[HADOOP-12056] Use DirectoryStream in DiskChecker#checkDirs to detect errors when listing a directory

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.0
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: util
• Assignee: Zhihai Xu
• Reporter: Zhihai Xu
• Created: 02/Jun/15 21:19
• Updated: 30/Aug/16 01:26
• Resolved: 05/Jun/15 20:53

Description

DiskChecker#checkDirs should check null pointer for the return value from File#listFiles. Based on the document for File#listFiles at https://docs.oracle.com/javase/7/docs/api/java/io/File.html#listFiles() :

Returns null if an I/O error occurs.

So it will be good to check null pointer and throw DiskErrorException if it is null.