text: // SPDX-License-Identifier: GPL-2.0
  /*
   * NVMe over Fabrics common host code.
   * Copyright (c) 2015-2016 HGST, a Western Digital Company.
   */
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  #include <linux/init.h>
  #include <linux/miscdevice.h>
  #include <linux/module.h>
  #include <linux/mutex.h>
  #include <linux/parser.h>
  #include <linux/seq_file.h>
  #include "nvme.h"
  #include "fabrics.h"
  
  static LIST_HEAD(nvmf_transports);
  static DECLARE_RWSEM(nvmf_transports_rwsem);
  
  static LIST_HEAD(nvmf_hosts);
  static DEFINE_MUTEX(nvmf_hosts_mutex);
  
  static struct nvmf_host *nvmf_default_host;
  
  static struct nvmf_host *__nvmf_host_find(const char *hostnqn)
  {
  	struct nvmf_host *host;
  
  	list_for_each_entry(host, &nvmf_hosts, list) {
  		if (!strcmp(host->nqn, hostnqn))
  			return host;
  	}
  
  	return NULL;
  }
  
  static struct nvmf_host *nvmf_host_add(const char *hostnqn)
  {
  	struct nvmf_host *host;
  
  	mutex_lock(&nvmf_hosts_mutex);
  	host = __nvmf_host_find(hostnqn);
  	if (host) {
  		kref_get(&host->ref);
  		goto out_unlock;
  	}
  
  	host = kmalloc(sizeof(*host), GFP_KERNEL);
  	if (!host)
  		goto out_unlock;
  
  	kref_init(&host->ref);
  	strlcpy(host->nqn, hostnqn, NVMF_NQN_SIZE);
  
  	list_add_tail(&host->list, &nvmf_hosts);
  out_unlock:
  	mutex_unlock(&nvmf_hosts_mutex);
  	return host;
  }
  
  static struct nvmf_host *nvmf_host_default(void)
  {
  	struct nvmf_host *host;
  
  	host = kmalloc(sizeof(*host), GFP_KERNEL);
  	if (!host)
  		return NULL;
  
  	kref_init(&host->ref);
  	uuid_gen(&host->id);
  	snprintf(host->nqn, NVMF_NQN_SIZE,
  		"nqn.2014-08.org.nvmexpress:uuid:%pUb", &host->id);
  
  	mutex_lock(&nvmf_hosts_mutex);
  	list_add_tail(&host->list, &nvmf_hosts);
  	mutex_unlock(&nvmf_hosts_mutex);
  
  	return host;
  }
  
  static void nvmf_host_destroy(struct kref *ref)
  {
  	struct nvmf_host *host = container_of(ref, struct nvmf_host, ref);
  
  	mutex_lock(&nvmf_hosts_mutex);
  	list_del(&host->list);
  	mutex_unlock(&nvmf_hosts_mutex);
  
  	kfree(host);
  }
  
  static void nvmf_host_put(struct nvmf_host *host)
  {
  	if (host)
  		kref_put(&host->ref, nvmf_host_destroy);
  }
  
  /**
   * nvmf_get_address() -  Get address/port
   * @ctrl:	Host NVMe controller instance which we got the address
   * @buf:	OUTPUT parameter that will contain the address/port
   * @size:	buffer size
   */
  int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
  {
  	int len = 0;
  
  	if (ctrl->opts->mask & NVMF_OPT_TRADDR)
  		len += scnprintf(buf, size, "traddr=%s", ctrl->opts->traddr);
  	if (ctrl->opts->mask & NVMF_OPT_TRSVCID)
  		len += scnprintf(buf + len, size - len, "%strsvcid=%s",
  				(len) ? "," : "", ctrl->opts->trsvcid);
  	if (ctrl->opts->mask & NVMF_OPT_HOST_TRADDR)
  		len += scnprintf(buf + len, size - len, "%shost_traddr=%s",
  				(len) ? "," : "", ctrl->opts->host_traddr);
  	if (ctrl->opts->mask & NVMF_OPT_HOST_IFACE)
  		len += scnprintf(buf + len, size - len, "%shost_iface=%s",
  				(len) ? "," : "", ctrl->opts->host_iface);
  	len += scnprintf(buf + len, size - len, "\n");
  
  	return len;
  }
  EXPORT_SYMBOL_GPL(nvmf_get_address);
  
  /**
   * nvmf_reg_read32() -  NVMe Fabrics "Property Get" API function.
   * @ctrl:	Host NVMe controller instance maintaining the admin
   *		queue used to submit the property read command to
   *		the allocated NVMe controller resource on the target system.
   * @off:	Starting offset value of the targeted property
   *		register (see the fabrics section of the NVMe standard).
   * @val:	OUTPUT parameter that will contain the value of
   *		the property after a successful read.
   *
   * Used by the host system to retrieve a 32-bit capsule property value
   * from an NVMe controller on the target system.
   *
   * ("Capsule property" is an "PCIe register concept" applied to the
   * NVMe fabrics space.)
   *
   * Return:
   *	0: successful read
   *	> 0: NVMe error status code
   *	< 0: Linux errno error code
   */
  int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
  {
  	struct nvme_command cmd;
  	union nvme_result res;
  	int ret;
  
  	memset(&cmd, 0, sizeof(cmd));
  	cmd.prop_get.opcode = nvme_fabrics_command;
  	cmd.prop_get.fctype = nvme_fabrics_type_property_get;
  	cmd.prop_get.offset = cpu_to_le32(off);
  
  	ret = __nvme_submit_sync_cmd(ctrl->fabrics_q, &cmd, &res, NULL, 0, 0,
  			NVME_QID_ANY, 0, 0);
  
  	if (ret >= 0)
  		*val = le64_to_cpu(res.u64);
  	if (unlikely(ret != 0))
  		dev_err(ctrl->device,
  			"Property Get error: %d, offset %#x\n",
  			ret > 0 ? ret & ~NVME_SC_DNR : ret, off);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(nvmf_reg_read32);
  
