why can't i see *all* mounts with "mount"?

[John Wendel]

Mikkel L. Ellertson wrote:
> Robert P. J. Day wrote:
>>   i'm curious as to why the "mount" command won't show me all the
>> mounts that i can view via /proc/mounts.  for example, "mount" doesn't
>> show me the usbfs mount, or the selinuxfs mount, or ... well, you get
>> the idea.
>>
>>   were these mount types left out of the output of mount for a reason?
>> just curious.
>>
>> rday
>>
> Mount uses /etc/mtab - it is possible to mount file systems without 
> writing to mtab. Also, the file systems mounted before the root file 
> system is remounted r/w will not get written. On the other hand, 
> /proc/mounts shows all the mounts the kernel knows about.
> 
> I suspect the reason that mount does not use /proc/mounts is for a 
> couple of reasons. First of all, when it was written, there was not a 
> /proc file system. I believe you can also run a Linux system without a 
> /proc file system.
> 
> Mikkel
> 


Isn't it possible to make /etc/mtab a link to /proc/mounts?  I seem to 
remember that some distos do this.

Regards,

John