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

[Keith Busch]

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;
--