[RFC PATCH v4 11/27] nvme-tcp-offload: Add controller level implementation

Hannes Reinecke hare at suse.de
Sat May 1 17:27:09 BST 2021


On 4/29/21 9:09 PM, Shai Malin wrote:
> From: Arie Gershberg <agershberg at marvell.com>
> 
> In this patch we implement controller level functionality including:
> - create_ctrl.
> - delete_ctrl.
> - free_ctrl.
> 
> The implementation is similar to other nvme fabrics modules, the main
> difference being that the nvme-tcp-offload ULP calls the vendor specific
> claim_dev() op with the given TCP/IP parameters to determine which device
> will be used for this controller.
> Once found, the vendor specific device and controller will be paired and
> kept in a controller list managed by the ULP.
> 
> Acked-by: Igor Russkikh <irusskikh at marvell.com>
> Signed-off-by: Arie Gershberg <agershberg at marvell.com>
> Signed-off-by: Prabhakar Kushwaha <pkushwaha at marvell.com>
> Signed-off-by: Omkar Kulkarni <okulkarni at marvell.com>
> Signed-off-by: Michal Kalderon <mkalderon at marvell.com>
> Signed-off-by: Ariel Elior <aelior at marvell.com>
> Signed-off-by: Shai Malin <smalin at marvell.com>
> ---
>   drivers/nvme/host/tcp-offload.c | 467 +++++++++++++++++++++++++++++++-
>   1 file changed, 459 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/nvme/host/tcp-offload.c b/drivers/nvme/host/tcp-offload.c
> index aa7cc239abf2..59e1955e02ec 100644
> --- a/drivers/nvme/host/tcp-offload.c
> +++ b/drivers/nvme/host/tcp-offload.c
> @@ -12,6 +12,10 @@
>   
>   static LIST_HEAD(nvme_tcp_ofld_devices);
>   static DECLARE_RWSEM(nvme_tcp_ofld_devices_rwsem);
> +static LIST_HEAD(nvme_tcp_ofld_ctrl_list);
> +static DECLARE_RWSEM(nvme_tcp_ofld_ctrl_rwsem);
> +static struct blk_mq_ops nvme_tcp_ofld_admin_mq_ops;
> +static struct blk_mq_ops nvme_tcp_ofld_mq_ops;
>   
>   static inline struct nvme_tcp_ofld_ctrl *to_tcp_ofld_ctrl(struct nvme_ctrl *nctrl)
>   {
> @@ -128,28 +132,430 @@ nvme_tcp_ofld_lookup_dev(struct nvme_tcp_ofld_ctrl *ctrl)
>   	return dev;
>   }
>   
> +static struct blk_mq_tag_set *
> +nvme_tcp_ofld_alloc_tagset(struct nvme_ctrl *nctrl, bool admin)
> +{
> +	struct nvme_tcp_ofld_ctrl *ctrl = to_tcp_ofld_ctrl(nctrl);
> +	struct blk_mq_tag_set *set;
> +	int rc;
> +
> +	if (admin) {
> +		set = &ctrl->admin_tag_set;
> +		memset(set, 0, sizeof(*set));
> +		set->ops = &nvme_tcp_ofld_admin_mq_ops;
> +		set->queue_depth = NVME_AQ_MQ_TAG_DEPTH;
> +		set->reserved_tags = NVMF_RESERVED_TAGS;
> +		set->numa_node = nctrl->numa_node;
> +		set->flags = BLK_MQ_F_BLOCKING;
> +		set->cmd_size = sizeof(struct nvme_tcp_ofld_req);
> +		set->driver_data = ctrl;
> +		set->nr_hw_queues = 1;
> +		set->timeout = NVME_ADMIN_TIMEOUT;
> +	} else {
> +		set = &ctrl->tag_set;
> +		memset(set, 0, sizeof(*set));
> +		set->ops = &nvme_tcp_ofld_mq_ops;
> +		set->queue_depth = nctrl->sqsize + 1;
> +		set->reserved_tags = NVMF_RESERVED_TAGS;
