Hi Christian,

One more question...

quoted

      The propagation field is used to specify the propagation typ
      of the mount or mount tree.  Mount propagation options are
      mutually exclusive; that is, the propagation values behave
      like an enum.  The supported mount propagation types are:

The manual page text doesn't actually say it, but if the 'propagation'
field is 0, then this means leave the propagation type unchanged, 
right? This of course should be mentioned in the manual page.

Cheers,

Michael

-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/