Open Stack

Hi, I'd like you to take a look at this patch for potential
DocImpact.
https://review.openstack.org/25887

Log:
commit c591276a170b59adec53cd7cd370515774d2f904
Author: gengjh <gengjh at cn.ibm.com>
Date:   Mon Apr 1 22:11:50 2013 +0800

    Enhance the validation of the quotas update
    
    Need check whether the already used and reserved exceeds the new quota
    before update it.
    
    DocImpact
    
    Fix bug 1160749
    
    Change-Id: Iba3cee0f0d92cf2e6d64bc83830b0091992d1ee9