> +		set->numa_node = nctrl->numa_node;
> +		set->flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING;
> +		set->cmd_size = sizeof(struct nvme_tcp_ofld_req);
> +		set->driver_data = ctrl;
> +		set->nr_hw_queues = nctrl->queue_count - 1;
> +		set->timeout = NVME_IO_TIMEOUT;
> +		set->nr_maps = nctrl->opts->nr_poll_queues ? HCTX_MAX_TYPES : 2;
> +	}
> +
> +	rc = blk_mq_alloc_tag_set(set);
> +	if (rc)
> +		return ERR_PTR(rc);
> +
> +	return set;
> +}
> +
> +static int nvme_tcp_ofld_configure_admin_queue(struct nvme_ctrl *nctrl,
> +					       bool new)
> +{
> +	int rc;
> +
> +	/* Placeholder - alloc_admin_queue */
> +	if (new) {
> +		nctrl->admin_tagset =
> +				nvme_tcp_ofld_alloc_tagset(nctrl, true);
> +		if (IS_ERR(nctrl->admin_tagset)) {
> +			rc = PTR_ERR(nctrl->admin_tagset);
> +			nctrl->admin_tagset = NULL;
> +			goto out_free_queue;
> +		}
> +
> +		nctrl->fabrics_q = blk_mq_init_queue(nctrl->admin_tagset);
> +		if (IS_ERR(nctrl->fabrics_q)) {
> +			rc = PTR_ERR(nctrl->fabrics_q);
> +			nctrl->fabrics_q = NULL;
> +			goto out_free_tagset;
> +		}
> +
> +		nctrl->admin_q = blk_mq_init_queue(nctrl->admin_tagset);
> +		if (IS_ERR(nctrl->admin_q)) {
> +			rc = PTR_ERR(nctrl->admin_q);
> +			nctrl->admin_q = NULL;
> +			goto out_cleanup_fabrics_q;
> +		}
> +	}
> +
> +	/* Placeholder - nvme_tcp_ofld_start_queue */
> +
> +	rc = nvme_enable_ctrl(nctrl);
> +	if (rc)
> +		goto out_stop_queue;
> +
> +	blk_mq_unquiesce_queue(nctrl->admin_q);
> +
> +	rc = nvme_init_identify(nctrl);
> +	if (rc)
> +		goto out_quiesce_queue;
> +
> +	return 0;
> +
> +out_quiesce_queue:
> +	blk_mq_quiesce_queue(nctrl->admin_q);
> +	blk_sync_queue(nctrl->admin_q);
> +
> +out_stop_queue:
> +	/* Placeholder - stop offload queue */
> +	nvme_cancel_admin_tagset(nctrl);
> +
> +out_cleanup_fabrics_q:
> +	if (new)
> +		blk_cleanup_queue(nctrl->fabrics_q);
> +out_free_tagset:
> +	if (new)
> +		blk_mq_free_tag_set(nctrl->admin_tagset);
> +out_free_queue:
> +	/* Placeholder - free admin queue */
> +
> +	return rc;
> +}
> +
> +static int
> +nvme_tcp_ofld_configure_io_queues(struct nvme_ctrl *nctrl, bool new)
> +{
> +	int rc;
> +
> +	/* Placeholder - alloc_io_queues */
> +
> +	if (new) {
> +		nctrl->tagset = nvme_tcp_ofld_alloc_tagset(nctrl, false);
> +		if (IS_ERR(nctrl->tagset)) {
> +			rc = PTR_ERR(nctrl->tagset);
> +			nctrl->tagset = NULL;
> +			goto out_free_io_queues;
> +		}
> +
> +		nctrl->connect_q = blk_mq_init_queue(nctrl->tagset);
> +		if (IS_ERR(nctrl->connect_q)) {
> +			rc = PTR_ERR(nctrl->connect_q);
> +			nctrl->connect_q = NULL;
> +			goto out_free_tag_set;
> +		}
> +	}
> +
> +	/* Placeholder - start_io_queues */
> +
> +	if (!new) {
> +		nvme_start_queues(nctrl);
> +		if (!nvme_wait_freeze_timeout(nctrl, NVME_IO_TIMEOUT)) {
> +			/*
> +			 * If we timed out waiting for freeze we are likely to
> +			 * be stuck.  Fail the controller initialization just
> +			 * to be safe.
