ADE: Encryption failed for name:sdd1 type:part fstype:xfs mountpoint:/datadisk

I tried deploying two marketplace Ubuntu VMs (Canonical:UbuntuServer:16.04-LTS:latest) with a data disk.

And tried to encrypt the data disk with the following command and got the same error for both VMs:
```
$ az vm encryption enable --resource-group vm01 --name vm01 --disk-encryption-keyvault vault8167 --key-encryption-key key --volume-type data --output table
VM has reported a failure when processing extension 'AzureDiskEncryptionForLinux'. Error message: "Failed to encrypt data volumes with error: Encryption failed for name:sdd1 type:part fstype:xfs mountpoint:/datadisk label: model: size:268434407424 majmin:8:49 device_id:f8b3781b-1e82-4818-a1c3-63d806ec15bb, stack trace: Traceback (most recent call last):
File "/var/lib/waagent/Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.1.0.17/main/handle.py", line 1534, in daemon_encrypt
os_items_to_stamp=os_items_to_stamp):
File "/var/lib/waagent/Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.1.0.17/main/handle.py", line 1755, in daemon_encrypt_data_volumes
raise Exception(message)
Exception: Encryption failed for name:sdd1 type:part fstype:xfs mountpoint:/datadisk label: model: size:268434407424 majmin:8:49 device_id:f8b3781b-1e82-4818-a1c3-63d806ec15bb
```
AzureDiskEncryptionForLinux version is 1.1.0.17

**extension.log**:
```
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: [StatusReport (0)] msg: Encrypting 1 data volumes
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: 19688: [Info] Data volume /datadisk is mounted from /dev/sdd1
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: [StatusReport (0)] substatus: {"os": "NotEncrypted", "data": "EncryptionInProgress"}
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: 19688: [Info] Executing: /bin/umount /datadisk
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: 19688: [Info] encrypting: name:sdd1 type:part fstype:xfs mountpoint:/datadisk label: model: size:268434407424 majmin:8:49 device_id:f8b3781b-1e82-4818-a1c3-63d806ec15bb
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: 19688: [Warning] For VMSS we only do inplace headers
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: 19688: [Info] encrypt_inplace_without_seperate_header_file
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: 19688: [Info] encrypting device item: /dev/sdd1
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: 19688: [Info] the current phase is BackupHeader
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: 19688: [Warning] we only support ext file systems for centos 6.5/6.6/6.7 and redhat 6.7
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: 19688: [Info] archive the config file: /var/lib/azure_disk_encryption_config/azure_crypt_ongoing_item.ini
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: 19688: [Error] Failed to encrypt data volumes with error: Encryption failed for name:sdd1 type:part fstype:xfs mountpoint:/datadisk label: model: size:268434407424 majmin:8:49 device_id:f8b3781b-1e82-4818-a1c3-63d806ec15bb, stack trace: Traceback (most recent call last):
2018/10/04 05:53:53 File "/var/lib/waagent/Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.1.0.17/main/handle.py", line 1534, in daemon_encrypt
2018/10/04 05:53:53 os_items_to_stamp=os_items_to_stamp):
2018/10/04 05:53:53 File "/var/lib/waagent/Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.1.0.17/main/handle.py", line 1755, in daemon_encrypt_data_volumes
2018/10/04 05:53:53 raise Exception(message)
2018/10/04 05:53:53 Exception: Encryption failed for name:sdd1 type:part fstype:xfs mountpoint:/datadisk label: model: size:268434407424 majmin:8:49 device_id:f8b3781b-1e82-4818-a1c3-63d806ec15bb
2018/10/04 05:53:53
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: [StatusReport (0)] op: EnableEncryptionDataVolumes
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: [StatusReport (0)] status: error
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: [StatusReport (0)] code: 19
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: [StatusReport (0)] msg: Failed to encrypt data volumes with error: Encryption failed for name:sdd1 type:part fstype:xfs mountpoint:/datadisk label: model: size:268434407424 majmin:8:49 device_id:f8b3781b-1e82-4818-a1c3-63d806ec15bb, stack trace: Traceback (most recent call last):
2018/10/04 05:53:53 File "/var/lib/waagent/Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.1.0.17/main/handle.py", line 1534, in daemon_encrypt
2018/10/04 05:53:53 os_items_to_stamp=os_items_to_stamp):
2018/10/04 05:53:53 File "/var/lib/waagent/Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.1.0.17/main/handle.py", line 1755, in daemon_encrypt_data_volumes
2018/10/04 05:53:53 raise Exception(message)
2018/10/04 05:53:53 Exception: Encryption failed for name:sdd1 type:part fstype:xfs mountpoint:/datadisk label: model: size:268434407424 majmin:8:49 device_id:f8b3781b-1e82-4818-a1c3-63d806ec15bb
2018/10/04 05:53:53
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: [StatusReport (0)] substatus: {"os": "NotEncrypted", "data": "NotMounted"}
2018/10/04 05:53:53 [Microsoft.Azure.Security.AzureDiskEncryptionForLinux-1.0]: 19688: [Info] exiting daemon
```

After the encryption failed, I mounted back the data disk:
```
# cat /etc/fstab
UUID=fc9a41df-6d71-4f4f-a487-e5999bd67182 / ext4 defaults,discard 0 0
/dev/disk/cloud/azure_resource-part1 /mnt auto defaults,nofail,x-systemd.requires=cloud-init.service,comment=cloudconfig 0 2
UUID=d1be93dc-d5bb-4ecf-b5ed-f58fc45574cb /datadisk xfs defaults 1 0
# mount -a
# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdd 8:48 0 250G 0 disk
└─sdd1 8:49 0 250G 0 part /datadisk
sdb 8:16 0 7G 0 disk
└─sdb1 8:17 0 7G 0 part /mnt
sr0 11:0 1 1024M 0 rom
sdc 8:32 0 48M 0 disk
└─sdc1 8:33 0 47M 0 part /mnt/azure_bek_disk
sda 8:0 0 30G 0 disk
└─sda1 8:1 0 30G 0 part /
```