On Mon, 2004-05-31 at 21:30, Alan Cox wrote: > > Wouldn't it suffice with just an option to mount(1), e.g. have as few > > changes to how this impact user space as possible. I mean, at the end of > > the day, isn't this just about the kernel locking/unlocking the drive > > (same for e.g. USB storage) only when there is I/O? > > To do it properly you need a bit more because users may change CD-ROMs and you > probably want to do "Please insert 'Install Disk 2'" type dialogs. > > Internally the kernel really doesn't deal with disks going away when they are > wanted. Volumagic can cope with > > cd /mnt/cdrom > eject > insert new cd > ls > > and also with requests when the disk is removed - not all file systems handle > media vanishing as a routine thing. > In my, possibly uninformed, opinion it would be nicest if optical discs just appeared to the user like the other block devices out there e.g. /sys/block/hdc /sys/block/hdc/hdc1 Then your change notification would just be a hotplug event. Further, for a mixed CD-ROM disc you would also have /sys/block/hdc/hdc2 so you can access the data and audio parts simultaneously. This works on Mac OS X, though the drive makes a lot of noise. I'm not sure how to achieve this on Linux. David
