HADOOP-11852. Disable symlinks in trunk.

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -201,6 +201,8 @@ Trunk (Unreleased)
     HADOOP-11850. Typos in hadoop-common java docs. (Surendra Singh Lilhore
     via jghoman)
 
+    HADOOP-11852. Disable symlinks in trunk.
+
   BUG FIXES
 
     HADOOP-11473. test-patch says "-1 overall" even when all checks are +1

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FSLinkResolver.java

@@ -95,6 +95,10 @@ public T resolve(final FileContext fc, final Path path) throws IOException {
               + " and symlink resolution is disabled ("
               + CommonConfigurationKeys.FS_CLIENT_RESOLVE_REMOTE_SYMLINKS_KEY + ").", e);
         }
+        if (!FileSystem.areSymlinksEnabled()) {
+          throw new IOException("Symlink resolution is disabled in"
+              + " this version of Hadoop.");
+        }
         if (count++ > FsConstants.MAX_PATH_LINKS) {
           throw new IOException("Possible cyclic loop while " +
                                 "following symbolic link " + path);

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileContext.java

@@ -1431,11 +1431,15 @@ public FsStatus next(final AbstractFileSystem fs, final Path p)
    *           <code>target</code> or <code>link</code> is not supported
    * @throws IOException If an I/O error occurred
    */
+  @SuppressWarnings("deprecation")
   public void createSymlink(final Path target, final Path link,
       final boolean createParent) throws AccessControlException,
       FileAlreadyExistsException, FileNotFoundException,
       ParentNotDirectoryException, UnsupportedFileSystemException, 
       IOException { 
+    if (!FileSystem.areSymlinksEnabled()) {
+      throw new UnsupportedOperationException("Symlinks not supported");
+    }
     final Path nonRelLink = fixRelativePart(link);
     new FSLinkResolver<Void>() {
       @Override

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileSystem.java

@@ -3296,4 +3296,19 @@ void printStatistics() throws IOException {
                          ": " + pair.getValue());
     }
   }
+
+  // Symlinks are temporarily disabled - see HADOOP-10020 and HADOOP-10052
+  private static boolean symlinksEnabled = false;
+
+  private static Configuration conf = null;
+
+  @VisibleForTesting
+  public static boolean areSymlinksEnabled() {
+    return symlinksEnabled;
+  }
+
+  @VisibleForTesting
+  public static void enableSymlinks() {
+    symlinksEnabled = true;
+  }
 }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileSystemLinkResolver.java

@@ -87,6 +87,10 @@ public T resolve(final FileSystem filesys, final Path path)
               + CommonConfigurationKeys.FS_CLIENT_RESOLVE_REMOTE_SYMLINKS_KEY
               + ").", e);
         }
+        if (!FileSystem.areSymlinksEnabled()) {
+          throw new IOException("Symlink resolution is disabled in" +
+              " this version of Hadoop.");
+        }
         if (count++ > FsConstants.MAX_PATH_LINKS) {
           throw new IOException("Possible cyclic loop while " +
                                 "following symbolic link " + path);

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/RawLocalFileSystem.java

@@ -775,9 +775,13 @@ public boolean supportsSymlinks() {
     return true;
   }
 
+  @SuppressWarnings("deprecation")
   @Override
   public void createSymlink(Path target, Path link, boolean createParent)
       throws IOException {
+    if (!FileSystem.areSymlinksEnabled()) {
+      throw new UnsupportedOperationException("Symlinks not supported");
+    }
     final String targetScheme = target.toUri().getScheme();
     if (targetScheme != null && !"file".equals(targetScheme)) {
       throw new IOException("Unable to create symlink to non-local file "+

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/SymlinkBaseTest.java

@@ -36,6 +36,10 @@
  * Base test for symbolic links
  */
 public abstract class SymlinkBaseTest {
+  // Re-enable symlinks for tests, see HADOOP-10020 and HADOOP-10052
+  static {
+    FileSystem.enableSymlinks();
+  }
   static final long seed = 0xDEADBEEFL;
   static final int  blockSize =  8192;
   static final int  fileSize  = 16384;

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestFileContextResolveAfs.java

@@ -31,7 +31,9 @@
  * Tests resolution of AbstractFileSystems for a given path with symlinks.
  */
 public class TestFileContextResolveAfs {
-  
+  static {
+    FileSystem.enableSymlinks();
+  }
   private static String TEST_ROOT_DIR_LOCAL
     = System.getProperty("test.build.data","/tmp");
   

