[GSoC project] Implementation of ISO9660 filesystem

[Chris Johns]

On 5/04/11 4:42 PM, Sebastian Huber wrote:
> On 04/05/2011 12:36 AM, Chris Johns wrote:
>> On 4/04/11 9:22 PM, Sebastian Huber wrote:
>>>
>>> one of the big problems with removable media and RTEMS is that
>>> currently it is
>>> impossible to unmount a file system in use.  This is a fundamental
>>> flaw in the
>>> RTEMS file system layer.  We should address this somehow in this
>>> project (we
>>> need some sort of reference counting).
>>
>> I see the need to be able to forcible remove a mount and any open files
>> return an error when accessed how-ever the unmount call should be aloud
>> to fail if the media is valid and in use and call is not forced.
>
> Yes.  The problem is that there is currently no way to figure out if a file
> system is in use or not.  With in use I mean that there exist some nodes that
> belong to the file system.  The nodes may be not related to a file  descriptor.
>   We have also root and current directory nodes (chroot() and chdir()).
>

In the current code it attempts to unmount and if it fails it knows the 
file system is in use.

What is the use case for knowing the file system is in use and not 
attempting to unmount and seeing if it fails ?

Chris