nfs: remove deviceid to data server mapping when pool is removed

Motivation:
When mapping between pool name and IP address is removed, we ween to
remove remove corresponding mapping for device id as well.

Modification:
remove devide id -> data server mapping when pool is removed

Result:
no dangling device ids

Acked-by: Paul Millar
Target: master
Require-book: no
Require-notes: no

modules/dcache-nfs/src/main/java/org/dcache/chimera/nfsv41/door/PoolDeviceMap.java

@@ -107,7 +107,11 @@ Collection<Map.Entry<String,PoolDS>> getEntries() {
     PoolDS remove(String pool) {
         _wlock.lock();
         try {
-            return _poolNameToIpMap.remove(pool);
+            PoolDS ds = _poolNameToIpMap.remove(pool);
+            if (ds != null) {
+                _deviceMap.remove(ds.getDeviceId());
+            }
+            return ds;
         } finally {
             _wlock.unlock();
         }

modules/dcache-nfs/src/test/java/org/dcache/chimera/nfsv41/door/PoolDeviceMapTest.java

@@ -3,12 +3,12 @@
 import java.net.InetSocketAddress;
 import java.net.UnknownHostException;
 import org.dcache.nfs.v4.xdr.deviceid4;
-import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertSame;
 
 public class PoolDeviceMapTest {
 
@@ -43,6 +43,16 @@ public void testUpdateExisting() throws UnknownHostException {
         InetSocketAddress[] ip = new InetSocketAddress[]{new InetSocketAddress(0)};
 
         NFSv41Door.PoolDS ds = _poolDeviceMap.getOrCreateDS(name, 0, ip);
-        Assert.assertSame(ds, _poolDeviceMap.getOrCreateDS(name, 0, ip));
+        assertSame(ds, _poolDeviceMap.getOrCreateDS(name, 0, ip));
+    }
+
+    @Test
+    public void testRemoveExisting() throws UnknownHostException {
+        String name = "somePool";
+        InetSocketAddress[] ip = new InetSocketAddress[]{new InetSocketAddress(0)};
+
+        NFSv41Door.PoolDS ds = _poolDeviceMap.getOrCreateDS(name, 0, ip);
+        _poolDeviceMap.remove(name);
+        assertNull("Removed pool stil available", _poolDeviceMap.getByDeviceId(ds.getDeviceId()));
     }
 }