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestStat.java

@@ -32,7 +32,9 @@
 import org.junit.Test;
 
 public class TestStat extends FileSystemTestHelper {
-
+  static {
+    FileSystem.enableSymlinks();
+  }
   private static Stat stat;
 
   @BeforeClass

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java

@@ -1286,12 +1286,16 @@ public FileStatus next(final FileSystem fs, final Path p)
     }.resolve(this, absF);
   }
 
+  @SuppressWarnings("deprecation")
   @Override
   public void createSymlink(final Path target, final Path link,
       final boolean createParent) throws AccessControlException,
       FileAlreadyExistsException, FileNotFoundException,
       ParentNotDirectoryException, UnsupportedFileSystemException, 
       IOException {
+    if (!FileSystem.areSymlinksEnabled()) {
+      throw new UnsupportedOperationException("Symlinks not supported");
+    }
     statistics.incrementWriteOps(1);
     final Path absF = fixRelativePart(link);
     new FileSystemLinkResolver<Void>() {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java

@@ -33,6 +33,7 @@
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.XAttrSetFlag;
 import org.apache.hadoop.hdfs.protocol.HdfsConstantsClient;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
@@ -630,6 +631,9 @@ fsDir, renameReservedPathsOnUpgrade(timesOp.path, logVersion),
       break;
     }
     case OP_SYMLINK: {
+      if (!FileSystem.areSymlinksEnabled()) {
+        throw new IOException("Symlinks not supported - please remove symlink before upgrading to this version of HDFS");
+      }
       SymlinkOp symlinkOp = (SymlinkOp)op;
       inodeId = getAndUpdateLastInodeId(symlinkOp.inodeId, logVersion,
           lastInodeId);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImageFormat.java

@@ -42,6 +42,7 @@
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.PathIsNotDirectoryException;
 import org.apache.hadoop.fs.UnresolvedLinkException;
@@ -723,6 +724,7 @@ public INode loadINodeWithLocalName(boolean isSnapshotINode,
    * @param counter Counter to increment for namenode startup progress
    * @return an inode
    */
+  @SuppressWarnings("deprecation")
   INode loadINode(final byte[] localName, boolean isSnapshotINode,
       DataInput in, Counter counter) throws IOException {
     final int imgVersion = getLayoutVersion();
@@ -836,6 +838,9 @@ INode loadINode(final byte[] localName, boolean isSnapshotINode,
       return dir;
     } else if (numBlocks == -2) {
       //symlink
+      if (!FileSystem.areSymlinksEnabled()) {
+        throw new IOException("Symlinks not supported - please remove symlink before upgrading to this version of HDFS");
+      }
 
       final String symlink = Text.readString(in);
       final PermissionStatus permissions = PermissionStatus.read(in);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -147,6 +147,7 @@
 import org.apache.hadoop.fs.FileAlreadyExistsException;
 import org.apache.hadoop.fs.FileEncryptionInfo;
 import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.FsServerDefaults;
 import org.apache.hadoop.fs.InvalidPathException;
 import org.apache.hadoop.fs.Options;
@@ -2131,6 +2132,9 @@ boolean shouldCopyOnTruncate(INodeFile file, BlockInfoContiguous blk) {
   void createSymlink(String target, String link,
       PermissionStatus dirPerms, boolean createParent, boolean logRetryCache)
       throws IOException {
+    if (!FileSystem.areSymlinksEnabled()) {
+      throw new UnsupportedOperationException("Symlinks not supported");
+    }
     waitForLoadingFSImage();
     HdfsFileStatus auditStat = null;
     checkOperation(OperationCategory.WRITE);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/MiniDFSCluster.java

@@ -769,6 +769,9 @@ private void initMiniDFSCluster(
     try {
       ExitUtil.disableSystemExit();
 
+      // Re-enable symlinks for tests, see HADOOP-10020 and HADOOP-10052
+      FileSystem.enableSymlinks();
+
       synchronized (MiniDFSCluster.class) {
         instanceId = instanceCount++;
       }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestINodeFile.java

@@ -71,6 +71,10 @@
 import com.google.common.collect.ImmutableList;
 
 public class TestINodeFile {
+  // Re-enable symlinks for tests, see HADOOP-10020 and HADOOP-10052
+  static {
+    FileSystem.enableSymlinks();
+  }
   public static final Log LOG = LogFactory.getLog(TestINodeFile.class);
 
   static final short BLOCKBITS = 48;