WIP FPC-III support

[linux/fpc-iii.git] / drivers / nvme / target / configfs.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Configfs interface for the NVMe target.
 * Copyright (c) 2015-2016 HGST, a Western Digital Company.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/ctype.h>
#include <linux/pci.h>
#include <linux/pci-p2pdma.h>

#include "nvmet.h"

static const struct config_item_type nvmet_host_type;
static const struct config_item_type nvmet_subsys_type;

static LIST_HEAD(nvmet_ports_list);
struct list_head *nvmet_ports = &nvmet_ports_list;

struct nvmet_type_name_map {
        u8              type;
        const char      *name;
};

static struct nvmet_type_name_map nvmet_transport[] = {
        { NVMF_TRTYPE_RDMA,     "rdma" },
        { NVMF_TRTYPE_FC,       "fc" },
        { NVMF_TRTYPE_TCP,      "tcp" },
        { NVMF_TRTYPE_LOOP,     "loop" },
};

static const struct nvmet_type_name_map nvmet_addr_family[] = {
        { NVMF_ADDR_FAMILY_PCI,         "pcie" },
        { NVMF_ADDR_FAMILY_IP4,         "ipv4" },
        { NVMF_ADDR_FAMILY_IP6,         "ipv6" },
        { NVMF_ADDR_FAMILY_IB,          "ib" },
        { NVMF_ADDR_FAMILY_FC,          "fc" },
        { NVMF_ADDR_FAMILY_LOOP,        "loop" },
};

static bool nvmet_is_port_enabled(struct nvmet_port *p, const char *caller)
{
        if (p->enabled)
                pr_err("Disable port '%u' before changing attribute in %s\n",
                                le16_to_cpu(p->disc_addr.portid), caller);
        return p->enabled;
}

/*
 * nvmet_port Generic ConfigFS definitions.
 * Used in any place in the ConfigFS tree that refers to an address.
 */
static ssize_t nvmet_addr_adrfam_show(struct config_item *item, char *page)
{
        u8 adrfam = to_nvmet_port(item)->disc_addr.adrfam;
        int i;

        for (i = 1; i < ARRAY_SIZE(nvmet_addr_family); i++) {
                if (nvmet_addr_family[i].type == adrfam)
                        return sprintf(page, "%s\n", nvmet_addr_family[i].name);
        }

        return sprintf(page, "\n");
}

static ssize_t nvmet_addr_adrfam_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_port *port = to_nvmet_port(item);
        int i;

        if (nvmet_is_port_enabled(port, __func__))
                return -EACCES;

        for (i = 1; i < ARRAY_SIZE(nvmet_addr_family); i++) {
                if (sysfs_streq(page, nvmet_addr_family[i].name))
                        goto found;
        }

        pr_err("Invalid value '%s' for adrfam\n", page);
        return -EINVAL;

found:
        port->disc_addr.adrfam = nvmet_addr_family[i].type;
        return count;
}

CONFIGFS_ATTR(nvmet_, addr_adrfam);

static ssize_t nvmet_addr_portid_show(struct config_item *item,
                char *page)
{
        struct nvmet_port *port = to_nvmet_port(item);

        return snprintf(page, PAGE_SIZE, "%d\n",
                        le16_to_cpu(port->disc_addr.portid));
}

static ssize_t nvmet_addr_portid_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_port *port = to_nvmet_port(item);
        u16 portid = 0;

        if (kstrtou16(page, 0, &portid)) {
                pr_err("Invalid value '%s' for portid\n", page);
                return -EINVAL;
        }

        if (nvmet_is_port_enabled(port, __func__))
                return -EACCES;

        port->disc_addr.portid = cpu_to_le16(portid);
        return count;
}

CONFIGFS_ATTR(nvmet_, addr_portid);

static ssize_t nvmet_addr_traddr_show(struct config_item *item,
                char *page)
{
        struct nvmet_port *port = to_nvmet_port(item);

        return snprintf(page, PAGE_SIZE, "%s\n",
                        port->disc_addr.traddr);
}

static ssize_t nvmet_addr_traddr_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_port *port = to_nvmet_port(item);

        if (count > NVMF_TRADDR_SIZE) {
                pr_err("Invalid value '%s' for traddr\n", page);
                return -EINVAL;
        }

        if (nvmet_is_port_enabled(port, __func__))
                return -EACCES;

        if (sscanf(page, "%s\n", port->disc_addr.traddr) != 1)
                return -EINVAL;
        return count;
}

CONFIGFS_ATTR(nvmet_, addr_traddr);

static const struct nvmet_type_name_map nvmet_addr_treq[] = {
        { NVMF_TREQ_NOT_SPECIFIED,      "not specified" },
        { NVMF_TREQ_REQUIRED,           "required" },
        { NVMF_TREQ_NOT_REQUIRED,       "not required" },
};

static ssize_t nvmet_addr_treq_show(struct config_item *item, char *page)
{
        u8 treq = to_nvmet_port(item)->disc_addr.treq &
                NVME_TREQ_SECURE_CHANNEL_MASK;
        int i;

        for (i = 0; i < ARRAY_SIZE(nvmet_addr_treq); i++) {
                if (treq == nvmet_addr_treq[i].type)
                        return sprintf(page, "%s\n", nvmet_addr_treq[i].name);
        }

        return sprintf(page, "\n");
}

static ssize_t nvmet_addr_treq_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_port *port = to_nvmet_port(item);
        u8 treq = port->disc_addr.treq & ~NVME_TREQ_SECURE_CHANNEL_MASK;
        int i;

        if (nvmet_is_port_enabled(port, __func__))
                return -EACCES;

        for (i = 0; i < ARRAY_SIZE(nvmet_addr_treq); i++) {
                if (sysfs_streq(page, nvmet_addr_treq[i].name))
                        goto found;
        }

        pr_err("Invalid value '%s' for treq\n", page);
        return -EINVAL;

found:
        treq |= nvmet_addr_treq[i].type;
        port->disc_addr.treq = treq;
        return count;
}

