become_root() Necessary for Group Quota in quotas.c?

[Orion]

We have a situation in which the root user does not have access to the 
files contained in a directory with SGID set. When a user navigates to 
this directory and Samba attempts to request the quota for the 
directory, it fails when the code later attempts to do a stat on the 
file because of lack of permissions.

In the file samba/source3/smbd/quotas.c if the SGID bit is set, the code 
changes the effective GID to the GID of the folder, uses become_root() 
to change to root, and then requests the quota. However, if the SGID bit 
is not set, quotas.c requests the quota without using the become_root() 
function. The question I have is, why when the SGID bit is set does it 
change to root before requesting the quota?

Can we remove the become_root() function call for this instance and 
request the quota as the GID of the folder?

I tested removing the become_root() and unbecome_root() function calls, 
and for our particular setup, it works perfectly. However, I am curious 
if there is some other setup that may have issues if this bit is removed.