Comment 7 for bug 1191730

Reviewed: https://review.openstack.org/33263
Committed: http://github.com/openstack/cinder/commit/33f6d78c3a0f3e3c34e8b91a8dffb1391f7b46b6
Submitter: Jenkins
Branch: master

commit 33f6d78c3a0f3e3c34e8b91a8dffb1391f7b46b6
Author: Sergey Vilgelm <email address hidden>
Date: Mon Jun 24 15:19:50 2013 +0400

    Do not raise NEW exceptions

    Raising NEW exception is bad practice, because we lose TraceBack.
    So all places like:

    except SomeException as e:
        raise e

    should be replaced by

    except SomeException:
        raise

    If we are doing some other actions before reraising we should
    store information about exception then do all actions and then
    reraise it. This is caused by eventlet bug. It lost information
    about exception if it switch threads.

    fixes bug 1191730
    Change-Id: Ic2be96e9f03d2ca46d060caf6f6f7f713a1d6b82