HDFS-7420. Delegate permission checks to FSDirectory. Contributed by Haohui Mai.

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -383,6 +383,8 @@ Release 2.7.0 - UNRELEASED
 
     HDFS-7415. Move FSNameSystem.resolvePath() to FSDirectory. (wheat9)
 
+    HDFS-7420. Delegate permission checks to FSDirectory. (wheat9)
+
   OPTIMIZATIONS
 
   BUG FIXES

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

@@ -52,6 +52,7 @@ import org.apache.hadoop.fs.XAttr;
 import org.apache.hadoop.fs.XAttrSetFlag;
 import org.apache.hadoop.fs.permission.AclEntry;
 import org.apache.hadoop.fs.permission.AclStatus;
+import org.apache.hadoop.fs.permission.FsAction;
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.fs.permission.PermissionStatus;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
@@ -96,6 +97,7 @@ import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
 import org.apache.hadoop.security.AccessControlException;
+import org.apache.hadoop.security.UserGroupInformation;
 
 /**
  * Both FSDirectory and FSNamesystem manage the state of the namespace.
@@ -152,6 +154,8 @@ public class FSDirectory implements Closeable {
   private final ReentrantReadWriteLock dirLock;
 
   private final boolean isPermissionEnabled;
+  private final String fsOwnerShortUserName;
+  private final String supergroup;
 
   // utility methods to acquire and release read lock and write lock
   void readLock() {
@@ -195,13 +199,19 @@ public class FSDirectory implements Closeable {
    */
   private final NameCache<ByteArray> nameCache;
 
-  FSDirectory(FSNamesystem ns, Configuration conf) {
+  FSDirectory(FSNamesystem ns, Configuration conf) throws IOException {
     this.dirLock = new ReentrantReadWriteLock(true); // fair
     rootDir = createRoot(ns);
     inodeMap = INodeMap.newInstance(rootDir);
     this.isPermissionEnabled = conf.getBoolean(
       DFSConfigKeys.DFS_PERMISSIONS_ENABLED_KEY,
       DFSConfigKeys.DFS_PERMISSIONS_ENABLED_DEFAULT);
+    this.fsOwnerShortUserName =
+      UserGroupInformation.getCurrentUser().getShortUserName();
+    this.supergroup = conf.get(
+      DFSConfigKeys.DFS_PERMISSIONS_SUPERUSERGROUP_KEY,
+      DFSConfigKeys.DFS_PERMISSIONS_SUPERUSERGROUP_DEFAULT);
+
     int configuredLimit = conf.getInt(
         DFSConfigKeys.DFS_LIST_LIMIT, DFSConfigKeys.DFS_LIST_LIMIT_DEFAULT);
     this.lsLimit = configuredLimit>0 ?
@@ -3331,4 +3341,76 @@ public class FSDirectory implements Closeable {
     }
     return inodesInPath;
   }
+
+  FSPermissionChecker getPermissionChecker()
+    throws AccessControlException {
+    try {
+      return new FSPermissionChecker(fsOwnerShortUserName, supergroup,
+          NameNode.getRemoteUser());
+    } catch (IOException ioe) {
+      throw new AccessControlException(ioe);
+    }
+  }
+
+  void checkOwner(FSPermissionChecker pc, String path)
+      throws AccessControlException, UnresolvedLinkException {
+    checkPermission(pc, path, true, null, null, null, null);
+  }
+
+  void checkPathAccess(FSPermissionChecker pc, String path,
+                       FsAction access)
+      throws AccessControlException, UnresolvedLinkException {
+    checkPermission(pc, path, false, null, null, access, null);
+  }
+  void checkParentAccess(
+      FSPermissionChecker pc, String path, FsAction access)
+      throws AccessControlException, UnresolvedLinkException {
+    checkPermission(pc, path, false, null, access, null, null);
+  }
+
+  void checkAncestorAccess(
+      FSPermissionChecker pc, String path, FsAction access)
+      throws AccessControlException, UnresolvedLinkException {
+    checkPermission(pc, path, false, access, null, null, null);
+  }
+
+  void checkTraverse(FSPermissionChecker pc, String path)
+      throws AccessControlException, UnresolvedLinkException {
+    checkPermission(pc, path, false, null, null, null, null);
+  }
+
+  /**
+   * Check whether current user have permissions to access the path. For more
+   * details of the parameters, see
+   * {@link FSPermissionChecker#checkPermission}.
+   */
+  private void checkPermission(
+    FSPermissionChecker pc, String path, boolean doCheckOwner,
+    FsAction ancestorAccess, FsAction parentAccess, FsAction access,
+    FsAction subAccess)
+    throws AccessControlException, UnresolvedLinkException {
+    checkPermission(pc, path, doCheckOwner, ancestorAccess,
+        parentAccess, access, subAccess, false, true);
+  }
+
+  /**
+   * Check whether current user have permissions to access the path. For more
+   * details of the parameters, see
+   * {@link FSPermissionChecker#checkPermission}.
+   */
+  void checkPermission(
+      FSPermissionChecker pc, String path, boolean doCheckOwner,
+      FsAction ancestorAccess, FsAction parentAccess, FsAction access,
+      FsAction subAccess, boolean ignoreEmptyDir, boolean resolveLink)
+      throws AccessControlException, UnresolvedLinkException {
+    if (!pc.isSuperUser()) {
+      readLock();
+      try {
+        pc.checkPermission(path, this, doCheckOwner, ancestorAccess,
+            parentAccess, access, subAccess, ignoreEmptyDir, resolveLink);
+      } finally {
+        readUnlock();
+      }
+    }
+  }
 }

