JSF: Cancel datatable row edit after data submission in Primefaces - jsf

Question

I'm developing a web-app in JSF 2.1 + Primefaces 5.1. I have a datatable with editable rows. I catch the rowEdit event and call a DB procedure to do some validations of the new data and update the record when the user clicks the "check" button. But there's a problem: the datatable row in the GUI is updated whether the validations succeed or fail. I want the changes in the row data to be reversed to their previous state if the validations done in the DB procedure fail. How can I do that?
<p:dataTable id="users_table_id" var="user" value="#{usersBean.users}" rowKey="#{user.id}" paginator="true"
paginatorTemplate="{CurrentPageReport} {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}"
rowsPerPageTemplate="5,10,15" emptyMessage="#{msgs.no_records}" sortBy="#{user.id}" sortOrder="ascending" rows="15" editable="true">
<f:facet name="header">
#{msgs.users}
</f:facet>
<p:ajax event="rowEdit" listener="#{usersBean.onRowEdit}"/>
<p:ajax event="rowEditInit" listener="#{usersBean.onRowEditInit}"/>
<p:column headerText="#{msgs.id}" sortBy="#{user.id}" styleClass="centered-column">
#{user.id}
</p:column>
<p:column headerText="#{msgs.description}" sortBy="#{user.description}" styleClass="centered-column">
<p:cellEditor>
<f:facet name="output">#{user.description}</f:facet>
<f:facet name="input"><p:inputText value="#{user.description}" styleClass="editable-cell"/></f:facet>
</p:cellEditor>
</p:column>
...
<p:column styleClass="datatable-row-editor">
<p:rowEditor/>
</p:column>
</p:dataTable>
#ManagedBean
#ViewScoped
public class UsersBean implements Serializable {
private List<DtoUser> users;
public void onRowEdit(RowEditEvent event) {
logger.entry();
DtoUser dtoUser = (DtoUser)event.getObject();
this.updateUser(dtoUser);
logger.exit();
}
public void updateUser(DtoUser dtoUser) {
try {
logger.entry(dtoUser);
DtoBoUsers dtoBoUsers = dtoUser.toDtoBoUsers();
DtoTypeGenericResponse genericResponse = usersService.updateUser(dtoBoUsers);
if (genericResponse.isError()) {
// error in user update
} else {
// update successful
}
logger.exit(dtoUser);
} catch (Exception e) {
logger.error(ExceptionUtils.getStackTrace(e.fillInStackTrace()));
}
}
}