Re: [PATCH 14/16] nvmet: add metadata/T10-PI support

[James Smart <james.smart@broadcom.com>]

On 5/4/2020 8:57 AM, Max Gurtovoy wrote:
> From: Israel Rukshin <israelr@mellanox.com>
>
> Expose the namespace metadata format when PI is enabled. The user needs
> to enable the capability per subsystem and per port. The other metadata
> properties are taken from the namespace/bdev.
>
> Usage example:
> echo 1 > /config/nvmet/subsystems/${NAME}/attr_pi_enable
> echo 1 > /config/nvmet/ports/${PORT_NUM}/param_pi_enable
>
> Signed-off-by: Israel Rukshin <israelr@mellanox.com>
> Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
> ---
>   drivers/nvme/target/admin-cmd.c   | 26 +++++++++++++++---
>   drivers/nvme/target/configfs.c    | 58 +++++++++++++++++++++++++++++++++++++++
>   drivers/nvme/target/core.c        | 21 +++++++++++---
>   drivers/nvme/target/fabrics-cmd.c |  7 +++--
>   drivers/nvme/target/nvmet.h       | 19 +++++++++++++
>   5 files changed, 121 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
> index 905aba8..9c8a00d 100644
> --- a/drivers/nvme/target/admin-cmd.c
> +++ b/drivers/nvme/target/admin-cmd.c
> @@ -341,6 +341,7 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
>   {
>   	struct nvmet_ctrl *ctrl = req->sq->ctrl;
>   	struct nvme_id_ctrl *id;
> +	u32 cmd_capsule_size;
>   	u16 status = 0;
>   
>   	id = kzalloc(sizeof(*id), GFP_KERNEL);
> @@ -433,9 +434,15 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
>   
>   	strlcpy(id->subnqn, ctrl->subsys->subsysnqn, sizeof(id->subnqn));
>   
> -	/* Max command capsule size is sqe + single page of in-capsule data */
> -	id->ioccsz = cpu_to_le32((sizeof(struct nvme_command) +
> -				  req->port->inline_data_size) / 16);
> +	/*
> +	 * Max command capsule size is sqe + in-capsule data size.
> +	 * Disable in-capsule data for Metadata capable controllers.
> +	 */
> +	cmd_capsule_size = sizeof(struct nvme_command);
> +	if (!ctrl->pi_support)
> +		cmd_capsule_size += req->port->inline_data_size;
> +	id->ioccsz = cpu_to_le32(cmd_capsule_size / 16);
> +

This seems odd to me, and should probably be referencing attributes of 
the a transport, which should probably be set based on what transport 
port the command was received on.


>   	/* Max response capsule size is cqe */
>   	id->iorcsz = cpu_to_le32(sizeof(struct nvme_completion) / 16);
>   
> @@ -465,6 +472,7 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
>   
>   static void nvmet_execute_identify_ns(struct nvmet_req *req)
>   {
> +	struct nvmet_ctrl *ctrl = req->sq->ctrl;
>   	struct nvmet_ns *ns;
>   	struct nvme_id_ns *id;
>   	u16 status = 0;
> @@ -482,7 +490,7 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
>   	}
>   
>   	/* return an all zeroed buffer if we can't find an active namespace */
> -	ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->identify.nsid);
> +	ns = nvmet_find_namespace(ctrl, req->cmd->identify.nsid);
>   	if (!ns)
>   		goto done;
>   
> @@ -526,6 +534,16 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
>   
>   	id->lbaf[0].ds = ns->blksize_shift;
>   
> +	if (ctrl->pi_support && nvmet_ns_has_pi(ns)) {
> +		id->dpc = NVME_NS_DPC_PI_FIRST | NVME_NS_DPC_PI_LAST |
> +			  NVME_NS_DPC_PI_TYPE1 | NVME_NS_DPC_PI_TYPE2 |
> +			  NVME_NS_DPC_PI_TYPE3;

Why is PI_TYPE2 getting set if nvmet_bdev_ns_enable_integrity() won't 
set a metadata size ?

