[PATCH 08/14] nvmet: use nvme write cmd group setting op_flag

[Logan Gunthorpe]

On 2020-08-10 5:08 p.m., Chaitanya Kulkarni wrote:
>>> +static inline bool nvmet_write_cmd_group(__u8 opcode)
>>> +{
>>> +	bool ret;
>>> +
>>> +	/* NVM Express Revision 1.4 Figure 462. */
>>> +	switch (opcode) {
>>> +	case nvme_admin_format_nvm:
>>> +	case nvme_admin_ns_attach:
>>> +	case nvme_admin_ns_mgmt:
>>> +	case nvme_admin_sanitize_nvm:
>>> +	case nvme_admin_security_send:
>>
>> All of these admin commands are rejected as INVALID_OPCODE in
>> nvmet_parse_passthru_admin_cmd(). So adding them here seems confusing at
>> best.
>>
> 
> These are extremely important commands, why these commands are
> rejected ?

In some cases we were worried about side effects with other hosts
accessing the namespace, in others they require using the ctrl_id which
isn't really mapped in a sane way.

> What is the use of passthru if host cannot create namespaces format ns 
> and sanitize the important data ?

Plenty, they can format the ns on the native host and still use them on
other targets.

> Irrespective of that it better have it documented there is no harm.

We shouldn't have code that doesn't actually do anything. It's confusing
and bad practice.

Logan