[HADOOP-13840] Implement getUsed() for ViewFileSystem

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0-alpha1
• Fix Version/s: 3.0.0-alpha2
• Component/s: viewfs
• Target Version/s: 3.0.0-alpha2
• Assignee: Manoj Govindassamy
• Reporter: Manoj Govindassamy
• Created: 29/Nov/16 02:08
• Updated: 01/Dec/16 02:46
• Resolved: 01/Dec/16 01:55

Description

ViewFileSystem doesn't override FileSystem#getUSed(). So, when file system used space is queried for slash root "/" paths, the default implementations tries to run the getContentSummary which crashes on seeing unexpected mount points under slash.

ViewFileSystem#getUsed() is not expected to collate all the space used from all the mount points configured under "/". Proposal is to avoid invoking FileSystem#getUsed() and throw NotInMountPointException until LinkMergeSlash is supported.