HDFS-17602. RBF mount point with SPACE order can not find the most available namespace, it will choose an irrelevant namespace

Author: wzk784533

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/resolver/order/AvailableSpaceResolver.java

@@ -22,10 +22,12 @@
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Random;
+import java.util.Set;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.server.federation.resolver.PathLocation;
@@ -118,6 +120,19 @@ protected String chooseFirstNamespace(String path, PathLocation loc) {
         getSubclusterMapping();
     List<SubclusterAvailableSpace> subclusterList = new LinkedList<>(
         subclusterInfo.values());
+    if (loc != null && loc.getDestinations() != null) {
+        Set<String> locSet = new HashSet<String>();
+        for (RemoteLocation dest : loc.getDestinations()) {
+            locSet.add(dest.getNameserviceId());
+        }
+        List<SubclusterAvailableSpace> filteredSubclusterList = new LinkedList<>();
+        for (SubclusterAvailableSpace cluster : subclusterList) {
+            if (locSet.contains(cluster.getNameserviceId())) {
+                filteredSubclusterList.add(cluster);
+            }
+        }
+        subclusterList = filteredSubclusterList;
+    }
     Collections.sort(subclusterList, comparator);
 
     return subclusterList.size() > 0 ? subclusterList.get(0).getNameserviceId()