I have an application running called AppFS. This application has an ext2 filesystem just attached to the end of the file (it's positioned so that the application binary exists in a 1MB spacing area, followed by the ext2 data).

Now I've got FUSE embedded in the program and I've managed to extract the filesystem out of the application data into a temporary file so that FUSE can mount / use it.

The problem I have now is writing the temporary file back into the application file. I get "Text file busy" presumably because the application has locked itself and won't let writes occur.

Is there a way I can force the file to become unlocked so I can write data to it? (It's important to note that I'm not changing the application binary area - just rewriting the ext2 component.) It needs to be unlocked without requiring root permissions (unlocked by the same user who started the application).