[HDFS-7744] Fix potential NPE in DFSInputStream after setDropBehind or setReadahead is called

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.6.0
• Fix Version/s: 2.7.0
• Component/s: hdfs-client
• Target Version/s: 2.7.0
• Assignee: Colin McCabe
• Reporter: Colin McCabe
• Created: 06/Feb/15 20:34
• Updated: 15/Sep/22 01:23
• Resolved: 10/Feb/15 04:17

Description

Fix a potential NPE in DFSInputStream after setDropBehind or setReadahead is called. These functions clear the blockReader, but don't set blockEnd to -1, which could lead to DFSInputStream#seek attempting to derference blockReader even though it is null.

Issue Links

• relates to: HBASE-17501 NullPointerException after Datanodes Decommissioned and Terminated
• relates to: HDFS-7694 FSDataInputStream should support "unbuffer"