  /**
   * nvmf_reg_read64() -  NVMe Fabrics "Property Get" API function.
   * @ctrl:	Host NVMe controller instance maintaining the admin
   *		queue used to submit the property read command to
   *		the allocated controller resource on the target system.
   * @off:	Starting offset value of the targeted property
   *		register (see the fabrics section of the NVMe standard).
   * @val:	OUTPUT parameter that will contain the value of
   *		the property after a successful read.
   *
   * Used by the host system to retrieve a 64-bit capsule property value
   * from an NVMe controller on the target system.
   *
   * ("Capsule property" is an "PCIe register concept" applied to the
   * NVMe fabrics space.)
   *
   * Return:
   *	0: successful read
   *	> 0: NVMe error status code
   *	< 0: Linux errno error code
   */
  int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
  {
  	struct nvme_command cmd = { };
  	union nvme_result res;
  	int ret;
  
  	cmd.prop_get.opcode = nvme_fabrics_command;
  	cmd.prop_get.fctype = nvme_fabrics_type_property_get;
  	cmd.prop_get.attrib = 1;
  	cmd.prop_get.offset = cpu_to_le32(off);
  
  	ret = __nvme_submit_sync_cmd(ctrl->fabrics_q, &cmd, &res, NULL, 0, 0,
  			NVME_QID_ANY, 0, 0);
  
  	if (ret >= 0)
  		*val = le64_to_cpu(res.u64);
  	if (unlikely(ret != 0))
  		dev_err(ctrl->device,
  			"Property Get error: %d, offset %#x\n",
  			ret > 0 ? ret & ~NVME_SC_DNR : ret, off);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(nvmf_reg_read64);
  
  /**
   * nvmf_reg_write32() -  NVMe Fabrics "Property Write" API function.
   * @ctrl:	Host NVMe controller instance maintaining the admin
   *		queue used to submit the property read command to
   *		the allocated NVMe controller resource on the target system.
   * @off:	Starting offset value of the targeted property
   *		register (see the fabrics section of the NVMe standard).
   * @val:	Input parameter that contains the value to be
   *		written to the property.
   *
   * Used by the NVMe host system to write a 32-bit capsule property value
   * to an NVMe controller on the target system.
   *
   * ("Capsule property" is an "PCIe register concept" applied to the
   * NVMe fabrics space.)
   *
   * Return:
   *	0: successful write
   *	> 0: NVMe error status code
   *	< 0: Linux errno error code
   */
  int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val)
  {
  	struct nvme_command cmd = { };
  	int ret;
  
  	cmd.prop_set.opcode = nvme_fabrics_command;
  	cmd.prop_set.fctype = nvme_fabrics_type_property_set;
  	cmd.prop_set.attrib = 0;
  	cmd.prop_set.offset = cpu_to_le32(off);
  	cmd.prop_set.value = cpu_to_le64(val);
  
  	ret = __nvme_submit_sync_cmd(ctrl->fabrics_q, &cmd, NULL, NULL, 0, 0,
  			NVME_QID_ANY, 0, 0);
  	if (unlikely(ret))
  		dev_err(ctrl->device,
  			"Property Set error: %d, offset %#x\n",
  			ret > 0 ? ret & ~NVME_SC_DNR : ret, off);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(nvmf_reg_write32);
  
  /**
   * nvmf_log_connect_error() - Error-parsing-diagnostic print out function for
   * 				connect() errors.
   * @ctrl:	The specific /dev/nvmeX device that had the error.
   * @errval:	Error code to be decoded in a more human-friendly
   * 		printout.
   * @offset:	For use with the NVMe error code
   * 		NVME_SC_CONNECT_INVALID_PARAM.
   * @cmd:	This is the SQE portion of a submission capsule.
   * @data:	This is the "Data" portion of a submission capsule.
   */
  static void nvmf_log_connect_error(struct nvme_ctrl *ctrl,
  		int errval, int offset, struct nvme_command *cmd,
  		struct nvmf_connect_data *data)
  {
  	int err_sctype = errval & ~NVME_SC_DNR;
  
  	switch (err_sctype) {
  	case (NVME_SC_CONNECT_INVALID_PARAM):
  		if (offset >> 16) {
  			char *inv_data = "Connect Invalid Data Parameter";
  
