r297203,r297256:

r297156:
  Track filemon usage via a proc.p_filemon pointer rather than its own lists.
r297157:
  Stop tracking stat(2).
r297158:
  Consolidate open(2) and openat(2) code.
r297159:
  Use curthread for vn_fullpath.
r297161:
  Attempt to use the namecache for openat(2) path resolution.
r297172:
  Consolidate common link(2) logic.
r297200:
  Follow-up r297156: Close the log in filemon_dtr rather than in the last
  reference.
r297201:
  Return any log write failure encountered when closing the filemon fd.
r297202:
  Remove unused done argument to copyinstr(9).
r297203:
  Handle copyin failures.
r297256:
  Remove unneeded return left from refactoring.