[HDFS-14028] HDFS OIV temporary dir deletes folder

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.4, 3.1.2, 3.3.0, 3.2.1
• Component/s: hdfs
• Hadoop Flags: Reviewed
• Assignee: Adam Antal
• Reporter: Adam Antal
• Created: 25/Oct/18 14:54
• Updated: 06/Nov/18 05:53
• Resolved: 27/Oct/18 00:31

Description

The Hadoop Offline Image Viewer tool has an undocumented 'feature' where it will silently delete the directory passed in with the -t flag. This blew away some important files when someone used a sensible, but ultimately poor choice for this directory as the deletion isn't documented.

For example, if someone were, as root do: 'hdfs oiv -i fsimage_00000000000307052343 -p Delimited -t / -o image', bad things would happen. This behavior should be documented and probably have a dialog or throwing exception.

There is a piece of code from PBImageTextWriter where a check can be added:

LevelDBMetadataMap(String baseDir) throws IOException {
  File dbDir = new File(baseDir);
  if (dbDir.exists()) {
    FileUtils.deleteDirectory(dbDir);
  }
  ...