  			switch (offset & 0xffff) {
  			case (offsetof(struct nvmf_connect_data, cntlid)):
  				dev_err(ctrl->device,
  					"%s, cntlid: %d\n",
  					inv_data, data->cntlid);
  				break;
  			case (offsetof(struct nvmf_connect_data, hostnqn)):
  				dev_err(ctrl->device,
  					"%s, hostnqn \"%s\"\n",
  					inv_data, data->hostnqn);
  				break;
  			case (offsetof(struct nvmf_connect_data, subsysnqn)):
  				dev_err(ctrl->device,
  					"%s, subsysnqn \"%s\"\n",
  					inv_data, data->subsysnqn);
  				break;
  			default:
  				dev_err(ctrl->device,
  					"%s, starting byte offset: %d\n",
  				       inv_data, offset & 0xffff);
  				break;
  			}
  		} else {
  			char *inv_sqe = "Connect Invalid SQE Parameter";
  
  			switch (offset) {
  			case (offsetof(struct nvmf_connect_command, qid)):
  				dev_err(ctrl->device,
  				       "%s, qid %d\n",
  					inv_sqe, cmd->connect.qid);
  				break;
  			default:
  				dev_err(ctrl->device,
  					"%s, starting byte offset: %d\n",
  					inv_sqe, offset);
  			}
  		}
  		break;
  	case NVME_SC_CONNECT_INVALID_HOST:
  		dev_err(ctrl->device,
  			"Connect for subsystem %s is not allowed, hostnqn: %s\n",
  			data->subsysnqn, data->hostnqn);
  		break;
  	case NVME_SC_CONNECT_CTRL_BUSY:
  		dev_err(ctrl->device,
  			"Connect command failed: controller is busy or not available\n");
  		break;
  	case NVME_SC_CONNECT_FORMAT:
  		dev_err(ctrl->device,
  			"Connect incompatible format: %d",
  			cmd->connect.recfmt);
  		break;
  	case NVME_SC_HOST_PATH_ERROR:
  		dev_err(ctrl->device,
  			"Connect command failed: host path error\n");
  		break;
  	default:
  		dev_err(ctrl->device,
  			"Connect command failed, error wo/DNR bit: %d\n",
  			err_sctype);
  		break;
  	}
  }
  
  /**
   * nvmf_connect_admin_queue() - NVMe Fabrics Admin Queue "Connect"
   *				API function.
   * @ctrl:	Host nvme controller instance used to request
   *              a new NVMe controller allocation on the target
   *              system and  establish an NVMe Admin connection to
   *              that controller.
   *
   * This function enables an NVMe host device to request a new allocation of
   * an NVMe controller resource on a target system as well establish a
   * fabrics-protocol connection of the NVMe Admin queue between the
   * host system device and the allocated NVMe controller on the
   * target system via a NVMe Fabrics "Connect" command.
   *
   * Return:
   *	0: success
   *	> 0: NVMe error status code
   *	< 0: Linux errno error code
   *
   */
  int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl)
  {
  	struct nvme_command cmd = { };
  	union nvme_result res;
  	struct nvmf_connect_data *data;
  	int ret;
  
  	cmd.connect.opcode = nvme_fabrics_command;
  	cmd.connect.fctype = nvme_fabrics_type_connect;
  	cmd.connect.qid = 0;
  	cmd.connect.sqsize = cpu_to_le16(NVME_AQ_DEPTH - 1);
  
  	/*
  	 * Set keep-alive timeout in seconds granularity (ms * 1000)
  	 */
  	cmd.connect.kato = cpu_to_le32(ctrl->kato * 1000);
  
  	if (ctrl->opts->disable_sqflow)
  		cmd.connect.cattr |= NVME_CONNECT_DISABLE_SQFLOW;
  
  	data = kzalloc(sizeof(*data), GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;
  
  	uuid_copy(&data->hostid, &ctrl->opts->host->id);
  	data->cntlid = cpu_to_le16(0xffff);
  	strncpy(data->subsysnqn, ctrl->opts->subsysnqn, NVMF_NQN_SIZE);
  	strncpy(data->hostnqn, ctrl->opts->host->nqn, NVMF_NQN_SIZE);
  
  	ret = __nvme_submit_sync_cmd(ctrl->fabrics_q, &cmd, &res,
  			data, sizeof(*data), 0, NVME_QID_ANY, 1,
  			BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT);
  	if (ret) {
  		nvmf_log_connect_error(ctrl, ret, le32_to_cpu(res.u32),
  				       &cmd, data);
  		goto out_free_data;
  	}
  
  	ctrl->cntlid = le16_to_cpu(res.u16);
  
  out_free_data:
  	kfree(data);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(nvmf_connect_admin_queue);
  
  /**
   * nvmf_connect_io_queue() - NVMe Fabrics I/O Queue "Connect"
   *			     API function.
   * @ctrl:	Host nvme controller instance used to establish an
   *		NVMe I/O queue connection to the already allocated NVMe
   *		controller on the target system.
   * @qid:	NVMe I/O queue number for the new I/O connection between
   *		host and target (note qid == 0 is illegal as this is
   *		the Admin queue, per NVMe standard).
   *
   * This function issues a fabrics-protocol connection
   * of a NVMe I/O queue (via NVMe Fabrics "Connect" command)
   * between the host system device and the allocated NVMe controller
   * on the target system.
   *
   * Return:
   *	0: success
   *	> 0: NVMe error status code
   *	< 0: Linux errno error code
   */
  int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid)
  {
  	struct nvme_command cmd = { };
  	struct nvmf_connect_data *data;
  	union nvme_result res;
  	int ret;
  
