• Iustin Pop's avatar
    Fix DRBD8 diskless assembling · bf25af3b
    Iustin Pop authored
    The algorithm for attaching to existing DRBD devices is not trivial. It
    has four alternatives, and there is a bug in the last one when we have
    diskless devices.
    
    The last case (local disk info matches but remote/network configuration
    doesn't match) we disconnect from the network and reattach with the
    correct info. We do this because correct local device has higher
    priority than remote device.
    
    However, the test we use (self._MatchesLocal) can succeed in two cases:
      - we have a disk and it's the same as the one attached
      - we don't have a disk and the drbd is in diskless mode
    
    But this creates problems for the fourth case as when we already have
    one diskless DRBD, activating then next one will do:
      - _MatchesLocal? yes, because both config data and system have no
        disks (with the effect that all diskless devices are identical)
      - _MatchesRemote? no, because this disk is configured to its current
        remote peer, not to our new one
    
    The fix is trivial, although the algorithm not: we only allow overriding
    the network configuration when the disk information matches and we are
    not diskless, by adding the <"local_dev" in info'> test.
    
    Reviewed-by: ultrotter
    bf25af3b
bdev.py 73.3 KB