revert the last commit because it caused this issue with zfs-fuse:
revert the last commit because it caused this issue with zfs-fuse:

bash-4.2# /home/zhihui/stable/zfs-fuse/src/zfs-fuse/zfs-fuse
bash-4.2# /home/zhihui/stable/zfs-fuse/src/cmd/zpool/zpool destroy zhihui_slash2_orange
zfsfuse_ioctl_read_loop(): file descriptor closed

pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable