MSDOS could do this only at a huge loss in performance -- it simply
never cached anything on a floppy device. However, seriously though,
it wouldn't be that hard to write a daemon (Solaris calls it vold)
which monitors a removable-media drive and mounts it on demand.
The problem is when the floppy is ejected and the filesystem is busy.
If the hardware was designed properly -- and there is such hardware
avaiable -- there would be a button that would give a signal to the OS
to unmount the filesystem and eject the disk via a motor mechanism.
Unfortunately, the bulk of PC hardware isn't, which means you pretty
much need to handle the case where the user physically removed the
media while it was being used, which leads to some nasty problems even
if you never cache a single block.
There was something called "supermount" by Stephen Tweedie which did
all of this. I don't know what happened with it.
Now, CD-ROMs, IDE floppies, etc tend to be motorized and lockable. I
believe Microsoft has been pushing for an extension to the IDE
standard which will support media insert notification and
button-push-while-locked ("umount me now") notification. If that is
correct those would be easy to support.
-hpa
-- <hpa@transmeta.com> at work, <hpa@zytor.com> in private! "Unix gives you enough rope to shoot yourself in the foot."- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/