Description of Problem:

Disk space check in spec's "spaceof" scriptlet reports incorrect amount of
free disk space if /var/tmp or /usr/src/redhat/BUILD is a loopback
filesystem. It reports free space of host partition which contained
filesystem file image instead.

Version-Release number of selected component (if applicable):

kernel-2.4.7-2

How Reproducible:

Always

Steps to Reproduce:
1. create ext2 filesystem in one big enough file, so that there would
remain less than 200MB of free space in it's host filesystem
2. loopback mount it either at /var/tmp or /usr/src/redhat/BUILD
3. rpmbuild --rebuild kernel-2.4.7-2.src.rpm

Actual Results:

Report that there are not enough free disk space, while actually there are
plenty of it

Expected Results:

Build should either report error if this configuration is not supported or
check for free space inside the loopback filesystem, not in it's host
filesystem

Additional Information:
	
It is very useful to temporary get more free disk space for rpm builds,
than to actually reserve this space during installation. I have FAT32
filesystem with big amount of free space and would like to use it sometimes
for Linux