When GFS uses direct-io PR and CW locks are mixed together
    on a single resource.  To optimize the interaction between
    these two lock modes, GFS uses LM_FLAG_ANY to request that
    either of the modes be granted.  When the dlm carries out
    this optimization and grants a PR lock instead of a CW, or
    a CW instead of a PR, the mode is not switched on the non-
    master node.  So, for example, the lock will be requested
    in PR mode with the ALTCW flag, it will be granted on the
    master node in CW mode, but the non master (requesting)
    node will record the granted mode as PR.
    
    Fix by changing the grmode on the non-master node when we
    get ALTMODE back from the master.