Propagates errors in Rfile.closeDeepCopies (apache#5248)

Rfile.closeLocalityGroupReaders() was suppressing IOExceptions.
This method was called by Rfile.closeDeepCopies() which was called by
FileManager.releaseReaders().  Suppressing the exception meant that
releaseReaders() did not see the exception and would decided to return
the rfile to the pool when it should not.

The only other code calling Rfile.closeLocalityGroupReaders() was
Rfile.close(). Refactored the code so that Rfile.close() still suppressed
the exception and Rfile.closeDeepCopies() does not suppress.  Tried to
preserve the behavior that Rfile.close() closes as many of its
underlying resource as possible even if some exceptions occur.

Author: keith-turner

core/src/main/java/org/apache/accumulo/core/file/rfile/RFile.java

@@ -1288,24 +1288,32 @@ public Reader(CachableBlockFile.CachableBuilder b) throws IOException {
       this(new CachableBlockFile.Reader(b));
     }
 
-    private void closeLocalityGroupReaders() {
+    private void closeLocalityGroupReaders(boolean ignoreIOExceptions) throws IOException {
       for (LocalityGroupReader lgr : currentReaders) {
         try {
           lgr.close();
         } catch (IOException e) {
-          log.warn("Errored out attempting to close LocalityGroupReader.", e);
+          if (ignoreIOExceptions) {
+            log.warn("Errored out attempting to close LocalityGroupReader.", e);
+          } else {
+            throw e;
+          }
         }
       }
     }
 
     @Override
-    public void closeDeepCopies() {
+    public void closeDeepCopies() throws IOException {
+      closeDeepCopies(false);
+    }
+
+    private void closeDeepCopies(boolean ignoreIOExceptions) throws IOException {
       if (deepCopy) {
         throw new RuntimeException("Calling closeDeepCopies on a deep copy is not supported");
       }
 
       for (Reader deepCopy : deepCopies) {
-        deepCopy.closeLocalityGroupReaders();
+        deepCopy.closeLocalityGroupReaders(ignoreIOExceptions);
       }
 
       deepCopies.clear();
@@ -1317,8 +1325,9 @@ public void close() throws IOException {
         throw new RuntimeException("Calling close on a deep copy is not supported");
       }
 
-      closeDeepCopies();
-      closeLocalityGroupReaders();
+      // Closes as much as possible igoring and logging exceptions along the way
+      closeDeepCopies(true);
+      closeLocalityGroupReaders(true);
 
       if (sampleReaders != null) {
         for (LocalityGroupReader lgr : sampleReaders) {