[mythtv] [mythtv-commits] Ticket #7949: Multiple identical partitions on identical drives are listed as only one Mythtv drive

[f-myth-users at media.mit.edu]

    > Date: Sat, 23 Jan 2010 17:35:42 -0000
    > From: "MythTV" <mythtv at cvs.mythtv.org>

    > Changes (by cpinkham):

    > Comment:

    >  This is a known issue that automatically corrects itself once you have the
    >  first recording on each drive.  We have not come up with a determinate,
    >  easy, replicatable solution to determine whether
    >  filesystems are indeed the same filesystem, links to the same filesystem,
    >  bind mounts, nfs mounts, cifs mounts, etc. blah to the same filesystem.

I've never been clear about why this is true.  Maybe this was
discussed in the past and I just missed it somehow.

Wouldn't it be possible to write a different nonce to every filesystem
and then see which nonces have appeared in multiple places?  After
all, Myth -does- have permission to write (if it didn't, we wouldn't
care if they were the same because we're not trying to load-balance
to them), so why not gensym a name for each, touch it, check which
have appeared where, and then delete the nonces again?  It seems like
this would be much simpler logic (and simpler to prove correct) than
the current heuristic.

What am I missing?