Open Stack

We recently ran into an issue where nova couldn't write an image file due to 
lack of space and so just quit reading from glance.

This caused glance to be stuck with an open file descriptor, which meant that 
the image consumed space even after it was deleted.

I have a crude fix for nova at "https://review.openstack.org/#/c/188179/" which 
basically continues to read the image even though it can't write it.  That seems 
less than ideal for large images though.

Is there a better way to do this?  Is there a way for nova to indicate to glance 
that it's no longer interested in that image and glance can close the file?

If I've followed this correctly, on the glance side I think the code in question 
is ultimately glance_store._drivers.filesystem.ChunkedFile.__iter__().

Chris