Handle adding file reference where existing dir has invalid content

2 files changed, 55 insertions, 5 deletions

diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/filedistribution/FileDirectory.java b/configserver/src/main/java/com/yahoo/vespa/config/server/filedistribution/FileDirectory.java
index 432cbc4d997..861f920e41e 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/filedistribution/FileDirectory.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/filedistribution/FileDirectory.java
@@ -101,18 +101,42 @@ public class FileDirectory  {
     public FileReference addFile(File source) {
         try {
             Long hash = computeReference(source);
-            FileReference reference = new FileReference(Long.toHexString(hash));
-            return addFile(source, reference);
+            verifyExistingFile(hash);
+            FileReference fileReference = fileReferenceFromHash(hash);
+            return addFile(source, fileReference);
         } catch (IOException e) {
             throw new IllegalArgumentException(e);
         }
     }
 
+    // If there is exists a directory for a file reference, but it does not have correct hash, we delete everything in it
+    private void verifyExistingFile(Long hashOfFileToBeAdded) throws IOException {
+        FileReference fileReference = fileReferenceFromHash(hashOfFileToBeAdded);
+        File destinationDir = destinationDir(fileReference);
+        if (!destinationDir.exists()) return;
+
+        Long hashOfExistingFileReference = computeReference(destinationDir);
+        if (hashOfExistingFileReference.longValue() != hashOfFileToBeAdded.longValue()) {
+            log.log(LogLevel.ERROR, "Directory for file reference ' " + fileReference.value() +
+                    "' has content that does not match its hash, deleting everything in " +
+                    destinationDir.getAbsolutePath());
+            IOUtils.recursiveDeleteDir(destinationDir);
+        }
+    }
+
+    private File destinationDir(FileReference fileReference) {
+        return new File(root, fileReference.value());
+    }
+
+    private FileReference fileReferenceFromHash(Long hash) {
+        return new FileReference(Long.toHexString(hash));
+    }
+
     FileReference addFile(File source, FileReference reference) {
         ensureRootExist();
         try {
             logfileInfo(source);
-            File destinationDir = new File(root, reference.value());
+            File destinationDir = destinationDir(reference);
             Path tempDestinationDir = Files.createTempDirectory(root.toPath(), "writing");
             File destination = new File(tempDestinationDir.toFile(), source.getName());
             if (!destinationDir.exists()) {
@@ -121,8 +145,9 @@ public class FileDirectory  {
                 if (source.isDirectory()) {
                     log.log(LogLevel.DEBUG, "Copying source " + source.getAbsolutePath() + " to " + destination.getAbsolutePath());
                     IOUtils.copyDirectory(source, destination, -1);
-                } else
+                } else {
                     copyFile(source, destination);
+                }
                 if (!destinationDir.exists()) {
                     log.log(LogLevel.DEBUG, "Moving from " + tempDestinationDir + " to " + destinationDir.getAbsolutePath());
                     if ( ! tempDestinationDir.toFile().renameTo(destinationDir)) {
diff --git a/configserver/src/test/java/com/yahoo/vespa/config/server/filedistribution/FileDirectoryTest.java b/configserver/src/test/java/com/yahoo/vespa/config/server/filedistribution/FileDirectoryTest.java
index 9b1d018f892..d35c6654658 100644
--- a/configserver/src/test/java/com/yahoo/vespa/config/server/filedistribution/FileDirectoryTest.java
+++ b/configserver/src/test/java/com/yahoo/vespa/config/server/filedistribution/FileDirectoryTest.java
@@ -11,6 +11,8 @@ import org.junit.rules.TemporaryFolder;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -39,7 +41,6 @@ public class FileDirectoryTest {
         assertEquals("2b8e97f15c854e1d", bar.value());
     }
 
-
     @Test
     public void requireThatFileReferenceWithSubDirectoriesWorks() throws IOException {
         FileDirectory fileDirectory = new FileDirectory(temporaryFolder.getRoot());
@@ -64,6 +65,30 @@ public class FileDirectoryTest {
         assertEquals("9ca074b47a4b510c", fileReference.value());
     }
 
+    @Test
+    public void requireThatExistingDirWithInvalidContentIsDeleted() throws IOException {
+        FileDirectory fileDirectory = new FileDirectory(temporaryFolder.getRoot());
+
+        String subdirName = "subdir";
+        File subDirectory = new File(temporaryFolder.getRoot(), subdirName);
+        createFileInSubDir(subDirectory, "foo");
+        FileReference fileReference = fileDirectory.addFile(subDirectory);
+        File dir = fileDirectory.getFile(fileReference);
+        assertTrue(dir.exists());
+        assertTrue(new File(dir, "foo").exists());
+        assertFalse(new File(dir, "doesnotexist").exists());
+        assertEquals("1315a322fc323608", fileReference.value());
+
+        // Remove a file, directory should be deleted before adding a new file
+        Files.delete(Paths.get(fileDirectory.getPath(fileReference)).resolve("subdir").resolve("foo"));
+        fileReference = fileDirectory.addFile(subDirectory);
+        dir = fileDirectory.getFile(fileReference);
+        assertTrue(dir.exists());
+        assertTrue(new File(dir, "foo").exists());
+        assertFalse(new File(dir, "doesnotexist").exists());
+        assertEquals("1315a322fc323608", fileReference.value());
+    }
+
     // Content in created file is equal to the filename string
     private FileReference createFile(String filename) throws IOException {
         File file = temporaryFolder.newFile(filename);