From 5d427ff6e535ba60f0d2f3e07781de9fcdc8fd42 Mon Sep 17 00:00:00 2001
From: Maciej Sokol <maciej.sokol@ericsson.com>
Date: Tue, 19 Apr 2022 10:22:55 +0200
Subject: [PATCH] Fsync TOC and Digest files after they're written

Patch by Maciej Sokol; reviewed by brandonwilliams and bereng for
CASSANDRA-10709
---
 CHANGES.txt                                       |  1 +
 .../org/apache/cassandra/io/sstable/SSTable.java  |  5 ++++-
 .../cassandra/io/util/DataIntegrityMetadata.java  | 15 +++++++++------
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index df06fa3a95..4462e22067 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,5 @@
 3.0.27
+ * fsync TOC and digest files (CASSANDRA-10709)
  * Fix URISyntaxException in nodetool with updated Java (CASSANDRA-17581)
  * Schema mutations may not be completed on drain (CASSANDRA-17524)
  * Fix data corruption in AbstractCompositeType due to static boolean byte buffers (CASSANDRA-14752)
diff --git a/src/java/org/apache/cassandra/io/sstable/SSTable.java b/src/java/org/apache/cassandra/io/sstable/SSTable.java
index b5703fcd72..6bfb0bf83a 100644
--- a/src/java/org/apache/cassandra/io/sstable/SSTable.java
+++ b/src/java/org/apache/cassandra/io/sstable/SSTable.java
@@ -299,10 +299,13 @@ public abstract class SSTable
     protected static void appendTOC(Descriptor descriptor, Collection<Component> components)
     {
         File tocFile = new File(descriptor.filenameFor(Component.TOC));
-        try (PrintWriter w = new PrintWriter(new FileWriter(tocFile, true)))
+        try (FileOutputStream fos = new FileOutputStream(tocFile);
+             PrintWriter w = new PrintWriter(fos))
         {
             for (Component component : components)
                 w.println(component.name);
+            w.flush();
+            fos.getFD().sync();
         }
         catch (IOException e)
         {
diff --git a/src/java/org/apache/cassandra/io/util/DataIntegrityMetadata.java b/src/java/org/apache/cassandra/io/util/DataIntegrityMetadata.java
index cbf5753edd..79dfe2f64a 100644
--- a/src/java/org/apache/cassandra/io/util/DataIntegrityMetadata.java
+++ b/src/java/org/apache/cassandra/io/util/DataIntegrityMetadata.java
@@ -17,20 +17,20 @@
  */
 package org.apache.cassandra.io.util;
 
-import java.io.BufferedWriter;
+import java.io.BufferedOutputStream;
 import java.io.Closeable;
 import java.io.DataOutput;
+import java.io.DataOutputStream;
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOError;
 import java.io.IOException;
 import java.nio.ByteBuffer;
-import java.nio.file.Files;
+import java.nio.charset.StandardCharsets;
 import java.util.zip.CRC32;
 import java.util.zip.CheckedInputStream;
 import java.util.zip.Checksum;
 
-import com.google.common.base.Charsets;
-
 import org.apache.cassandra.io.FSWriteError;
 import org.apache.cassandra.io.sstable.Component;
 import org.apache.cassandra.io.sstable.Descriptor;
@@ -209,9 +209,12 @@ public class DataIntegrityMetadata
             if (descriptor.digestComponent == null)
                 throw new NullPointerException("Null digest component for " + descriptor.ksname + '.' + descriptor.cfname + " file " + descriptor.baseFilename());
             File outFile = new File(descriptor.filenameFor(descriptor.digestComponent));
-            try (BufferedWriter out =Files.newBufferedWriter(outFile.toPath(), Charsets.UTF_8))
+            try (FileOutputStream fos = new FileOutputStream(outFile);
+                 DataOutputStream out = new DataOutputStream(new BufferedOutputStream(fos)))
             {
-                out.write(String.valueOf(fullChecksum.getValue()));
+                out.write(String.valueOf(fullChecksum.getValue()).getBytes(StandardCharsets.UTF_8));
+                out.flush();
+                fos.getFD().sync();
             }
             catch (IOException e)
             {