K 10 svn:author V 3 mav K 8 svn:date V 27 2019-08-28T20:58:24.788638Z K 7 svn:log V 271 MFC r351320: Formalize NVMe controller consumer life cycle. This fixes possible double call of fail_fn, for example on hot removal. It also allows ctrlr_fn to safely return NULL cookie in case of failure and not get useless ns_fn or fail_fn call with NULL cookie later. END