Re: nullfs: contents under mount point not visible via null mount

[Eric Haszlakiewicz <erh%nimenees.com@localhost>]

On September 8, 2014 5:58:10 PM EDT, Rhialto <rhialto%falu.nl@localhost> wrote:
>On Mon 08 Sep 2014 at 13:44:28 -0400, Toby Karyadi wrote:
>> Say, if I have the following:
>> - a path a/b/c/d
>> - a/b/c/d is a mount point for some filesystem
>> - an alternate path alt-hier/c, which is a null mount for a/b/c
>> 
>> Then, listing alt-hier/c/d won't show the content of the filesystem
>mounted
>> on a/b/c/d. This is surprising, since I thought that I'd see the
>content of
>> a/b/c/d. Is this a bug, or my misunderstanding of how the nullfs is
>supposed
>> to work? I also tried this on FreeBSD 7.1 and got the same behavior;
>hmmpfh.
>
>I believe that is a general effect. You'd see it with NFS too: if you
>export a/b/c to some client, it will not see whatever the server has
>mounted on a/b/c/d.
>

Except that with NFS you export a *filesystem*, while nullfs talks about 
mapping a portion of the *namespace* instead.
If the man page is an accurate representation of how it's supposed to work, 
then all mounted filesystems should show up.  If not, then the man page could 
use some clarification.

Eric