  	cmd.connect.opcode = nvme_fabrics_command;
  	cmd.connect.fctype = nvme_fabrics_type_connect;
  	cmd.connect.qid = cpu_to_le16(qid);
  	cmd.connect.sqsize = cpu_to_le16(ctrl->sqsize);
  
  	if (ctrl->opts->disable_sqflow)
  		cmd.connect.cattr |= NVME_CONNECT_DISABLE_SQFLOW;
  
  	data = kzalloc(sizeof(*data), GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;
  
  	uuid_copy(&data->hostid, &ctrl->opts->host->id);
  	data->cntlid = cpu_to_le16(ctrl->cntlid);
  	strncpy(data->subsysnqn, ctrl->opts->subsysnqn, NVMF_NQN_SIZE);
  	strncpy(data->hostnqn, ctrl->opts->host->nqn, NVMF_NQN_SIZE);
  
  	ret = __nvme_submit_sync_cmd(ctrl->connect_q, &cmd, &res,
  			data, sizeof(*data), 0, qid, 1,
  			BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT);
  	if (ret) {
  		nvmf_log_connect_error(ctrl, ret, le32_to_cpu(res.u32),
  				       &cmd, data);
  	}
  	kfree(data);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(nvmf_connect_io_queue);
  
  bool nvmf_should_reconnect(struct nvme_ctrl *ctrl)
  {
  	if (ctrl->opts->max_reconnects == -1 ||
  	    ctrl->nr_reconnects < ctrl->opts->max_reconnects)
  		return true;
  
  	return false;
  }
  EXPORT_SYMBOL_GPL(nvmf_should_reconnect);
  
  /**
   * nvmf_register_transport() - NVMe Fabrics Library registration function.
   * @ops:	Transport ops instance to be registered to the
   *		common fabrics library.
   *
   * API function that registers the type of specific transport fabric
   * being implemented to the common NVMe fabrics library. Part of
   * the overall init sequence of starting up a fabrics driver.
   */
  int nvmf_register_transport(struct nvmf_transport_ops *ops)
  {
  	if (!ops->create_ctrl)
  		return -EINVAL;
  
  	down_write(&nvmf_transports_rwsem);
  	list_add_tail(&ops->entry, &nvmf_transports);
  	up_write(&nvmf_transports_rwsem);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(nvmf_register_transport);
  
  /**
   * nvmf_unregister_transport() - NVMe Fabrics Library unregistration function.
   * @ops:	Transport ops instance to be unregistered from the
   *		common fabrics library.
   *
   * Fabrics API function that unregisters the type of specific transport
   * fabric being implemented from the common NVMe fabrics library.
   * Part of the overall exit sequence of unloading the implemented driver.
   */
  void nvmf_unregister_transport(struct nvmf_transport_ops *ops)
  {
  	down_write(&nvmf_transports_rwsem);
  	list_del(&ops->entry);
  	up_write(&nvmf_transports_rwsem);
  }
  EXPORT_SYMBOL_GPL(nvmf_unregister_transport);
  
  static struct nvmf_transport_ops *nvmf_lookup_transport(
  		struct nvmf_ctrl_options *opts)
  {
  	struct nvmf_transport_ops *ops;
  
  	lockdep_assert_held(&nvmf_transports_rwsem);
  
  	list_for_each_entry(ops, &nvmf_transports, entry) {
  		if (strcmp(ops->name, opts->transport) == 0)
  			return ops;
  	}
  
  	return NULL;
  }
  
  static const match_table_t opt_tokens = {
  	{ NVMF_OPT_TRANSPORT,		"transport=%s"		},
  	{ NVMF_OPT_TRADDR,		"traddr=%s"		},
  	{ NVMF_OPT_TRSVCID,		"trsvcid=%s"		},
  	{ NVMF_OPT_NQN,			"nqn=%s"		},
  	{ NVMF_OPT_QUEUE_SIZE,		"queue_size=%d"		},
  	{ NVMF_OPT_NR_IO_QUEUES,	"nr_io_queues=%d"	},
  	{ NVMF_OPT_RECONNECT_DELAY,	"reconnect_delay=%d"	},
  	{ NVMF_OPT_CTRL_LOSS_TMO,	"ctrl_loss_tmo=%d"	},
  	{ NVMF_OPT_KATO,		"keep_alive_tmo=%d"	},
  	{ NVMF_OPT_HOSTNQN,		"hostnqn=%s"		},
  	{ NVMF_OPT_HOST_TRADDR,		"host_traddr=%s"	},
  	{ NVMF_OPT_HOST_IFACE,		"host_iface=%s"		},
  	{ NVMF_OPT_HOST_ID,		"hostid=%s"		},
  	{ NVMF_OPT_DUP_CONNECT,		"duplicate_connect"	},
  	{ NVMF_OPT_DISABLE_SQFLOW,	"disable_sqflow"	},
  	{ NVMF_OPT_HDR_DIGEST,		"hdr_digest"		},
  	{ NVMF_OPT_DATA_DIGEST,		"data_digest"		},
  	{ NVMF_OPT_NR_WRITE_QUEUES,	"nr_write_queues=%d"	},
  	{ NVMF_OPT_NR_POLL_QUEUES,	"nr_poll_queues=%d"	},
  	{ NVMF_OPT_TOS,			"tos=%d"		},
  	{ NVMF_OPT_FAIL_FAST_TMO,	"fast_io_fail_tmo=%d"	},
  	{ NVMF_OPT_ERR,			NULL			}
  };
  
  static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
  		const char *buf)
  {
  	substring_t args[MAX_OPT_ARGS];
  	char *options, *o, *p;
  	int token, ret = 0;
  	size_t nqnlen  = 0;
  	int ctrl_loss_tmo = NVMF_DEF_CTRL_LOSS_TMO;
  	uuid_t hostid;
  
