HDFS-13253. RBF: Quota management incorrect parent-child relationship judgement. Contributed by Yiqun Lin.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/resolver/MountTableResolver.java

@@ -20,6 +20,7 @@
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_ROUTER_DEFAULT_NAMESERVICE;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.FEDERATION_MOUNT_TABLE_MAX_CACHE_SIZE;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.FEDERATION_MOUNT_TABLE_MAX_CACHE_SIZE_DEFAULT;
+import static org.apache.hadoop.hdfs.server.federation.router.FederationUtil.isParentEntry;
 
 import java.io.IOException;
 import java.util.Collection;
@@ -239,7 +240,7 @@ private void invalidateLocationCache(final String path) {
       PathLocation loc = entry.getValue();
       String src = loc.getSourcePath();
       if (src != null) {
-        if (src.startsWith(path)) {
+        if(isParentEntry(src, path)) {
           LOG.debug("Removing {}", src);
           it.remove();
         }
@@ -530,17 +531,6 @@ public String getDefaultNamespace() {
     return this.defaultNameService;
   }
 
-  private boolean isParentEntry(final String path, final String parent) {
-    if (!path.startsWith(parent)) {
-      return false;
-    }
-    if (path.equals(parent)) {
-      return true;
-    }
-    return path.charAt(parent.length()) == Path.SEPARATOR_CHAR
-        || parent.equals(Path.SEPARATOR);
-  }
-
   /**
    * Find the deepest mount point for a path.
    * @param path Path to look for.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/router/FederationUtil.java

@@ -26,6 +26,7 @@
 import java.net.URLConnection;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.server.federation.resolver.ActiveNamenodeResolver;
 import org.apache.hadoop.hdfs.server.federation.resolver.FileSubclusterResolver;
@@ -186,4 +187,23 @@ public static ActiveNamenodeResolver newActiveNamenodeResolver(
         ActiveNamenodeResolver.class);
     return newInstance(conf, stateStore, StateStoreService.class, clazz);
   }
+
+  /**
+   * Check if the given path is the child of parent path.
+   * @param path Path to be check.
+   * @param parent Parent path.
+   * @return True if parent path is parent entry for given path.
+   */
+  public static boolean isParentEntry(final String path, final String parent) {
+    if (!path.startsWith(parent)) {
+      return false;
+    }
+
+    if (path.equals(parent)) {
+      return true;
+    }
+
+    return path.charAt(parent.length()) == Path.SEPARATOR_CHAR
+        || parent.equals(Path.SEPARATOR);
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterQuotaManager.java

@@ -17,6 +17,9 @@
  */
 package org.apache.hadoop.hdfs.server.federation.router;
 
+import static org.apache.hadoop.hdfs.server.federation.router.FederationUtil.isParentEntry;
+
+import java.util.HashSet;
 import java.util.Set;
 import java.util.SortedMap;
 import java.util.TreeMap;
@@ -94,7 +97,16 @@ public Set<String> getPaths(String parentPath) {
       String from = parentPath;
       String to = parentPath + Character.MAX_VALUE;
       SortedMap<String, RouterQuotaUsage> subMap = this.cache.subMap(from, to);
-      return subMap.keySet();
+
+      Set<String> validPaths = new HashSet<>();
+      if (subMap != null) {
+        for (String path : subMap.keySet()) {
+          if (isParentEntry(path, parentPath)) {
+            validPaths.add(path);
+          }
+        }
+      }
+      return validPaths;
     } finally {
       readLock.unlock();
     }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterQuotaManager.java

@@ -57,6 +57,18 @@ public void testGetChildrenPaths() {
     assertTrue(childrenPaths.contains("/path1/subdir")
         && childrenPaths.contains("/path1/subdir/subdir")
         && childrenPaths.contains("/path1"));
+
+    // test for corner case
+    manager.put("/path3", quotaUsage);
+    manager.put("/path3/subdir", quotaUsage);
+    manager.put("/path3-subdir", quotaUsage);
+
+    childrenPaths = manager.getPaths("/path3");
+    assertEquals(2, childrenPaths.size());
+    // path /path3-subdir should not be returned
+    assertTrue(childrenPaths.contains("/path3")
+        && childrenPaths.contains("/path3/subdir")
+        && !childrenPaths.contains("/path3-subdir"));
   }
 
   @Test