In Diagnose | Information | CIFS/SMB there should be al list for all shares and open files. in 0.68xx this information works well. now in 0.69.1 I always get no info at all (empty list). This is broken in 0.69-4276 i386/32bit but it's never bothered me because it's rare I forget what I'm sharing. It does work again it 7.
Running FreeNAS Full 0.69-4276 on Asus P4P800-VM, 2.4 Ghz i386, 512Mb RAM, Promise SATA300-TX4, 1.5Tb+ storage.
Others report 0.69.1 stable, amd64, embedded works as expected.
Danmero suggested filing a bug report.