> +		id->mc = NVME_MC_EXTENDED_LBA;
> +		id->dps = ns->pi_type;
> +		id->flbas = NVME_NS_FLBAS_META_EXT;

I guess this is ok - always requiring extended lbas. Will this ever 
change over time ?

> +		id->lbaf[0].ms = ns->metadata_size;
> +	}
> +
>   	if (ns->readonly)
>   		id->nsattr |= (1 << 0);
>   	nvmet_put_namespace(ns);
...
> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
> index 50dfc60..9f6b0f9 100644
> --- a/drivers/nvme/target/core.c
> +++ b/drivers/nvme/target/core.c
> @@ -322,12 +322,21 @@ int nvmet_enable_port(struct nvmet_port *port)
>   	if (!try_module_get(ops->owner))
>   		return -EINVAL;
>   
> -	ret = ops->add_port(port);
> -	if (ret) {
> -		module_put(ops->owner);
> -		return ret;
> +	/*
> +	 * If the user requested PI support and the transport isn't pi capable,
> +	 * don't enable the port.
> +	 */
> +	if (port->pi_enable && !ops->metadata_support) {
> +		pr_err("T10-PI is not supported by transport type %d\n",
> +		       port->disc_addr.trtype);
> +		ret = -EINVAL;
> +		goto out_put;
>   	}
>   
> +	ret = ops->add_port(port);
> +	if (ret)
> +		goto out_put;
> +

ok for now - but it's going to have to be changed later to check the 
port attributes, not the transport ops.  So it'll go back to add_port, 
then validation w/ delete_port if fails.

>   	/* If the transport didn't set inline_data_size, then disable it. */
>   	if (port->inline_data_size < 0)
>   		port->inline_data_size = 0;
> @@ -335,6 +344,10 @@ int nvmet_enable_port(struct nvmet_port *port)
>   	port->enabled = true;
>   	port->tr_ops = ops;
>   	return 0;
> +
> +out_put:
> +	module_put(ops->owner);
> +	return ret;
>   }
>   
>   void nvmet_disable_port(struct nvmet_port *port)
> diff --git a/drivers/nvme/target/fabrics-cmd.c b/drivers/nvme/target/fabrics-cmd.c
> index 52a6f70..42bd12b 100644
> --- a/drivers/nvme/target/fabrics-cmd.c
> +++ b/drivers/nvme/target/fabrics-cmd.c
> @@ -197,6 +197,8 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)
>   		goto out;
>   	}
>   
> +	ctrl->pi_support = ctrl->port->pi_enable && ctrl->subsys->pi_support;
> +
>   	uuid_copy(&ctrl->hostid, &d->hostid);
>   
>   	status = nvmet_install_queue(ctrl, req);
> @@ -205,8 +207,9 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)
>   		goto out;
>   	}
>   
> -	pr_info("creating controller %d for subsystem %s for NQN %s.\n",
> -		ctrl->cntlid, ctrl->subsys->subsysnqn, ctrl->hostnqn);
> +	pr_info("creating controller %d for subsystem %s for NQN %s%s.\n",
> +		ctrl->cntlid, ctrl->subsys->subsysnqn, ctrl->hostnqn,
> +		ctrl->pi_support ? " T10-PI is enabled" : "");
>   	req->cqe->result.u16 = cpu_to_le16(ctrl->cntlid);
>   
>   out:
> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
> index ceedaaf..2986e2c 100644
> --- a/drivers/nvme/target/nvmet.h
> +++ b/drivers/nvme/target/nvmet.h
> @@ -145,6 +145,7 @@ struct nvmet_port {
>   	bool				enabled;
>   	int				inline_data_size;
>   	const struct nvmet_fabrics_ops	*tr_ops;
> +	bool				pi_enable;

ok - but would have liked to have seen this generic-ized for metadata 
support, then PI in the metadata.


-- james




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