mount: could not find any free loop device

[Andras Simon]

I'm trying to

mount -o loop,offset=32256 /usr/local/kvm-images/WinXP.raw /mnt/

as I've done successfully several times before, but now I get

mount: could not find any free loop device

What can possibly use loop devices? There are eight processes called
loop0 through loop7, all started by kthread. But I've no idea what
they do and if it's them who are using the loop devices.

This is on Fedora 7.

Andras