[HDFS-2034] length in getBlockRange becomes -ve when reading only from currently being written blk

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.23.0
• Component/s: hdfs-client
• Hadoop Flags: Reviewed
• Assignee: John George
• Reporter: John George
• Created: 04/Jun/11 04:44
• Updated: 15/Nov/11 00:52
• Resolved: 08/Jul/11 20:19

Description

This came up during HDFS-1907. Posting an example that Todd posted in HDFS-1907 that brought out this issue.

Here's an example sequence to describe what I mean:
1. open file, write one and a half blocks
2. call hflush
3. another reader asks for the first byte of the second block

In this case since offset is greater than the completed block length, the math in getBlockRange() of DFSInputStreamer.java will set "length" to negative.