> +			 */
> +			rc = -ENODEV;
> +			goto out_wait_freeze_timed_out;
> +		}
> +		blk_mq_update_nr_hw_queues(nctrl->tagset, nctrl->queue_count - 1);
> +		nvme_unfreeze(nctrl);
> +	}
> +
> +	return 0;
> +
> +out_wait_freeze_timed_out:
> +	nvme_stop_queues(nctrl);
> +	nvme_sync_io_queues(nctrl);
> +
> +	/* Placeholder - Stop IO queues */
> +
> +	if (new)
> +		blk_cleanup_queue(nctrl->connect_q);
> +out_free_tag_set:
> +	if (new)
> +		blk_mq_free_tag_set(nctrl->tagset);
> +out_free_io_queues:
> +	/* Placeholder - free_io_queues */
> +
> +	return rc;
> +}
> +
>   static int nvme_tcp_ofld_setup_ctrl(struct nvme_ctrl *nctrl, bool new)
>   {
> -	/* Placeholder - validates inputs and creates admin and IO queues */
> +	struct nvmf_ctrl_options *opts = nctrl->opts;
> +	int rc;
> +
> +	rc = nvme_tcp_ofld_configure_admin_queue(nctrl, new);
> +	if (rc)
> +		return rc;
> +
> +	if (nctrl->icdoff) {
> +		dev_err(nctrl->device, "icdoff is not supported!\n");
> +		rc = -EINVAL;
> +		goto destroy_admin;
> +	}
> +
> +	if (opts->queue_size > nctrl->sqsize + 1)
> +		dev_warn(nctrl->device,
> +			 "queue_size %zu > ctrl sqsize %u, clamping down\n",
> +			 opts->queue_size, nctrl->sqsize + 1);
> +
> +	if (nctrl->sqsize + 1 > nctrl->maxcmd) {
> +		dev_warn(nctrl->device,
> +			 "sqsize %u > ctrl maxcmd %u, clamping down\n",
> +			 nctrl->sqsize + 1, nctrl->maxcmd);
> +		nctrl->sqsize = nctrl->maxcmd - 1;
> +	}
> +
> +	if (nctrl->queue_count > 1) {
> +		rc = nvme_tcp_ofld_configure_io_queues(nctrl, new);
> +		if (rc)
> +			goto destroy_admin;
> +	}
> +
> +	if (!nvme_change_ctrl_state(nctrl, NVME_CTRL_LIVE)) {
> +		/*
> +		 * state change failure is ok if we started ctrl delete,
> +		 * unless we're during creation of a new controller to
> +		 * avoid races with teardown flow.
> +		 */
> +		WARN_ON_ONCE(nctrl->state != NVME_CTRL_DELETING &&
> +			     nctrl->state != NVME_CTRL_DELETING_NOIO);
> +		WARN_ON_ONCE(new);
> +		rc = -EINVAL;
> +		goto destroy_io;
> +	}
> +
> +	nvme_start_ctrl(nctrl);
> +
> +	return 0;
> +
> +destroy_io:
> +	/* Placeholder - stop and destroy io queues*/
> +destroy_admin:
> +	/* Placeholder - stop and destroy admin queue*/
> +
> +	return rc;
> +}
> +
> +static int
> +nvme_tcp_ofld_check_dev_opts(struct nvmf_ctrl_options *opts,
> +			     struct nvme_tcp_ofld_ops *ofld_ops)
> +{
> +	unsigned int nvme_tcp_ofld_opt_mask = NVMF_ALLOWED_OPTS |
> +			ofld_ops->allowed_opts | ofld_ops->required_opts;
> +	if (opts->mask & ~nvme_tcp_ofld_opt_mask) {
> +		pr_warn("One or more of the nvmf options isn't supported by %s.\n",
> +			ofld_ops->name);
> +
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +

I'd rather specify the options directly; that's how all the other 
transports do it.

