1. An application requests that a file named C:fooar.doc be opened.
2. The object manager finds the device object HarddiskVolume2, looks up the parse procedure IopParseDevice from the object’s type, and invokes it with the file’s name relative to the root of the file system.
3. IopParseDevice() allocates a file object and passes it to the file system, which fills in the details of how to access C:fooar.doc on the volume.
4. When the file system returns, IopParseDevice() allocates an entry for the file object in the handle table for the current process and returns the handle to the application.
If the file cannot successfully be opened, IopParseDevice() deletes the file object it allocated and returns an error indication to the application.