BUG 800061 - HIGHMEM support is broken

[pv@xxxxxxxxxxxxx (ananth@xxxxxxxxxxxx)]

View Incident: 
http://co-op.engr.sgi.com/BugWorks/code/bwxquery.cgi?search=Search&wlong=1&view_type=Bug&wi=800061

Submitter : ananth                    Submitter Domain : engr               
Assigned Engineer : nb                Assigned Domain : sgi.com             
Assigned Group : xfs-linux            Category : software                   
Customer Reported : F                 Priority : 2                          
Project : xfs-linux                   Status : open                         
Description :
There are two problems in handling highmem with XFS:

1. consistent use of kmap/kunmap to get at the address
   of a page.

2. supporting highmem with kiobufs.

I'll check-in a short fix that will check, issue warning, etc.
if highmem is turned on.

ananth.