Re: [PATCH] drivers/block/scsi_ioctl.c, Video DVD playback support

[Jens Axboe <axboe@suse.de>]

On Tue, Jan 25 2005, Elias da Silva wrote:
> : Someone did actually have a demo of a small fs that allowed you to
> : fiddle with the status but possibly the code could get smarter for
> : "exclusive user of media". I'm not sure if that is worth it.
> 
> Do you have the name of the fs and/or the name of author?

If I'm not mistaken, Peter Jones has posted a few iterations of such an
fs some months ago.

> Do we have a clear understanding that this fs would only
> be a benefit if *All* the different ways to access the device would
> use the same policy enforcement and consistently allow or
> disallow certain operations regardless of the access method?

The command restriction table _only_ works through the SG_IO path, which
does include CDROM_SEND_PACKET as well since it is layered on top of
SG_IO. It doesn't control various driver ioctl exported interfaces, they
would need to add a callback to verify_command() for permission checks.

-- 
Jens Axboe