  	/* Set defaults */
  	opts->queue_size = NVMF_DEF_QUEUE_SIZE;
  	opts->nr_io_queues = num_online_cpus();
  	opts->reconnect_delay = NVMF_DEF_RECONNECT_DELAY;
  	opts->kato = 0;
  	opts->duplicate_connect = false;
  	opts->fast_io_fail_tmo = NVMF_DEF_FAIL_FAST_TMO;
  	opts->hdr_digest = false;
  	opts->data_digest = false;
  	opts->tos = -1; /* < 0 == use transport default */
  
  	options = o = kstrdup(buf, GFP_KERNEL);
  	if (!options)
  		return -ENOMEM;
  
  	uuid_gen(&hostid);
  
  	while ((p = strsep(&o, ",\n")) != NULL) {
  		if (!*p)
  			continue;
  
  		token = match_token(p, opt_tokens, args);
  		opts->mask |= token;
  		switch (token) {
  		case NVMF_OPT_TRANSPORT:
  			p = match_strdup(args);
  			if (!p) {
  				ret = -ENOMEM;
  				goto out;
  			}
  			kfree(opts->transport);
  			opts->transport = p;
  			break;
  		case NVMF_OPT_NQN:
  			p = match_strdup(args);
  			if (!p) {
  				ret = -ENOMEM;
  				goto out;
  			}
  			kfree(opts->subsysnqn);
  			opts->subsysnqn = p;
  			nqnlen = strlen(opts->subsysnqn);
  			if (nqnlen >= NVMF_NQN_SIZE) {
  				pr_err("%s needs to be < %d bytes\n",
  					opts->subsysnqn, NVMF_NQN_SIZE);
  				ret = -EINVAL;
  				goto out;
  			}
  			opts->discovery_nqn =
  				!(strcmp(opts->subsysnqn,
  					 NVME_DISC_SUBSYS_NAME));
  			break;
  		case NVMF_OPT_TRADDR:
  			p = match_strdup(args);
  			if (!p) {
  				ret = -ENOMEM;
  				goto out;
  			}
  			kfree(opts->traddr);
  			opts->traddr = p;
  			break;
  		case NVMF_OPT_TRSVCID:
  			p = match_strdup(args);
  			if (!p) {
  				ret = -ENOMEM;
  				goto out;
  			}
  			kfree(opts->trsvcid);
  			opts->trsvcid = p;
  			break;
  		case NVMF_OPT_QUEUE_SIZE:
  			if (match_int(args, &token)) {
  				ret = -EINVAL;
  				goto out;
  			}
  			if (token < NVMF_MIN_QUEUE_SIZE ||
  			    token > NVMF_MAX_QUEUE_SIZE) {
  				pr_err("Invalid queue_size %d\n", token);
  				ret = -EINVAL;
  				goto out;
  			}
  			opts->queue_size = token;
  			break;
  		case NVMF_OPT_NR_IO_QUEUES:
  			if (match_int(args, &token)) {
  				ret = -EINVAL;
  				goto out;
  			}
  			if (token <= 0) {
  				pr_err("Invalid number of IOQs %d\n", token);
  				ret = -EINVAL;
  				goto out;
  			}
  			if (opts->discovery_nqn) {
  				pr_debug("Ignoring nr_io_queues value for discovery controller\n");
  				break;
  			}
  
  			opts->nr_io_queues = min_t(unsigned int,
  					num_online_cpus(), token);
  			break;
  		case NVMF_OPT_KATO:
  			if (match_int(args, &token)) {
  				ret = -EINVAL;
  				goto out;
  			}
  
  			if (token < 0) {
  				pr_err("Invalid keep_alive_tmo %d\n", token);
  				ret = -EINVAL;
  				goto out;
  			} else if (token == 0 && !opts->discovery_nqn) {
  				/* Allowed for debug */
  				pr_warn("keep_alive_tmo 0 won't execute keep alives!!!\n");
  			}
  			opts->kato = token;
  			break;
  		case NVMF_OPT_CTRL_LOSS_TMO:
  			if (match_int(args, &token)) {
  				ret = -EINVAL;
  				goto out;
  			}
  
  			if (token < 0)
  				pr_warn("ctrl_loss_tmo < 0 will reconnect forever\n");
  			ctrl_loss_tmo = token;
  			break;
  		case NVMF_OPT_FAIL_FAST_TMO:
  			if (match_int(args, &token)) {
  				ret = -EINVAL;
  				goto out;
  			}
  
