2001-11-20 19:42:47

by Andries E. Brouwer

[permalink] [raw]
Subject: Re: Linux can use a mountpoint for 2 Filesystems

hpa:

> There are real reasons to overmount a filesystem. It's getting to be
> a usability problem, probably because Linux (UNLIKE MOST OTHER UNIXES)
> didn't allow it until just recently. This change caused some
> problems, including with the automount daemon. I would like to see an
> option to mount(8) to allow it, by default disallow by policy.

mount(8) does not necessarily have such information:
/etc/mtab is just a random file with random contents,
and /proc/mounts need not exist.

The cleanest way to do what you suggest would be to make the kernel
refuse an overmount unless the mount(2) flags included the
"overmount" flag.

Andries


2001-11-20 19:45:26

by H. Peter Anvin

[permalink] [raw]
Subject: Re: Linux can use a mountpoint for 2 Filesystems

[email protected] wrote:

> hpa:
>
>
>>There are real reasons to overmount a filesystem. It's getting to be
>>a usability problem, probably because Linux (UNLIKE MOST OTHER UNIXES)
>>didn't allow it until just recently. This change caused some
>>problems, including with the automount daemon. I would like to see an
>>option to mount(8) to allow it, by default disallow by policy.
>>
>
> mount(8) does not necessarily have such information:
> /etc/mtab is just a random file with random contents,
> and /proc/mounts need not exist.
>
> The cleanest way to do what you suggest would be to make the kernel
> refuse an overmount unless the mount(2) flags included the
> "overmount" flag.
>


Agreed.

-hpa