Bugfixes:

• Due to false-positive crc match it was possible to erroneously reuse pg_filenode.map file during incremental restore, which could break pg_catalog relations relying on pg_filenode.map for filenode mapping if they were subject to VACUUM FULL or REINDEX operations before backup. This is fixed now.
• A race condition between reader and writer in acquiring the backup exclusive lock is removed.
• File descriptor leak in the backup shared lock is fixed.

Improvements:

• The remote agent API is now stable across the same minor version starting with 2.4.9, which makes pg_probackup installations more robust towards version drift. Requested by Alex Ignatov.
• It is now possible to restore and validate a backup from a read-only filesystem. Requested by Mikhail Kulagin.
• Backup shared locks are now released at the process exit.