  			if (token >= 0)
  				pr_warn("I/O fail on reconnect controller after %d sec\n",
  					token);
  			opts->fast_io_fail_tmo = token;
  			break;
  		case NVMF_OPT_HOSTNQN:
  			if (opts->host) {
  				pr_err("hostnqn already user-assigned: %s\n",
  				       opts->host->nqn);
  				ret = -EADDRINUSE;
  				goto out;
  			}
  			p = match_strdup(args);
  			if (!p) {
  				ret = -ENOMEM;
  				goto out;
  			}
  			nqnlen = strlen(p);
  			if (nqnlen >= NVMF_NQN_SIZE) {
  				pr_err("%s needs to be < %d bytes\n",
  					p, NVMF_NQN_SIZE);
  				kfree(p);
  				ret = -EINVAL;
  				goto out;
  			}
  			opts->host = nvmf_host_add(p);
  			kfree(p);
  			if (!opts->host) {
  				ret = -ENOMEM;
  				goto out;
  			}
  			break;
  		case NVMF_OPT_RECONNECT_DELAY:
  			if (match_int(args, &token)) {
  				ret = -EINVAL;
  				goto out;
  			}
  			if (token <= 0) {
  				pr_err("Invalid reconnect_delay %d\n", token);
  				ret = -EINVAL;
  				goto out;
  			}
  			opts->reconnect_delay = token;
  			break;
  		case NVMF_OPT_HOST_TRADDR:
  			p = match_strdup(args);
  			if (!p) {
  				ret = -ENOMEM;
  				goto out;
  			}
  			kfree(opts->host_traddr);
  			opts->host_traddr = p;
  			break;
  		case NVMF_OPT_HOST_IFACE:
  			p = match_strdup(args);
  			if (!p) {
  				ret = -ENOMEM;
  				goto out;
  			}
  			kfree(opts->host_iface);
  			opts->host_iface = p;
  			break;
  		case NVMF_OPT_HOST_ID:
  			p = match_strdup(args);
  			if (!p) {
  				ret = -ENOMEM;
  				goto out;
  			}
  			ret = uuid_parse(p, &hostid);
  			if (ret) {
  				pr_err("Invalid hostid %s\n", p);
  				ret = -EINVAL;
  				kfree(p);
  				goto out;
  			}
  			kfree(p);
  			break;
  		case NVMF_OPT_DUP_CONNECT:
  			opts->duplicate_connect = true;
  			break;
  		case NVMF_OPT_DISABLE_SQFLOW:
  			opts->disable_sqflow = true;
  			break;
  		case NVMF_OPT_HDR_DIGEST:
  			opts->hdr_digest = true;
  			break;
  		case NVMF_OPT_DATA_DIGEST:
  			opts->data_digest = true;
  			break;
  		case NVMF_OPT_NR_WRITE_QUEUES:
  			if (match_int(args, &token)) {
  				ret = -EINVAL;
  				goto out;
  			}
  			if (token <= 0) {
  				pr_err("Invalid nr_write_queues %d\n", token);
  				ret = -EINVAL;
  				goto out;
  			}
  			opts->nr_write_queues = token;
  			break;
  		case NVMF_OPT_NR_POLL_QUEUES:
  			if (match_int(args, &token)) {
  				ret = -EINVAL;
  				goto out;
  			}
  			if (token <= 0) {
  				pr_err("Invalid nr_poll_queues %d\n", token);
  				ret = -EINVAL;
  				goto out;
  			}
  			opts->nr_poll_queues = token;
  			break;
  		case NVMF_OPT_TOS:
  			if (match_int(args, &token)) {
  				ret = -EINVAL;
  				goto out;
  			}
  			if (token < 0) {
  				pr_err("Invalid type of service %d\n", token);
  				ret = -EINVAL;
  				goto out;
  			}
  			if (token > 255) {
  				pr_warn("Clamping type of service to 255\n");
  				token = 255;
  			}
  			opts->tos = token;
  			break;
  		default:
  			pr_warn("unknown parameter or missing value '%s' in ctrl creation request\n",
  				p);
  			ret = -EINVAL;
  			goto out;
  		}
  	}
  
  	if (opts->discovery_nqn) {
  		opts->nr_io_queues = 0;
  		opts->nr_write_queues = 0;
  		opts->nr_poll_queues = 0;
  		opts->duplicate_connect = true;
  	} else {
  		if (!opts->kato)
  			opts->kato = NVME_DEFAULT_KATO;
  	}
  	if (ctrl_loss_tmo < 0) {
  		opts->max_reconnects = -1;
  	} else {
  		opts->max_reconnects = DIV_ROUND_UP(ctrl_loss_tmo,
  						opts->reconnect_delay);
  		if (ctrl_loss_tmo < opts->fast_io_fail_tmo)
  			pr_warn("failfast tmo (%d) larger than controller loss tmo (%d)\n",
  				opts->fast_io_fail_tmo, ctrl_loss_tmo);
  	}
  
  	if (!opts->host) {
  		kref_get(&nvmf_default_host->ref);
  		opts->host = nvmf_default_host;
  	}
  
  	uuid_copy(&opts->host->id, &hostid);
  
  out:
  	kfree(options);
  	return ret;
  }
  
  static int nvmf_check_required_opts(struct nvmf_ctrl_options *opts,
  		unsigned int required_opts)
  {
  	if ((opts->mask & required_opts) != required_opts) {
  		int i;
  
  		for (i = 0; i < ARRAY_SIZE(opt_tokens); i++) {
  			if ((opt_tokens[i].token & required_opts) &&
  			    !(opt_tokens[i].token & opts->mask)) {
  				pr_warn("missing parameter '%s'\n",
  					opt_tokens[i].pattern);
  			}
  		}
  
