rxrpc: The client call state must be changed before attachment to conn

We must set the client call state to RXRPC_CALL_CLIENT_SEND_REQUEST before
attaching the call to the connection struct, not after, as it's liable to
receive errors and conn aborts as soon as the assignment is made - and
these will cause its state to be changed outside of the initiating thread's
control.
Signed-off-by: David Howells <dhowells@redhat.com>

net/rxrpc/call_object.c

@@ -197,8 +197,6 @@ static int rxrpc_begin_client_call(struct rxrpc_call *call,
 	if (ret < 0)
 		return ret;
 
-	call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
-
 	spin_lock(&call->conn->params.peer->lock);
 	hlist_add_head(&call->error_link, &call->conn->params.peer->error_targets);
 	spin_unlock(&call->conn->params.peer->lock);

net/rxrpc/conn_client.c

@@ -537,6 +537,10 @@ static void rxrpc_activate_one_channel(struct rxrpc_connection *conn,
 					     struct rxrpc_call, chan_wait_link);
 	u32 call_id = chan->call_counter + 1;
 
+	write_lock_bh(&call->state_lock);
+	call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
+	write_unlock_bh(&call->state_lock);
+
 	rxrpc_see_call(call);
 	list_del_init(&call->chan_wait_link);
 	conn->active_chans |= 1 << channel;