[HDFS-10324] Trash directory in an encryption zone should be pre-created with correct permissions

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.8.0
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: encryption

Environment

CDH5.7.0

• Hadoop Flags: Reviewed

Release Note

HDFS will create a ".Trash" subdirectory when creating a new encryption zone to support soft delete for files deleted within the encryption zone. A new "crypto -provisionTrash" command has been introduced to provision trash directories for encryption zones created with Apache Hadoop minor releases prior to 2.8.0.

• Assignee: Wei-Chiu Chuang
• Reporter: Wei-Chiu Chuang
• Created: 22/Apr/16 06:21
• Updated: 30/Sep/20 02:41
• Resolved: 06/May/16 01:10

Description

We encountered a bug in HDFS-8831:
After HDFS-8831, a deleted file in an encryption zone is moved to a .Trash subdirectory within the encryption zone.

However, if this .Trash subdirectory is not created beforehand, it will be created and owned by the first user who deleted a file, with permission drwx------. This creates a serious bug because any other non-privileged user will not be able to delete any files within the encryption zone, because they do not have the permission to move directories to the trash directory.

We should fix this bug, by pre-creating the .Trash directory with sticky bit.

Issue Links

• breaks: HDFS-8831 Trash Support for deletion in HDFS encryption zone
• is related to: HDFS-15607 Create trash dir when allowing snapshottable dir