Re: SCSI/CAM status, etc.

Hi Mike,

> Now for the questions:
>
> 1) I've found sources to two CDROM filesystems called isofs. One is
> from the BSD world and the other is from Linux. Both have heavy
> dependencies on *nix style kernel calls and header files. I think,
> however, with some conditional compilation and support functions, that
> the porting job shouldn't be too bad. Comments?

This sounds reasonable. I guess that the simplest way to go would be to
take either the vstafs or dosfs code (probably not bfs as it's not
hierarchical), strip out the fs dependencies and bolt new code around it.

I've never looked too closely at the ISO9660 fs, but are there writeable
versions or is it purely a read only fs - if it is I guess it should make
life a lot simpler :-)

> 2) does it seem reasonable to, by default, to allow the following
> access to SCSI devices:
>
> a) sys.sys only:
>
> a.1) SCSI DIRECT devices (eg, hard disks)
>
> a.1) SCSI bus management functions (eg, BUS RESET)
>
> b) sys.something-else (perhaps sys.io or just sys)
>
> b.1) SCSI CDROM devices
>
> b.2) SCSI SEQUENTIAL devices (eg, tapes)

Why not just make all of the devices sys.sys, but make the permissions
changable by the initial owner. This makes it easy for an initialisation
script to do something like:

        stat -w -p cam:scdrom0 "owner=..."

or:

        stat -w /dev/scdrom "acc=..."

(I'm not sure what the device names would actually be).

This way we can specify whatever permissions are wanted by individual
sysadms.

FWIW I've been thinking about doing something similar, and allowing this
sort of permission handling on a lot of the device servers I've been working
with recently.

                Regards,
                Dave
Received on Sat May 28 13:59:19 1994