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

@@ -404,7 +404,6 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
   static int BLOCK_DELETION_INCREMENT = 1000;
   private final boolean isPermissionEnabled;
   private final UserGroupInformation fsOwner;
-  private final String fsOwnerShortUserName;
   private final String supergroup;
   private final boolean standbyShouldCheckpoint;
   
@@ -777,7 +776,6 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
                           DFS_STORAGE_POLICY_ENABLED_DEFAULT);
 
       this.fsOwner = UserGroupInformation.getCurrentUser();
-      this.fsOwnerShortUserName = fsOwner.getShortUserName();
       this.supergroup = conf.get(DFS_PERMISSIONS_SUPERUSERGROUP_KEY, 
                                  DFS_PERMISSIONS_SUPERUSERGROUP_DEFAULT);
       this.isPermissionEnabled = conf.getBoolean(DFS_PERMISSIONS_ENABLED_KEY,
@@ -3922,11 +3920,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
     
   private FSPermissionChecker getPermissionChecker()
       throws AccessControlException {
-    try {
-      return new FSPermissionChecker(fsOwnerShortUserName, supergroup, getRemoteUser());
-    } catch (IOException ioe) {
-      throw new AccessControlException(ioe);
-    }
+    return dir.getPermissionChecker();
   }
   
   /**
@@ -6411,13 +6405,13 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
 
   private void checkOwner(FSPermissionChecker pc, String path)
       throws AccessControlException, UnresolvedLinkException {
-    checkPermission(pc, path, true, null, null, null, null);
+    dir.checkOwner(pc, path);
   }
 
   private void checkPathAccess(FSPermissionChecker pc,
       String path, FsAction access) throws AccessControlException,
       UnresolvedLinkException {
-    checkPermission(pc, path, false, null, null, access, null);
+    dir.checkPathAccess(pc, path, access);
   }
 
   private void checkUnreadableBySuperuser(FSPermissionChecker pc,
@@ -6438,18 +6432,18 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
   private void checkParentAccess(FSPermissionChecker pc,
       String path, FsAction access) throws AccessControlException,
       UnresolvedLinkException {
-    checkPermission(pc, path, false, null, access, null, null);
+    dir.checkParentAccess(pc, path, access);
   }
 
   private void checkAncestorAccess(FSPermissionChecker pc,
       String path, FsAction access) throws AccessControlException,
       UnresolvedLinkException {
-    checkPermission(pc, path, false, access, null, null, null);
+    dir.checkAncestorAccess(pc, path, access);
   }
 
   private void checkTraverse(FSPermissionChecker pc, String path)
       throws AccessControlException, UnresolvedLinkException {
-    checkPermission(pc, path, false, null, null, null, null);
+    dir.checkTraverse(pc, path);
   }
 
   @Override
@@ -6474,26 +6468,13 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
             parentAccess, access, subAccess, false, true);
   }
 
-  /**
-   * Check whether current user have permissions to access the path. For more
-   * details of the parameters, see
-   * {@link FSPermissionChecker#checkPermission}.
-   */
   private void checkPermission(FSPermissionChecker pc,
       String path, boolean doCheckOwner, FsAction ancestorAccess,
       FsAction parentAccess, FsAction access, FsAction subAccess,
       boolean ignoreEmptyDir, boolean resolveLink)
       throws AccessControlException, UnresolvedLinkException {
-    if (!pc.isSuperUser()) {
-      waitForLoadingFSImage();
-      readLock();
-      try {
-        pc.checkPermission(path, dir, doCheckOwner, ancestorAccess,
-            parentAccess, access, subAccess, ignoreEmptyDir, resolveLink);
-      } finally {
-        readUnlock();
-      }
-    }
+    dir.checkPermission(pc, path, doCheckOwner, ancestorAccess, parentAccess,
+        access, subAccess, ignoreEmptyDir, resolveLink);
   }
   
   /**

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

@@ -75,7 +75,7 @@ public class TestFSPermissionChecker {
   private INodeDirectory inodeRoot;
 
   @Before
-  public void setUp() {
+  public void setUp() throws IOException {
     Configuration conf = new Configuration();
     FSNamesystem fsn = mock(FSNamesystem.class);
     doAnswer(new Answer() {