Subject: Re: Questions about features of NetBSD
To: Aleksi Suhonen <>
From: Tobias Weingartner <weingart@austin.BrandonU.CA>
List: current-users
Date: 04/19/1995 20:40:17
> I am by no means an expert on any of this, but I still think the method
> you suggested is somewhat cumbersome and I generally don't like that
> information regarding the structure of a filesystem is to be kept in
> a file *within* that filesystem ... I feel it should be part of  the
> filesystem structure. Then again your version is as you mentioned a lot
> easier to implement ... (BUT ... while you're at it, why not just have
> ACL-files in all the directories that happen to have special settings?
> that way you could also add directory default settings in there with
> ease.) I guess buffing up the inode-structure would be the logical way?
> How about storing all this information inside directory-structures?

I'd *hate* to try and write the code for that.  ACLs tend to be variable
length records, or at the very least a varying amount of them.  Some files
have them, others don't, etc...

The nice thing about using a reserved inode, is that I can make a directory
entry point at that inode, and then use normal read/write/lock calls to
implement all the user level code.  There is a minimal of code change.  Also,
in case a kernel does not understand the ACLs, there is no problem.  It would
simply ignore the ACL files, albeit with a reduction in the security of
the system (potentially).

If someone (please!) who knows the kernel slightly better than me, could help
me with one thing, I think I'll try to code something up this weekend, and
see what happens with it.  I need to know how I can read data from a file
given an inode number, from within ufs_access().  Can anyone help me out here?

| Tobias Weingartner | Email: weingart@BrandonU.Ca | Need a Unix sys-admin?  |
| Box 27, Beulah, MB |-----------------------------| Send E-Mail for resume, |
| R0M 0B0, Canada    | Unix Guru? Admin, Sys-Prgmr | and other details...    |
|      %SYSTEM-F-ANARCHISM, The operating system has been overthrown         |