not allow removal of a device
    when min_part_seconds_left was greater than zero.

  - >
    PUT subrequests generated from a client-side COPY will now properly log
    the SSC (server-side copy) Swift source field. See
    https://docs.openstack.org/developer/swift/logs.html#swift-source for
    more information.

  - >
    Rings with min_part_hours set to zero will now only move one partition
    replica per rebalance, thus matching behavior when min_part_hours is
    greater than zero.

  - >
    Correctly send 412 Precondition Failed if a user sends an
    invalid copy destination. Previously Swift would send a 500
    Internal Server Error.

  - >
    Fixed error where a container drive error resulted in double space
    usage on rest drives. When drive with container or account database
    is unmounted, the bug would create handoff replicas on all remaining
    drives, increasing the drive space used and filling the cluster.

  - >
    Account and container databases will now be quarantined if the
    database schema has been corrupted.

  - >
    Ensure update of the container by object-updater, removing a rare
    possibility that objects would never be added to a container listing.

  - Fixed some minor test compatibility issues.

  - Updated docs to reference appropriate ports.