[PATCH 4/4] nvme: check that EUI/GUID/UUID are globally unique

[Alan Adamson]

> On Jun 21, 2022, at 12:11 PM, Keith Busch <kbusch at kernel.org> wrote:
> 
> On Tue, Jun 21, 2022 at 06:40:49PM +0000, Alan Adamson wrote:
>> +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;
>> +
>> +	if (!ctrl->subsys->clear_ids)
>> +		return status;
>> +
>> +	data = kzalloc(NVME_IDENTIFY_DATA_SIZE, GFP_KERNEL);
>> +	if (!data)
>> +		return NVME_SC_INTERNAL;
>> +
>> +	status = nvmet_copy_from_sgl(req, 0, data, NVME_IDENTIFY_DATA_SIZE);
>> +	if (status)
>> +		goto out_free;
>> +
>> +	for (pos = 0; pos < NVME_IDENTIFY_DATA_SIZE; pos += len) {
>> +		cur = data + pos;
>> +
>> +		if (cur->nidl == 0)
>> +			break;
>> +		len = cur->nidl;
>> +		if (cur->nidt == NVME_NIDT_CSI) {
>> +			memcpy(&csi, data + pos + sizeof(struct nvme_ns_id_desc), NVME_NIDT_CSI_LEN);
>> +			csi_seen = 1;
>> +			break;
>> +		}
>> +		len += sizeof(struct nvme_ns_id_desc);
>> +	}
>> +	if (csi_seen) {
>> +		cur = data;
>> +		cur->nidt = NVME_NIDT_CSI;
>> +		cur->nidl = NVME_NIDT_CSI_LEN;
>> +		memcpy(data + sizeof(struct nvme_ns_id_desc), &csi,  NVME_NIDT_CSI_LEN);
>> +
>> +		cur = data + sizeof(struct nvme_ns_id_desc) + NVME_NIDT_CSI_LEN;
>> +		cur->nidt = 0;
>> +		cur->nidl = 0;
>> +		status = nvmet_copy_to_sgl(req, 0, data, NVME_IDENTIFY_DATA_SIZE);
>> +	}
> 
> This is clearing the other descriptors only if the controller also reports a
> CSI field. I think just do something like the following on top of your patch,
> and should be good to go.
> 
> ---
> diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c
> index f863cd459652..f9599b0cd129 100644
> --- a/drivers/nvme/target/passthru.c
> +++ b/drivers/nvme/target/passthru.c
> @@ -54,17 +54,15 @@ static u16 nvmet_passthru_override_id_descs(struct nvmet_req *req)
> 		}
> 		len += sizeof(struct nvme_ns_id_desc);
> 	}
> +
> +	memset(data, 0, NVME_IDENTIFY_DATA_SIZE);
> 	if (csi_seen) {
> 		cur = data;
> 		cur->nidt = NVME_NIDT_CSI;
> 		cur->nidl = NVME_NIDT_CSI_LEN;
> 		memcpy(data + sizeof(struct nvme_ns_id_desc), &csi,  NVME_NIDT_CSI_LEN);
> -
> -		cur = data + sizeof(struct nvme_ns_id_desc) + NVME_NIDT_CSI_LEN;
> -		cur->nidt = 0;
> -		cur->nidl = 0;
> -		status = nvmet_copy_to_sgl(req, 0, data, NVME_IDENTIFY_DATA_SIZE);
> 	}
> +	status = nvmet_copy_to_sgl(req, 0, data, NVME_IDENTIFY_DATA_SIZE);
> out_free:
> 	kfree(data);
> 	return status;
> --

Yes I can do that.  Originally I was doing that, but wanted to avoid the 4K copy of zeros.

Thanks,

Alan