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
  		struct nvmf_ctrl_options *opts)
  {
  	if (!nvmf_ctlr_matches_baseopts(ctrl, opts) ||
  	    strcmp(opts->traddr, ctrl->opts->traddr) ||
  	    strcmp(opts->trsvcid, ctrl->opts->trsvcid))
  		return false;
  
  	/*
  	 * Checking the local address is rough. In most cases, none is specified
  	 * and the host port is selected by the stack.
  	 *
  	 * Assume no match if:
  	 * -  local address is specified and address is not the same
  	 * -  local address is not specified but remote is, or vice versa
  	 *    (admin using specific host_traddr when it matters).
  	 */
  	if ((opts->mask & NVMF_OPT_HOST_TRADDR) &&
  	    (ctrl->opts->mask & NVMF_OPT_HOST_TRADDR)) {
  		if (strcmp(opts->host_traddr, ctrl->opts->host_traddr))
  			return false;
  	} else if ((opts->mask & NVMF_OPT_HOST_TRADDR) ||
  		   (ctrl->opts->mask & NVMF_OPT_HOST_TRADDR)) {
  		return false;
  	}
  
  	return true;
  }
  EXPORT_SYMBOL_GPL(nvmf_ip_options_match);
  
  static int nvmf_check_allowed_opts(struct nvmf_ctrl_options *opts,
  		unsigned int allowed_opts)
  {
  	if (opts->mask & ~allowed_opts) {
  		int i;
  
  		for (i = 0; i < ARRAY_SIZE(opt_tokens); i++) {
  			if ((opt_tokens[i].token & opts->mask) &&
  			    (opt_tokens[i].token & ~allowed_opts)) {
  				pr_warn("invalid parameter '%s'\n",
  					opt_tokens[i].pattern);
  			}
  		}
  
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  void nvmf_free_options(struct nvmf_ctrl_options *opts)
  {
  	nvmf_host_put(opts->host);
  	kfree(opts->transport);
  	kfree(opts->traddr);
  	kfree(opts->trsvcid);
  	kfree(opts->subsysnqn);
  	kfree(opts->host_traddr);
  	kfree(opts->host_iface);
  	kfree(opts);
  }
  EXPORT_SYMBOL_GPL(nvmf_free_options);
  
  #define NVMF_REQUIRED_OPTS	(NVMF_OPT_TRANSPORT | NVMF_OPT_NQN)
  #define NVMF_ALLOWED_OPTS	(NVMF_OPT_QUEUE_SIZE | NVMF_OPT_NR_IO_QUEUES | \
  				 NVMF_OPT_KATO | NVMF_OPT_HOSTNQN | \
  				 NVMF_OPT_HOST_ID | NVMF_OPT_DUP_CONNECT |\
  				 NVMF_OPT_DISABLE_SQFLOW |\
  				 NVMF_OPT_FAIL_FAST_TMO)
  
  static struct nvme_ctrl *
  nvmf_create_ctrl(struct device *dev, const char *buf)
  {
  	struct nvmf_ctrl_options *opts;
  	struct nvmf_transport_ops *ops;
  	struct nvme_ctrl *ctrl;
  	int ret;
  
  	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
  	if (!opts)
  		return ERR_PTR(-ENOMEM);
  
  	ret = nvmf_parse_options(opts, buf);
  	if (ret)
  		goto out_free_opts;
  
  
  	request_module("nvme-%s", opts->transport);
  
  	/*
  	 * Check the generic options first as we need a valid transport for
  	 * the lookup below.  Then clear the generic flags so that transport
  	 * drivers don't have to care about them.
  	 */
  	ret = nvmf_check_required_opts(opts, NVMF_REQUIRED_OPTS);
  	if (ret)
  		goto out_free_opts;
  	opts->mask &= ~NVMF_REQUIRED_OPTS;
  
  	down_read(&nvmf_transports_rwsem);
  	ops = nvmf_lookup_transport(opts);
  	if (!ops) {
  		pr_info("no handler found for transport %s.\n",
  			opts->transport);
  		ret = -EINVAL;
  		goto out_unlock;
  	}
  
  	if (!try_module_get(ops->module)) {
  		ret = -EBUSY;
  		goto out_unlock;
  	}
  	up_read(&nvmf_transports_rwsem);
  
  	ret = nvmf_check_required_opts(opts, ops->required_opts);
  	if (ret)
  		goto out_module_put;
  	ret = nvmf_check_allowed_opts(opts, NVMF_ALLOWED_OPTS |
  				ops->allowed_opts | ops->required_opts);
  	if (ret)
  		goto out_module_put;
  
  	ctrl = ops->create_ctrl(dev, opts);
  	if (IS_ERR(ctrl)) {
  		ret = PTR_ERR(ctrl);
  		goto out_module_put;
  	}
  
  	module_put(ops->module);
  	return ctrl;
  
