I was wondering why my Fedora 44 is slow running inside a virtual machine; finally I found that it is wasting CPU scanning huge imported filesystem from the host, via virtiofs. The fix is very simple, add virtiofs to PRUNEFS list inside /etc/updatedb.conf. Since this list already has 9p and various networked / distributed filesystems, the fact that it does not currently have virtiofs is an obvious omission.

Reproducible: Always

Steps to Reproduce:
1. construct a virtual machine with virtiofs attached, pointing to a very large filesystem
2. install Fedora 44 inside the virtual machine
3. watch updatedb trying to index the imported virtiofs filesystem
Actual Results:
large CPU utilization by /usr/bin/updatedb

Expected Results:
small or no CPU utilization by /usr/bin/updatedb

Additional Information:
Unexpectedly for the user, updatedb is trying to index a virtiofs filesystem. The updatedb.conf can be used to prevent this and indeed it is used for a range of filesystems including 9p (similar filesystem to virtiofs). The fix is for the user to add virtiofs to PRUNEFS in /etc/updatedb.conf, or ideally for the package to do it in the package provided configuration. This configuration is owned by the package itself - plocate project does not have a source file for default configuration.