Re: SCSI/CAM status, etc.

Hi Dave,

>> 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.

As far as support functions go, I'm thinking about doing is this:
at the top, write a set of functions that convert from VSTa FS_
messages to VFS function calls, and convert the return values to
the appropriate message replys. This code would borrow from vstafs
and/or dosfs. At the bottom I would write a set of bio style functions.
isofs would sit in the middle.

The advantage of this approach is that it shouldn't require radical
changes to isofs itself. This would make tracking changes to the
code easier.

>> 2) does it seem reasonable to, by default, to allow the following
>> access to SCSI devices:
>> :
>> :
>
>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=..."

The "stat -w" is a good idea. However, I'd also like to set up some
reasonable defaults so, the sysadm wouldn't have to do this for the
normal case.

> 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.

Let me know if there's any common code we can share.

                                        Mike Larson
Received on Sun May 29 10:37:25 1994