  out_module_put:
  	module_put(ops->module);
  	goto out_free_opts;
  out_unlock:
  	up_read(&nvmf_transports_rwsem);
  out_free_opts:
  	nvmf_free_options(opts);
  	return ERR_PTR(ret);
  }
  
  static struct class *nvmf_class;
  static struct device *nvmf_device;
  static DEFINE_MUTEX(nvmf_dev_mutex);
  
  static ssize_t nvmf_dev_write(struct file *file, const char __user *ubuf,
  		size_t count, loff_t *pos)
  {
  	struct seq_file *seq_file = file->private_data;
  	struct nvme_ctrl *ctrl;
  	const char *buf;
  	int ret = 0;
  
  	if (count > PAGE_SIZE)
  		return -ENOMEM;
  
  	buf = memdup_user_nul(ubuf, count);
  	if (IS_ERR(buf))
  		return PTR_ERR(buf);
  
  	mutex_lock(&nvmf_dev_mutex);
  	if (seq_file->private) {
  		ret = -EINVAL;
  		goto out_unlock;
  	}
  
  	ctrl = nvmf_create_ctrl(nvmf_device, buf);
  	if (IS_ERR(ctrl)) {
  		ret = PTR_ERR(ctrl);
  		goto out_unlock;
  	}
  
  	seq_file->private = ctrl;
  
  out_unlock:
  	mutex_unlock(&nvmf_dev_mutex);
  	kfree(buf);
  	return ret ? ret : count;
  }
  
  static int nvmf_dev_show(struct seq_file *seq_file, void *private)
  {
  	struct nvme_ctrl *ctrl;
  	int ret = 0;
  
  	mutex_lock(&nvmf_dev_mutex);
  	ctrl = seq_file->private;
  	if (!ctrl) {
  		ret = -EINVAL;
  		goto out_unlock;
  	}
  
  	seq_printf(seq_file, "instance=%d,cntlid=%d\n",
  			ctrl->instance, ctrl->cntlid);
  
  out_unlock:
  	mutex_unlock(&nvmf_dev_mutex);
  	return ret;
  }
  
  static int nvmf_dev_open(struct inode *inode, struct file *file)
  {
  	/*
  	 * The miscdevice code initializes file->private_data, but doesn't
  	 * make use of it later.
  	 */
  	file->private_data = NULL;
  	return single_open(file, nvmf_dev_show, NULL);
  }
  
  static int nvmf_dev_release(struct inode *inode, struct file *file)
  {
  	struct seq_file *seq_file = file->private_data;
  	struct nvme_ctrl *ctrl = seq_file->private;
  
  	if (ctrl)
  		nvme_put_ctrl(ctrl);
  	return single_release(inode, file);
  }
  
  static const struct file_operations nvmf_dev_fops = {
  	.owner		= THIS_MODULE,
  	.write		= nvmf_dev_write,
  	.read		= seq_read,
  	.open		= nvmf_dev_open,
  	.release	= nvmf_dev_release,
  };
  
  static struct miscdevice nvmf_misc = {
  	.minor		= MISC_DYNAMIC_MINOR,
  	.name           = "nvme-fabrics",
  	.fops		= &nvmf_dev_fops,
  };
  
  static int __init nvmf_init(void)
  {
  	int ret;
  
  	nvmf_default_host = nvmf_host_default();
  	if (!nvmf_default_host)
  		return -ENOMEM;
  
  	nvmf_class = class_create(THIS_MODULE, "nvme-fabrics");
  	if (IS_ERR(nvmf_class)) {
  		pr_err("couldn't register class nvme-fabrics\n");
  		ret = PTR_ERR(nvmf_class);
  		goto out_free_host;
  	}
  
  	nvmf_device =
  		device_create(nvmf_class, NULL, MKDEV(0, 0), NULL, "ctl");
  	if (IS_ERR(nvmf_device)) {
  		pr_err("couldn't create nvme-fabris device!\n");
  		ret = PTR_ERR(nvmf_device);
  		goto out_destroy_class;
  	}
  
  	ret = misc_register(&nvmf_misc);
  	if (ret) {
  		pr_err("couldn't register misc device: %d\n", ret);
  		goto out_destroy_device;
  	}
  
  	return 0;
  
  out_destroy_device:
  	device_destroy(nvmf_class, MKDEV(0, 0));
  out_destroy_class:
  	class_destroy(nvmf_class);
  out_free_host:
  	nvmf_host_put(nvmf_default_host);
  	return ret;
  }
  
  static void __exit nvmf_exit(void)
  {
  	misc_deregister(&nvmf_misc);
  	device_destroy(nvmf_class, MKDEV(0, 0));
  	class_destroy(nvmf_class);
  	nvmf_host_put(nvmf_default_host);
  
  	BUILD_BUG_ON(sizeof(struct nvmf_common_command) != 64);
  	BUILD_BUG_ON(sizeof(struct nvmf_connect_command) != 64);
  	BUILD_BUG_ON(sizeof(struct nvmf_property_get_command) != 64);
  	BUILD_BUG_ON(sizeof(struct nvmf_property_set_command) != 64);
  	BUILD_BUG_ON(sizeof(struct nvmf_connect_data) != 1024);
  }
  
  MODULE_LICENSE("GPL v2");
  
  module_init(nvmf_init);
  module_exit(nvmf_exit);
  