1. 22 Jun, 2009 1 commit
    • Joel Becker's avatar
      ocfs2: Provide the ocfs2_dlm_lvb_valid() stack API. · 1c520dfb
      Joel Becker authored
      The Lock Value Block (LVB) of a DLM lock can be lost when nodes die and
      the DLM cannot reconstruct its state.  Clients of the DLM need to know
      this.
      
      ocfs2's internal DLM, o2dlm, explicitly zeroes out the LVB when it loses
      track of the state.  This is not a standard behavior, but ocfs2 has
      always relied on it.  Thus, an o2dlm LVB is always "valid".
      
      ocfs2 now supports both o2dlm and fs/dlm via the stack glue.  When
      fs/dlm loses track of an LVBs state, it sets a flag
      (DLM_SBF_VALNOTVALID) on the Lock Status Block (LKSB).  The contents of
      the LVB may be garbage or merely stale.
      
      ocfs2 doesn't want to try to guess at the validity of the stale LVB.
      Instead, it should be checking the VALNOTVALID flag.  As this is the
      'standard' way of treating LVBs, we will promote this behavior.
      
      We add a stack glue API ocfs2_dlm_lvb_valid().  It returns non-zero when
      the LVB is valid.  o2dlm will always return valid, while fs/dlm will
      check VALNOTVALID.
      Signed-off-by: default avatarJoel Becker <joel.becker@oracle.com>
      Acked-by: default avatarMark Fasheh <mfasheh@suse.com>
      1c520dfb
  2. 17 Jun, 2009 39 commits