> +static void nvme_tcp_ofld_free_ctrl(struct nvme_ctrl *nctrl)
> +{
> +	struct nvme_tcp_ofld_ctrl *ctrl = to_tcp_ofld_ctrl(nctrl);
> +	struct nvme_tcp_ofld_dev *dev = ctrl->dev;
> +
> +	if (list_empty(&ctrl->list))
> +		goto free_ctrl;
> +
> +	down_write(&nvme_tcp_ofld_ctrl_rwsem);
> +	ctrl->dev->ops->release_ctrl(ctrl);
> +	list_del(&ctrl->list);
> +	up_write(&nvme_tcp_ofld_ctrl_rwsem);
> +
> +	nvmf_free_options(nctrl->opts);
> +free_ctrl:
> +	module_put(dev->ops->module);
> +	kfree(ctrl->queues);
> +	kfree(ctrl);
> +}
> +
> +static void nvme_tcp_ofld_submit_async_event(struct nvme_ctrl *arg)
> +{
> +	/* Placeholder - submit_async_event */
> +}
> +
> +static void
> +nvme_tcp_ofld_teardown_admin_queue(struct nvme_ctrl *ctrl, bool remove)
> +{
> +	/* Placeholder - teardown_admin_queue */
> +}
> +
> +static void
> +nvme_tcp_ofld_teardown_io_queues(struct nvme_ctrl *nctrl, bool remove)
> +{
> +	/* Placeholder - teardown_io_queues */
> +}
> +
> +static void
> +nvme_tcp_ofld_teardown_ctrl(struct nvme_ctrl *nctrl, bool shutdown)
> +{
> +	/* Placeholder - err_work and connect_work */
> +	nvme_tcp_ofld_teardown_io_queues(nctrl, shutdown);
> +	blk_mq_quiesce_queue(nctrl->admin_q);
> +	if (shutdown)
> +		nvme_shutdown_ctrl(nctrl);
> +	else
> +		nvme_disable_ctrl(nctrl);
> +	nvme_tcp_ofld_teardown_admin_queue(nctrl, shutdown);
> +}
> +
> +static void nvme_tcp_ofld_delete_ctrl(struct nvme_ctrl *nctrl)
> +{
> +	nvme_tcp_ofld_teardown_ctrl(nctrl, true);
> +}
> +
> +static int
> +nvme_tcp_ofld_init_request(struct blk_mq_tag_set *set,
> +			   struct request *rq,
> +			   unsigned int hctx_idx,
> +			   unsigned int numa_node)
> +{
> +	struct nvme_tcp_ofld_req *req = blk_mq_rq_to_pdu(rq);
> +	struct nvme_tcp_ofld_ctrl *ctrl = set->driver_data;
> +
> +	/* Placeholder - init request */
> +
> +	req->done = nvme_tcp_ofld_req_done;
> +	ctrl->dev->ops->init_req(req);
>   
>   	return 0;
>   }
>   
> +static blk_status_t
> +nvme_tcp_ofld_queue_rq(struct blk_mq_hw_ctx *hctx,
> +		       const struct blk_mq_queue_data *bd)
> +{
> +	/* Call nvme_setup_cmd(...) */
> +
> +	/* Call ops->send_req(...) */
> +
> +	return BLK_STS_OK;
> +}
> +
> +static struct blk_mq_ops nvme_tcp_ofld_mq_ops = {
> +	.queue_rq	= nvme_tcp_ofld_queue_rq,
> +	.init_request	= nvme_tcp_ofld_init_request,
> +	/*
> +	 * All additional ops will be also implemented and registered similar to
> +	 * tcp.c
> +	 */
> +};
> +
> +static struct blk_mq_ops nvme_tcp_ofld_admin_mq_ops = {
> +	.queue_rq	= nvme_tcp_ofld_queue_rq,
> +	.init_request	= nvme_tcp_ofld_init_request,
> +	/*
> +	 * All additional ops will be also implemented and registered similar to
> +	 * tcp.c
> +	 */
> +};
> +
> +static const struct nvme_ctrl_ops nvme_tcp_ofld_ctrl_ops = {
> +	.name			= "tcp_offload",
> +	.module			= THIS_MODULE,
> +	.flags			= NVME_F_FABRICS,
> +	.reg_read32		= nvmf_reg_read32,
> +	.reg_read64		= nvmf_reg_read64,
> +	.reg_write32		= nvmf_reg_write32,
> +	.free_ctrl		= nvme_tcp_ofld_free_ctrl,
> +	.submit_async_event	= nvme_tcp_ofld_submit_async_event,
> +	.delete_ctrl		= nvme_tcp_ofld_delete_ctrl,
> +	.get_address		= nvmf_get_address,
