[patch 5/5] use inode_change_ok for setattr permission checking

[Timothy Shimmin]

Christoph Hellwig wrote:
> Instead of implementing our own checks use inode_change_ok to check for
> necessary permission in setattr.  There is a slight change in behaviour
> as inode_change_ok doesn't allow i_mode updates to add the suid or sgid
> without superuser privilegues while the old XFS code just stripped away
> those bits from the file mode.
> 
> (First sent on Semptember 29th)
(No reply from Question on Nov 12th:)

I just wanted to run this thru an amended xfstests/193 first.

Thanks,
--Tim