NFSv4: Clean up some shutdown loops

If a SEQUENCE call receives -EIO for a shutdown client, it will retry the
RPC call.  Instead of doing that for a shutdown client, just bail out.

Likewise, if the state manager decides to perform recovery for a shutdown
client, it will continuously retry.  As above, just bail out.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/nfs4proc.c

@@ -9371,7 +9371,7 @@ static void nfs41_sequence_call_done(struct rpc_task *task, void *data)
 		return;
 
 	trace_nfs4_sequence(clp, task->tk_status);
-	if (task->tk_status < 0) {
+	if (task->tk_status < 0 && !task->tk_client->cl_shutdown) {
 		dprintk("%s ERROR %d\n", __func__, task->tk_status);
 		if (refcount_read(&clp->cl_count) == 1)
 			return;

fs/nfs/nfs4state.c

@@ -1210,6 +1210,9 @@ void nfs4_schedule_state_manager(struct nfs_client *clp)
 	struct task_struct *task;
 	char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
 
+	if (clp->cl_rpcclient->cl_shutdown)
+		return;
+
 	set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
 	if (test_and_set_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state) != 0) {
 		wake_up_var(&clp->cl_state);