nfs4: add more delegations test

Motivation:
Better test coverage.

Modification:
Test two read delegations from different clients.

Acked-by: Paul Millar
Target: master

Author: kofemann

core/src/test/java/org/dcache/nfs/v4/FileTrackerTest.java

@@ -239,8 +239,6 @@ public void shouldNotReadDelegation() throws Exception {
     public void shouldReCallReadDelegationOnConflict() throws Exception {
 
         NFS4Client client = createClient(sh);
-        ClientCB mockCallBack = mock(ClientCB.class);
-        client.setCB(mockCallBack);
 
         StateOwner stateOwner1 = client.getOrCreateOwner("client1".getBytes(StandardCharsets.UTF_8), new seqid4(0));
         StateOwner stateOwner2 = client.getOrCreateOwner("client2".getBytes(StandardCharsets.UTF_8), new seqid4(0));
@@ -257,7 +255,25 @@ public void shouldReCallReadDelegationOnConflict() throws Exception {
             // expected
         }
 
-        verify(mockCallBack).cbDelegationRecall(any(), any(), anyBoolean());
+        verify(client.getCB()).cbDelegationRecall(any(), any(), anyBoolean());
     }
 
+    @Test
+    public void shouldAllowMultipleReadDelegation() throws Exception {
+
+        NFS4Client client1 = createClient(sh);
+        NFS4Client client2 = createClient(sh);
+
+        StateOwner stateOwner1 = client1.getOrCreateOwner("client1".getBytes(StandardCharsets.UTF_8), new seqid4(0));
+        StateOwner stateOwner2 = client2.getOrCreateOwner("client2".getBytes(StandardCharsets.UTF_8), new seqid4(0));
+
+        nfs_fh4 fh = generateFileHandle();
+        Inode inode = Inode.forFile(fh.value);
+
+        var openRecord1 = tracker.addOpen(client1, stateOwner1, inode, OPEN4_SHARE_ACCESS_READ | nfs4_prot.OPEN4_SHARE_ACCESS_WANT_READ_DELEG, 0);
+        var openRecord2 = tracker.addOpen(client2, stateOwner2, inode, OPEN4_SHARE_ACCESS_READ | nfs4_prot.OPEN4_SHARE_ACCESS_WANT_READ_DELEG, 0);
+
+        assertTrue("Read delegation not granted", openRecord2.hasDelegation());
+
+    }
 }

core/src/test/java/org/dcache/nfs/v4/NfsTestUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009 - 2020 Deutsches Elektronen-Synchroton,
+ * Copyright (c) 2009 - 2025 Deutsches Elektronen-Synchroton,
  * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY
  *
  * This library is free software; you can redistribute it and/or modify
@@ -66,7 +66,12 @@ static NFS4Client createClient(NFSv4StateHandler stateHandler, int minor) throws
         byte[] bootTime = new byte[8];
         RANDOM.nextBytes(owner);
         Bytes.putLong(bootTime, 0, System.currentTimeMillis());
-        return stateHandler.createClient(address, address, minor, owner, new verifier4(bootTime), null, false);
+
+        ClientCB mockCallBack = mock(ClientCB.class);
+        var client =  stateHandler.createClient(address, address, minor, owner, new verifier4(bootTime), null, false);
+        client.setCB(mockCallBack);
+
+        return client;
     }
 
     public static COMPOUND4res executeWithStatus(CompoundContext context, COMPOUND4args args, int expectedStatus) throws IOException {