static int nvme_init_subsystem()

in host/core.c [2726:2812]

• 76 lines of code
• 11 McCabe index (conditional complexity)

static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
{
	struct nvme_subsystem *subsys, *found;
	int ret;

	subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
	if (!subsys)
		return -ENOMEM;

	subsys->instance = -1;
	mutex_init(&subsys->lock);
	kref_init(&subsys->ref);
	INIT_LIST_HEAD(&subsys->ctrls);
	INIT_LIST_HEAD(&subsys->nsheads);
	nvme_init_subnqn(subsys, ctrl, id);
	memcpy(subsys->serial, id->sn, sizeof(subsys->serial));
	memcpy(subsys->model, id->mn, sizeof(subsys->model));
	memcpy(subsys->firmware_rev, id->fr, sizeof(subsys->firmware_rev));
	subsys->vendor_id = le16_to_cpu(id->vid);
	subsys->cmic = id->cmic;

	/* Versions prior to 1.4 don't necessarily report a valid type */
	if (id->cntrltype == NVME_CTRL_DISC ||
	    !strcmp(subsys->subnqn, NVME_DISC_SUBSYS_NAME))
		subsys->subtype = NVME_NQN_DISC;
	else
		subsys->subtype = NVME_NQN_NVME;

	if (nvme_discovery_ctrl(ctrl) && subsys->subtype != NVME_NQN_DISC) {
		dev_err(ctrl->device,
			"Subsystem %s is not a discovery controller",
			subsys->subnqn);
		kfree(subsys);
		return -EINVAL;
	}
	subsys->awupf = le16_to_cpu(id->awupf);
	nvme_mpath_default_iopolicy(subsys);

	subsys->dev.class = nvme_subsys_class;
	subsys->dev.release = nvme_release_subsystem;
	subsys->dev.groups = nvme_subsys_attrs_groups;
	dev_set_name(&subsys->dev, "nvme-subsys%d", ctrl->instance);
	device_initialize(&subsys->dev);

	mutex_lock(&nvme_subsystems_lock);
	found = __nvme_find_get_subsystem(subsys->subnqn);
	if (found) {
		put_device(&subsys->dev);
		subsys = found;

		if (!nvme_validate_cntlid(subsys, ctrl, id)) {
			ret = -EINVAL;
			goto out_put_subsystem;
		}
	} else {
		ret = device_add(&subsys->dev);
		if (ret) {
			dev_err(ctrl->device,
				"failed to register subsystem device.\n");
			put_device(&subsys->dev);
			goto out_unlock;
		}
		ida_init(&subsys->ns_ida);
		list_add_tail(&subsys->entry, &nvme_subsystems);
	}

	ret = sysfs_create_link(&subsys->dev.kobj, &ctrl->device->kobj,
				dev_name(ctrl->device));
	if (ret) {
		dev_err(ctrl->device,
			"failed to create sysfs link from subsystem.\n");
		goto out_put_subsystem;
	}

	if (!found)
		subsys->instance = ctrl->instance;
	ctrl->subsys = subsys;
	list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
	mutex_unlock(&nvme_subsystems_lock);
	return 0;

out_put_subsystem:
	nvme_put_subsystem(subsys);
out_unlock:
	mutex_unlock(&nvme_subsystems_lock);
	return ret;
}