Comment 2 for bug 27417

(In reply to comment #1)
> Ben, please feel free to close this as wontfix if it's totally unreasonable to
> add such functionality to the mount call.

Yeah, I just don't think this is feasible. For vfat, this is done transparently,
because the filesystem itself doesn't support uid/gid. So it already has a
mechanism to emulate them (they don't really exist). Because it can do that, it
can emulate them at arbitrary values. It does not support changing the file
modes and permissions. So it has to have this emulation (e.g., you cannot change
the owner/group of a file on vfat, it's _always_ set at whatever it was mounted
with).

For things like ext2/ext3/xfs/etc, the file perms are specifically there for a
reason. Plus, these filesystems support other modes (suid, sgid) that could
prove dangerous in this use case.

I wont ever support it, but if upstream ever does, we'll get it sooner or later.