[LUCENE-8494] CFS leaks a file on exception opening it

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Cannot Reproduce
• Component/s: core/codecs
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Robert Muir
• Created: 09/Sep/18 15:45
• Updated: 28/Aug/22 15:35
• Resolved: 18/Dec/19 13:57

Description

If CFS hits an exception opening its file, it will leak the file handle. Found by Jenkins: https://jenkins.thetaphi.de/job/Lucene-Solr-7.x-Solaris/808/

 java.lang.RuntimeException: MockDirectoryWrapper: cannot close: there are still 7 open files: {_j.cfs=1, _h.cfs=1, _e.cfs=1, _g.cfs=1, _i.cfs=1, _k.cfs=1, _f.cfs=1}
...
Caused by: java.lang.RuntimeException: unclosed IndexInput: _f.cfs
        at org.apache.lucene.store.MockDirectoryWrapper.addFileHandle(MockDirectoryWrapper.java:730)
        at org.apache.lucene.store.MockDirectoryWrapper.openInput(MockDirectoryWrapper.java:773)
        at org.apache.lucene.codecs.lucene50.Lucene50CompoundReader.<init>(Lucene50CompoundReader.java:78)

Looks like it needs to move opening of handle into the try block (untested):

diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50CompoundReader.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50CompoundReader.java
index 7526c88c20..db54ecdee2 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50CompoundReader.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50CompoundReader.java
@@ -75,8 +75,8 @@ final class Lucene50CompoundReader extends Directory {
     }
     expectedLength += CodecUtil.footerLength(); 
 
-    handle = directory.openInput(dataFileName, context);
     try {
+      handle = directory.openInput(dataFileName, context);
       CodecUtil.checkIndexHeader(handle, Lucene50CompoundFormat.DATA_CODEC, version, version, si.getId(), "");
       
       // NOTE: data file is too costly to verify checksum against all the bytes on open,