> +};
> +
> +static bool
> +nvme_tcp_ofld_existing_controller(struct nvmf_ctrl_options *opts)
> +{
> +	struct nvme_tcp_ofld_ctrl *ctrl;
> +	bool found = false;
> +
> +	down_read(&nvme_tcp_ofld_ctrl_rwsem);
> +	list_for_each_entry(ctrl, &nvme_tcp_ofld_ctrl_list, list) {
> +		found = nvmf_ip_options_match(&ctrl->nctrl, opts);
> +		if (found)
> +			break;
> +	}
> +	up_read(&nvme_tcp_ofld_ctrl_rwsem);
> +
> +	return found;
> +}
> +
>   static struct nvme_ctrl *
>   nvme_tcp_ofld_create_ctrl(struct device *ndev, struct nvmf_ctrl_options *opts)
>   {
> +	struct nvme_tcp_ofld_queue *queue;
>   	struct nvme_tcp_ofld_ctrl *ctrl;
>   	struct nvme_tcp_ofld_dev *dev;
>   	struct nvme_ctrl *nctrl;
> -	int rc = 0;
> +	int i, rc = 0;
>   
>   	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
>   	if (!ctrl)
>   		return ERR_PTR(-ENOMEM);
>   
> +	INIT_LIST_HEAD(&ctrl->list);
>   	nctrl = &ctrl->nctrl;
> +	nctrl->opts = opts;
> +	nctrl->queue_count = opts->nr_io_queues + opts->nr_write_queues +
> +			     opts->nr_poll_queues + 1;
> +	nctrl->sqsize = opts->queue_size - 1;
> +	nctrl->kato = opts->kato;
> +	if (!(opts->mask & NVMF_OPT_TRSVCID)) {
> +		opts->trsvcid =
> +			kstrdup(__stringify(NVME_TCP_DISC_PORT), GFP_KERNEL);
> +		if (!opts->trsvcid) {
> +			rc = -ENOMEM;
> +			goto out_free_ctrl;
> +		}
> +		opts->mask |= NVMF_OPT_TRSVCID;
> +	}
>   
> -	/* Init nvme_tcp_ofld_ctrl and nvme_ctrl params based on received opts */
> +	rc = inet_pton_with_scope(&init_net, AF_UNSPEC, opts->traddr,
> +				  opts->trsvcid,
> +				  &ctrl->conn_params.remote_ip_addr);
> +	if (rc) {
> +		pr_err("malformed address passed: %s:%s\n",
> +		       opts->traddr, opts->trsvcid);
> +		goto out_free_ctrl;
> +	}
> +
> +	if (opts->mask & NVMF_OPT_HOST_TRADDR) {
> +		rc = inet_pton_with_scope(&init_net, AF_UNSPEC,
> +					  opts->host_traddr, NULL,
> +					  &ctrl->conn_params.local_ip_addr);
> +		if (rc) {
> +			pr_err("malformed src address passed: %s\n",
> +			       opts->host_traddr);
> +			goto out_free_ctrl;
> +		}
> +	}
> +
> +	if (!opts->duplicate_connect &&
> +	    nvme_tcp_ofld_existing_controller(opts)) {
> +		rc = -EALREADY;
> +		goto out_free_ctrl;
> +	}
>   
>   	/* Find device that can reach the dest addr */
>   	dev = nvme_tcp_ofld_lookup_dev(ctrl);
As mentioned in my previous comment: This is not necessarily unique.
There is no guarantee that a specific host ip/target ip combination will 
devolve onto a single interface; in fact, given that this is an offload 
card which might handle only specific protocols I fully expect to have 
several interfaces through which the target ip address can be reached.

One could implement some sort of prioritisation such that offload 
engines should be preferred, but in the end it's a policy decision and 
not something we should impose from the driver side.

I'd rather be able to specify an interface directly, and tie specific
host ip/target ip connections (ie host_traddr/traddr combinations) to 
that interface. That way we don't impose restrictions on the admin,
and remove ambiguity when creating the controller from userspace.

