[LUCENE-5160] NIOFSDirectory, SimpleFSDirectory (others?) don't properly handle valid file and FileChannel read conditions

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.4, 6.0
• Fix Version/s: 4.5, 6.0
• Assignee: Grant Ingersoll
• Reporter: Grant Ingersoll
• Created: 08/Aug/13 19:18
• Updated: 28/Aug/22 13:51
• Resolved: 08/Aug/13 20:16

Description

Around line 190 of NIOFSDirectory, the loop to read in bytes doesn't properly handle the -1 condition that can be returned from FileChannel.read(). If it returns -1, then it will move the file pointer back and you will enter an infinite loop. SimpleFSDirectory displays the same characteristics, although I have only seen the issue on NIOFSDirectory.

The code in question from NIOFSDirectory:

try {
        while (readLength > 0) {
          final int limit;
          if (readLength > chunkSize) {
            // LUCENE-1566 - work around JVM Bug by breaking
            // very large reads into chunks
            limit = readOffset + chunkSize;
          } else {
            limit = readOffset + readLength;
          }
          bb.limit(limit);
          int i = channel.read(bb, pos);
          pos += i;
          readOffset += i;
          readLength -= i;
        }

Issue Links

• relates to: LUCENE-5164 Remove the OOM catching in SimpleFSDirectory and NIOFSDirectory
• relates to: LUCENE-5161 review FSDirectory chunking defaults and test the chunking