[PATCH] Add new clear_ids attribute for passthru targets

[Alan Adamson]

> On Jun 27, 2022, at 2:00 PM, Chaitanya Kulkarni <chaitanyak at nvidia.com> wrote:
> 
> On 6/22/22 15:47, Alan Adamson wrote:
>> If the clear_ids attribute is set to true, the EUI/GUID/UUID is
>> cleared for the passthru target.  By default, loop targets will
>> set clear_ids to true.
>> 
>> This resolves an issue where a connect to a passthru target fails
>> when using a trtype of 'loop' because EUI/GUID/UUID is not unique.
>> 
>> Signed-off-by: Alan Adamson <alan.adamson at oracle.com>
>> ---
>>  drivers/nvme/target/configfs.c | 20 ++++++++++++
>>  drivers/nvme/target/core.c     |  4 +++
>>  drivers/nvme/target/nvmet.h    |  1 +
>>  drivers/nvme/target/passthru.c | 58 ++++++++++++++++++++++++++++++++++
>>  4 files changed, 83 insertions(+)
>> 
>> diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
>> index e44b2988759e..ff77c3d2354f 100644
>> --- a/drivers/nvme/target/configfs.c
>> +++ b/drivers/nvme/target/configfs.c
>> @@ -773,11 +773,31 @@ static ssize_t nvmet_passthru_io_timeout_store(struct config_item *item,
>>  }
>>  CONFIGFS_ATTR(nvmet_passthru_, io_timeout);
>> 
>> +static ssize_t nvmet_passthru_clear_ids_show(struct config_item *item,
>> +		char *page)
>> +{
>> +	return sprintf(page, "%u\n", to_subsys(item->ci_parent)->clear_ids);
> 
> should we use snprintf() ? (I don't think so just a thought.

I used sprintf() to be consistent with the other passthru attributes.  

>> 
>> +static u16 nvmet_passthru_override_id_descs(struct nvmet_req *req)
>> +{
>> +	struct nvmet_ctrl *ctrl = req->sq->ctrl;
>> +	void *data;
>> +	struct nvme_ns_id_desc *cur;
>> +	u16 status = NVME_SC_SUCCESS;
>> +	u8 csi;
>> +	int pos, len;
>> +	bool csi_seen;
>> +
> 
> consider followig if it works, totally untested :-
> 
>        struct nvmet_ctrl *ctrl = req->sq->ctrl;
>        struct nvme_ns_id_desc *cur;
>        u16 status = NVME_SC_SUCCESS;
>        int pos, len;
>        bool csi_seen;
>        void *data;
>        u8 csi;

I'll include these changes in v2.

>> 
>>  static u16 nvmet_passthru_override_id_ns(struct nvmet_req *req)
>>  {
>> +	struct nvmet_ctrl *ctrl = req->sq->ctrl;
> 
> since ctrl is only used once in this function do can we get away with
> the req->sq->ctrl->subsys->clear_ids ?

I’ll include in v2.

>> 
> 
> Irrespective of cosmetics, looks good.
> 
> Reviewed-by: Chaitanya Kulkarni <kch at nvidia.com>
> 
> -ck
> 

Thanks,

Alan