illumos gate

Illumos issue 278 removed the use of pyzfs from zfs_main.c. The C
implementation of zfs_do_allow that replaced it calls zfs_open() with
ZFS_TYPE_FILESYSTEM, neglecting the volume type. This causes all allow
and unallow operations to fail for volumes. pyzfs used directly from
the command line still works though.

zfstest% zfs list rtall -o name,type rpool/test
NAME TYPE
rpool/test filesystem
rpool/test/vol volume
zfstest% sudo zfs allow jkennedy snapshot rpool/test/vol
cannot open 'rpool/test/vol': operation not applicable to datasets of this type
Failed to open Dataset rpool/test/vol
zfstest% sudo /usr/lib/zfs/pyzfs.py allow jkennedy snapshot rpool/test/vol
zfstest% sudo /usr/lib/zfs/pyzfs.py allow rpool/test/vol
--- Permissions on rpool/test/vol -----------------------------------
Local+Descendent permissions:
user jkennedy snapshot
zfstest% sudo zfs snapshot rpool/test/vol@test
zfstest% zfs list -rtall -o name,type rpool/test
NAME TYPE
rpool/test filesystem
rpool/test/vol volume
rpool/test/vol@test snapshot

The use of the asterisks in the error message is also quite unlike
anything I've seen from zfs errors in the past.