When I tried to upgrade a package with the newest RPM in rawhide, (i. e. rpm-4.0.1-0.13) it reported I had not enough free Inodes. As I use reiserfs (!!) this cannot be true due to the fact that reiserfs has no limitations in the number of inodes. (The Problems seems to be that reiserfs returns -1 as the number of free inodes, maybe the bug is not in rpm but in reiserfs)
FWIW, you are running on unreleased rpm-4.0.1 code, inode checks may be the least of your problems. Smells like a reiserfs problem. Work around by adding --ignoresize when installing packages, that should disable space/inode checks in rpm.