ZFS_TASKQ_ACTIVE
ASSERT(ztq->ztq_flags & ZFS_TASKQ_ACTIVE);
while (ztq->ztq_flags & ZFS_TASKQ_ACTIVE) {
ztq->ztq_flags = flags | ZFS_TASKQ_ACTIVE;
ztq->ztq_flags &= ~ZFS_TASKQ_ACTIVE;