nfsv41: fix expired client session recovery

observed with RHEL 6.2

at some point client sends late SEQUENCE.
Server reply with NFS4ERR_EXPIRED. Client
attempts to establish a new session, but uses
old client id. Due to a bug in recovery procedure
This ends up with EXPIRED as well.

src/org/dcache/chimera/nfs/v4/NFS4Client.java

@@ -210,8 +210,8 @@ public class NFS4Client {
         _isConfirmed = true;
     }
 
-    public long leaseTime() {
-        return _cl_time;
+    public boolean isLeaseValid() {
+        return (System.currentTimeMillis() - _cl_time) > _leaseTime;
     }
 
     /**

src/org/dcache/chimera/nfs/v4/OperationEXCHANGE_ID.java

@@ -190,22 +190,23 @@ public class OperationEXCHANGE_ID extends AbstractNFSv4Operation {
                 if (client.isConfirmed()) {
                     if (client.verifierEquals(verifier) && principal.equals(client.principal())) {
                         _log.debug("Case 2: Non-Update on Existing Client ID");
+                        if (!client.hasState()) {
+                            client.refreshLeaseTime();
+                        }                        
                     } else if (principal.equals(client.principal())) {
-
                         _log.debug("case 5: Client Restart");
                         context.getStateHandler().removeClient(client);
                         client = context.getStateHandler().createClient(
                                 remoteSocketAddress, localSocketAddress,
                                 clientOwner, _args.opexchange_id.eia_clientowner.co_verifier, principal);
                     } else {
-                        if ((!client.hasState()) || (System.currentTimeMillis() - client.leaseTime()) > (NFSv4Defaults.NFS4_LEASE_TIME * 1000)) {
-                            _log.debug("case 3a: Client Collision is equivalent to case 1 (the new Owner ID)");
+                        _log.debug("Case 3b: Client Collision");
+                        if ((!client.hasState()) || !client.isLeaseValid()) {
                             context.getStateHandler().removeClient(client);
                             client = context.getStateHandler().createClient(
                                     remoteSocketAddress, localSocketAddress,
                                     clientOwner, _args.opexchange_id.eia_clientowner.co_verifier, principal);
                         } else {
-                            _log.debug("Case 3b: Client Collision");
                             throw new ChimeraNFSException(nfsstat.NFSERR_CLID_INUSE, "Principal Missmatch");
                         }
                     }

test/org/dcache/chimera/nfs/v4/OperationEXCHANGE_IDTest.java

@@ -17,9 +17,11 @@
 package org.dcache.chimera.nfs.v4;
 
 import java.util.UUID;
+import java.util.concurrent.TimeUnit;
 import org.dcache.chimera.nfs.nfsstat;
 import org.dcache.chimera.nfs.v4.client.CreateSessionStub;
 import org.dcache.chimera.nfs.v4.client.ExchangeIDStub;
+import org.dcache.chimera.nfs.v4.client.SequenceStub;
 import org.dcache.chimera.nfs.v4.xdr.*;
 import org.junit.Before;
 import org.junit.Test;
@@ -33,7 +35,7 @@ public class OperationEXCHANGE_IDTest {
 
     @Before
     public void setUp() {
-        stateHandler = new NFSv4StateHandler();
+        stateHandler = new NFSv4StateHandler(2000);
         clientId = UUID.randomUUID().toString();
     }
 
@@ -136,4 +138,46 @@ public class OperationEXCHANGE_IDTest {
          result = nfs_resop4.resopFor(nfs_opnum4.OP_EXCHANGE_ID);
          AssertNFS.assertNFS(EXCHANGE_ID, context, result, nfsstat.NFS_OK);
     }
+
+    @Test
+    public void testResendConfirmedLate() throws Exception {
+        CompoundContext context;
+        nfs_resop4 result;
+
+        nfs_argop4 exchangeid_args = ExchangeIDStub.normal(domain, name, clientId, 0, state_protect_how4.SP4_NONE);
+        OperationEXCHANGE_ID EXCHANGE_ID = new OperationEXCHANGE_ID(exchangeid_args, 0);
+
+        result = nfs_resop4.resopFor(nfs_opnum4.OP_EXCHANGE_ID);
+        context = new CompoundContextBuilder()
+                .withStateHandler(stateHandler)
+                .withOpCount(1)
+                .build();
+
+        AssertNFS.assertNFS(EXCHANGE_ID, context, result, nfsstat.NFS_OK);
+
+        nfs_argop4 cretaesession_args = CreateSessionStub.standard(
+                result.opexchange_id.eir_resok4.eir_clientid, result.opexchange_id.eir_resok4.eir_sequenceid);
+
+        OperationCREATE_SESSION CREATE_SESSION = new OperationCREATE_SESSION(cretaesession_args);
+        result = nfs_resop4.resopFor(nfs_opnum4.OP_CREATE_SESSION);
+        context = new CompoundContextBuilder()
+                .withStateHandler(stateHandler)
+                .withOpCount(1)
+                .build();
+
+         AssertNFS.assertNFS(CREATE_SESSION, context, result, nfsstat.NFS_OK);
+
+         TimeUnit.SECONDS.sleep(3);
+
+         nfs_argop4 sequence_args = SequenceStub.generateRequest(false,
+                 result.opcreate_session.csr_resok4.csr_sessionid.value, 0, 0, 0);
+
+         OperationSEQUENCE SEQUENCE = new OperationSEQUENCE(sequence_args);
+         result = nfs_resop4.resopFor(nfs_opnum4.OP_SEQUENCE);
+         AssertNFS.assertNFS(SEQUENCE, context, result, nfsstat.NFSERR_EXPIRED);
+
+         EXCHANGE_ID = new OperationEXCHANGE_ID(exchangeid_args, 0);
+         result = nfs_resop4.resopFor(nfs_opnum4.OP_EXCHANGE_ID);
+         AssertNFS.assertNFS(EXCHANGE_ID, context, result, nfsstat.NFS_OK);
+    }
 }