270546 – nullfs prevents zfs from freeing space
bugs.freebsd.org
how to reproduce:
1) mount zfs filesystem in 2 separate places with nullfs, ex /mount1 and /mount2
2) create file in /mount1
3) ls /mount2
4) rm /mount1/file
5) space not freed by zfs.
only umount of /mount2 frees space
Has anyone encountered it? Is there any way to fix it?