HAL and what drives me crazy: "umount: /mnt/cdrom: device is busy"

[David Zeuthen]

On Wed, Oct 01, 2003 at 03:18:56AM -0400, Norbert Frese wrote:
> 2) UNMOUNTING "BUSY" DEVICES
> 
> "umount: /mnt/cdrom: device is busy". This is one of the messages that
> really drives me crazy. Sometimes it's really hard for me to find out
> which app is "blocking" a certain mount-point. Sometimes i have to close
> all apps or even log out or restart the computer (If there is some
> crashed or orphan app running in the background).
> 
> I don't think the HAL-spec tackles the problem of unmounting devices
> which are 'blocked' by applications (like file-managers...).
> 
> My proposal would be a three stage umount procedure:
> 
> the user clicks eject or umount on the desktop-icon (or types something
> like "want2umount" in the terminal) ->
> 
> a) "umount aware" applications which register to the HAL receive a
> callback or signal that a certain mount-point wants to be released. They
> can react by prompting the user to save data, shut down or change to a
> different directory.
> 
> b) if there are still apps "blocking" the mount-point -> a pop-up list
> of those apps is displayed - with a term/kill button next to them.
> 
> c) umount is performed (if it still doesn't succeed the user is prompted
> for "lazy umount").
> 
> i dont know if this makes sense to a unix/linux expert - and maybe there
> are better ways to cope with this problem...
> 

I'm no expert when it comes to this, but I think implementing this
proposal would be more fixing the symptoms than the problem. It would
also be bad UI to ask whether the fs should be lazy unmounted.

Note that for some storage devices, for example USB or IEEE1394 optical 
drivers, they may be unplugged by the user so this proposal wouldn't
work there.

I'd rather want the 'umount -f' to work for any mounted file system. But
I don't know enough about the various kernels to say whether this is 
possible, desirable or how the applications with open files would react.

Just my euro 0.0172.

Thanks,
David


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