> @@ -160,6 +566,10 @@ nvme_tcp_ofld_create_ctrl(struct device *ndev, struct nvmf_ctrl_options *opts)
>   		goto out_free_ctrl;
>   	}
>   
> +	rc = nvme_tcp_ofld_check_dev_opts(opts, dev->ops);
> +	if (rc)
> +		goto out_module_put;
> +
>   	ctrl->dev = dev;
>   
>   	if (ctrl->dev->ops->max_hw_sectors)
> @@ -167,22 +577,55 @@ nvme_tcp_ofld_create_ctrl(struct device *ndev, struct nvmf_ctrl_options *opts)
>   	if (ctrl->dev->ops->max_segments)
>   		nctrl->max_segments = ctrl->dev->ops->max_segments;
>   
> -	/* Init queues */
> +	ctrl->queues = kcalloc(nctrl->queue_count,
> +			       sizeof(struct nvme_tcp_ofld_queue),
> +			       GFP_KERNEL);
> +	if (!ctrl->queues) {
> +		rc = -ENOMEM;
> +		goto out_module_put;
> +	}
>   
> -	/* Call nvme_init_ctrl */
> +	for (i = 0; i < nctrl->queue_count; ++i) {
> +		queue = &ctrl->queues[i];
> +		queue->ctrl = ctrl;
> +		queue->dev = dev;
> +		queue->report_err = nvme_tcp_ofld_report_queue_err;
> +	}
> +

What does this 'report_err' callback do?
Maybe it's easier to understand when it's introduced alongside with the 
code handling it.

> +	rc = nvme_init_ctrl(nctrl, ndev, &nvme_tcp_ofld_ctrl_ops, 0);
> +	if (rc)
> +		goto out_free_queues;
> +
> +	if (!nvme_change_ctrl_state(nctrl, NVME_CTRL_CONNECTING)) {
> +		WARN_ON_ONCE(1);
> +		rc = -EINTR;
> +		goto out_uninit_ctrl;
> +	}
>   
>   	rc = ctrl->dev->ops->setup_ctrl(ctrl, true);
>   	if (rc)
> -		goto out_module_put;
> +		goto out_uninit_ctrl;
>   
>   	rc = nvme_tcp_ofld_setup_ctrl(nctrl, true);
>   	if (rc)
> -		goto out_uninit_ctrl;
> +		goto out_release_ctrl;
> +
> +	dev_info(nctrl->device, "new ctrl: NQN \"%s\", addr %pISp\n",
> +		 opts->subsysnqn, &ctrl->conn_params.remote_ip_addr);
> +
> +	down_write(&nvme_tcp_ofld_ctrl_rwsem);
> +	list_add_tail(&ctrl->list, &nvme_tcp_ofld_ctrl_list);
> +	up_write(&nvme_tcp_ofld_ctrl_rwsem);
>   
>   	return nctrl;
>   
> -out_uninit_ctrl:
> +out_release_ctrl:
>   	ctrl->dev->ops->release_ctrl(ctrl);
> +out_uninit_ctrl:
> +	nvme_uninit_ctrl(nctrl);
> +	nvme_put_ctrl(nctrl);
> +out_free_queues:
> +	kfree(ctrl->queues);
>   out_module_put:
>   	module_put(dev->ops->module);
>   out_free_ctrl:
> @@ -212,7 +655,15 @@ static int __init nvme_tcp_ofld_init_module(void)
>   
>   static void __exit nvme_tcp_ofld_cleanup_module(void)
>   {
> +	struct nvme_tcp_ofld_ctrl *ctrl;
> +
>   	nvmf_unregister_transport(&nvme_tcp_ofld_transport);
> +
> +	down_write(&nvme_tcp_ofld_ctrl_rwsem);
> +	list_for_each_entry(ctrl, &nvme_tcp_ofld_ctrl_list, list)
> +		nvme_delete_ctrl(&ctrl->nctrl);
> +	up_write(&nvme_tcp_ofld_ctrl_rwsem);
> +	flush_workqueue(nvme_delete_wq);
>   }
>   
>   module_init(nvme_tcp_ofld_init_module);
> 
Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare at suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer



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