11cbb2f275
requests in parallel. + Add kern.geom.mirror.sync_requests tunable which defines how many parallel I/O requests should be used. + Retire kern.geom.mirror.reqs_per_sync and kern.geom.mirror.syncs_per_sec sysctls. - Fix race between regular and synchronization requests. - Reimplement mirror's data synchronization - do not use the topology lock for this purpose, as it may case deadlocks. - Stop synchronization from pre-sync hook. - Fix some other minor issues. MFC after: 3 days