Re: PROBLEM: multiple mount of devices possible 2.4.0-test1 -

[Ton Hospel]

In article <[e-mail]>,
	Alexander Viro <[e-mail]> writes:
> On Sat, 30 Dec 2000, Ton Hospel wrote:
> 
>> It should still need a special flag or something, since it's
>> impossible for userspace to check this atomically.
> 
> To check _what_? Having the same tree mounted in several places is
> allowed. End of story. Atomicity of any kind is a non-issue - if you
> have processes that do not cooperate and do random mounts you are
> getting exactly what you are asking for.
> 

I wasn't talking about mounting the same device on different mount points.
If you ask for that, it's good that you nowadays you can get that (though
even there it might be a good idea to let the filesystem say if it can
support that or not)

I was talking about avoiding that the same device gets multiple mounted 
at the SAME place, e.g. when doing mount -a, which is often used as a
quick way to get the new entries in /etc/fstab

That would also be no problem if there were a standard about e.g. always
flocking /etc/mtab. But as far as I know there isn't such a standard.