Index: oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/file/FileStore.java
===================================================================
--- oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/file/FileStore.java	(revision 1758900)
+++ oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/file/FileStore.java	(working copy)
@@ -129,7 +129,7 @@
     private static final Pattern FILE_NAME_PATTERN =
             Pattern.compile("(data|bulk)((0|[1-9][0-9]*)[0-9]{4})([a-z])?.tar");
 
-    private static final String FILE_NAME_FORMAT = "data%05d%s.tar";
+    static final String FILE_NAME_FORMAT = "data%05d%s.tar";
 
     private static final String LOCK_FILE_NAME = "repo.lock";
 
@@ -165,10 +165,6 @@
 
     private volatile List<TarReader> readers;
 
-    private int writeNumber;
-
-    private volatile File writeFile;
-
     private volatile TarWriter tarWriter;
 
     private final RandomAccessFile lockFile;
@@ -318,14 +314,13 @@
         this.stats = new FileStoreStats(builder.getStatsProvider(), this, size());
 
         if (!readOnly) {
+            int writeNumber = 0;
             if (indices.length > 0) {
-                this.writeNumber = indices[indices.length - 1] + 1;
-            } else {
-                this.writeNumber = 0;
+                writeNumber = indices[indices.length - 1] + 1;
             }
-            this.writeFile = new File(directory, format(
-                    FILE_NAME_FORMAT, writeNumber, "a"));
-            this.tarWriter = new TarWriter(writeFile, stats);
+            this.tarWriter = new TarWriter(directory, stats, writeNumber);
+        } else {
+            this.tarWriter = null;
         }
 
         if (!readOnly) {
@@ -671,7 +666,7 @@
         fileStoreLock.readLock().lock();
         try {
             readersSnapshot = ImmutableList.copyOf(readers);
-            writeFileSnapshotSize = writeFile != null ? writeFile.length() : 0;
+            writeFileSnapshotSize = tarWriter != null ? tarWriter.fileLength() : 0;
         } finally {
             fileStoreLock.readLock().unlock();
         }
@@ -1468,20 +1463,15 @@
      * @throws IOException
      */
     private void newWriter() throws IOException {
-        if (tarWriter.isDirty()) {
-            tarWriter.close();
-
+        TarWriter newWriter = tarWriter.renew();
+        if (newWriter != tarWriter) {
+            File writeFile = tarWriter.getFile();
             List<TarReader> list =
                     newArrayListWithCapacity(1 + readers.size());
             list.add(TarReader.open(writeFile, memoryMapping));
             list.addAll(readers);
             readers = list;
-
-            writeNumber++;
-            writeFile = new File(
-                    directory,
-                    format(FILE_NAME_FORMAT, writeNumber, "a"));
-            tarWriter = new TarWriter(writeFile, stats);
+            tarWriter = newWriter;
         }
     }
 
Index: oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/file/TarWriter.java
===================================================================
--- oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/file/TarWriter.java	(revision 1758900)
+++ oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/file/TarWriter.java	(working copy)
@@ -27,6 +27,8 @@
 import static com.google.common.collect.Maps.newHashMap;
 import static com.google.common.collect.Maps.newLinkedHashMap;
 import static com.google.common.collect.Sets.newHashSet;
+import static java.lang.String.format;
+import static org.apache.jackrabbit.oak.segment.file.FileStore.FILE_NAME_FORMAT;
 
 import java.io.Closeable;
 import java.io.File;
@@ -110,6 +112,8 @@
         }
     }
 
+    private final int writeIndex;
+
     /**
      * The file being written. This instance is also used as an additional
      * synchronization point by {@link #flush()} and {@link #close()} to
@@ -157,13 +161,20 @@
      */
     private final Map<UUID, Set<UUID>> graph = newHashMap();
 
+    /**
+     * Used for maintenance operations (GC or recovery) via the TarReader and tests
+     */
     TarWriter(File file) {
-        this(file, FileStoreMonitor.DEFAULT);
+        this.file = file;
+        this.monitor = FileStoreMonitor.DEFAULT;
+        this.writeIndex = -1;
     }
 
-    TarWriter(File file, FileStoreMonitor monitor) {
-        this.file = file;
+    TarWriter(File directory, FileStoreMonitor monitor, int writeIndex) {
+        this.file = new File(directory, format(FILE_NAME_FORMAT, writeIndex,
+                "a"));
         this.monitor = monitor;
+        this.writeIndex = writeIndex;
     }
 
     /**
@@ -308,10 +319,6 @@
         }
     }
 
-    boolean isDirty() {
-        return access != null;
-    }
-
     /**
      * Closes this tar file.
      *
@@ -352,6 +359,17 @@
         monitor.written(currentPosition - initialPosition);
     }
 
+    TarWriter renew() throws IOException {
+        checkState(writeIndex >= 0);
+        // If nothing was written to this file, then we're already done.
+        if (access == null) {
+            return this;
+        }
+        close();
+        int newIndex = writeIndex + 1;
+        return new TarWriter(file.getParentFile(), monitor, newIndex);
+    }
+
     private void writeBinaryReferences() throws IOException {
         int binaryReferenceSize = 0;
 
@@ -625,6 +643,14 @@
         }
     }
 
+    synchronized long fileLength() {
+        return file.length();
+    }
+
+    synchronized File getFile() {
+        return file;
+    }
+
     //------------------------------------------------------------< Object >--
 
     @Override
Index: oak-segment-tar/src/test/java/org/apache/jackrabbit/oak/segment/file/FileStoreStatsTest.java
===================================================================
--- oak-segment-tar/src/test/java/org/apache/jackrabbit/oak/segment/file/FileStoreStatsTest.java	(revision 1758900)
+++ oak-segment-tar/src/test/java/org/apache/jackrabbit/oak/segment/file/FileStoreStatsTest.java	(working copy)
@@ -73,31 +73,30 @@
     @Test
     public void tarWriterIntegration() throws Exception{
         StatisticsProvider statsProvider = new DefaultStatisticsProvider(executor);
-        FileStore store = fileStoreBuilder(segmentFolder.newFolder())
+        File directory = segmentFolder.newFolder();
+        FileStore store = fileStoreBuilder(directory)
                 .withStatisticsProvider(statsProvider)
                 .build();
-        
         FileStoreStats stats = new FileStoreStats(statsProvider, store, 0);
-        
         try {
             long initialSize = stats.getApproximateSize();
-
             UUID id = UUID.randomUUID();
             long msb = id.getMostSignificantBits();
             long lsb = id.getLeastSignificantBits() & (-1 >>> 4); // OAK-1672
             byte[] data = "Hello, World!".getBytes(UTF_8);
 
-            File file = segmentFolder.newFile();
-            try (TarWriter writer = new TarWriter(file, stats)) {
+            TarWriter writer = null;
+            try {
+                writer = new TarWriter(directory, stats, 0);
                 writer.writeEntry(msb, lsb, data, 0, data.length, 0);
+            } finally {
+                writer.close();
             }
-
-            assertEquals(stats.getApproximateSize() - initialSize, file.length());
-            
+            assertEquals(stats.getApproximateSize() - initialSize,
+                    writer.fileLength());
         } finally {
             store.close();
         }
-        
         assertEquals(1, stats.getJournalWriteStatsAsCount());
     }