CONFIGFS_ATTR(nvmet_, addr_treq);

static ssize_t nvmet_addr_trsvcid_show(struct config_item *item,
                char *page)
{
        struct nvmet_port *port = to_nvmet_port(item);

        return snprintf(page, PAGE_SIZE, "%s\n",
                        port->disc_addr.trsvcid);
}

static ssize_t nvmet_addr_trsvcid_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_port *port = to_nvmet_port(item);

        if (count > NVMF_TRSVCID_SIZE) {
                pr_err("Invalid value '%s' for trsvcid\n", page);
                return -EINVAL;
        }
        if (nvmet_is_port_enabled(port, __func__))
                return -EACCES;

        if (sscanf(page, "%s\n", port->disc_addr.trsvcid) != 1)
                return -EINVAL;
        return count;
}

CONFIGFS_ATTR(nvmet_, addr_trsvcid);

static ssize_t nvmet_param_inline_data_size_show(struct config_item *item,
                char *page)
{
        struct nvmet_port *port = to_nvmet_port(item);

        return snprintf(page, PAGE_SIZE, "%d\n", port->inline_data_size);
}

static ssize_t nvmet_param_inline_data_size_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_port *port = to_nvmet_port(item);
        int ret;

        if (nvmet_is_port_enabled(port, __func__))
                return -EACCES;
        ret = kstrtoint(page, 0, &port->inline_data_size);
        if (ret) {
                pr_err("Invalid value '%s' for inline_data_size\n", page);
                return -EINVAL;
        }
        return count;
}

CONFIGFS_ATTR(nvmet_, param_inline_data_size);

#ifdef CONFIG_BLK_DEV_INTEGRITY
static ssize_t nvmet_param_pi_enable_show(struct config_item *item,
                char *page)
{
        struct nvmet_port *port = to_nvmet_port(item);

        return snprintf(page, PAGE_SIZE, "%d\n", port->pi_enable);
}

static ssize_t nvmet_param_pi_enable_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_port *port = to_nvmet_port(item);
        bool val;

        if (strtobool(page, &val))
                return -EINVAL;

        if (port->enabled) {
                pr_err("Disable port before setting pi_enable value.\n");
                return -EACCES;
        }

        port->pi_enable = val;
        return count;
}

CONFIGFS_ATTR(nvmet_, param_pi_enable);
#endif

static ssize_t nvmet_addr_trtype_show(struct config_item *item,
                char *page)
{
        struct nvmet_port *port = to_nvmet_port(item);
        int i;

        for (i = 0; i < ARRAY_SIZE(nvmet_transport); i++) {
                if (port->disc_addr.trtype == nvmet_transport[i].type)
                        return sprintf(page, "%s\n", nvmet_transport[i].name);
        }

        return sprintf(page, "\n");
}

static void nvmet_port_init_tsas_rdma(struct nvmet_port *port)
{
        port->disc_addr.tsas.rdma.qptype = NVMF_RDMA_QPTYPE_CONNECTED;
        port->disc_addr.tsas.rdma.prtype = NVMF_RDMA_PRTYPE_NOT_SPECIFIED;
        port->disc_addr.tsas.rdma.cms = NVMF_RDMA_CMS_RDMA_CM;
}

static ssize_t nvmet_addr_trtype_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_port *port = to_nvmet_port(item);
        int i;

        if (nvmet_is_port_enabled(port, __func__))
                return -EACCES;

        for (i = 0; i < ARRAY_SIZE(nvmet_transport); i++) {
                if (sysfs_streq(page, nvmet_transport[i].name))
                        goto found;
        }

        pr_err("Invalid value '%s' for trtype\n", page);
        return -EINVAL;

found:
        memset(&port->disc_addr.tsas, 0, NVMF_TSAS_SIZE);
        port->disc_addr.trtype = nvmet_transport[i].type;
        if (port->disc_addr.trtype == NVMF_TRTYPE_RDMA)
                nvmet_port_init_tsas_rdma(port);
        return count;
}

CONFIGFS_ATTR(nvmet_, addr_trtype);

/*
 * Namespace structures & file operation functions below
 */
static ssize_t nvmet_ns_device_path_show(struct config_item *item, char *page)
{
        return sprintf(page, "%s\n", to_nvmet_ns(item)->device_path);
}

static ssize_t nvmet_ns_device_path_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_ns *ns = to_nvmet_ns(item);
        struct nvmet_subsys *subsys = ns->subsys;
        size_t len;
        int ret;

        mutex_lock(&subsys->lock);
        ret = -EBUSY;
        if (ns->enabled)
                goto out_unlock;

        ret = -EINVAL;
        len = strcspn(page, "\n");
        if (!len)
                goto out_unlock;

        kfree(ns->device_path);
        ret = -ENOMEM;
        ns->device_path = kmemdup_nul(page, len, GFP_KERNEL);
        if (!ns->device_path)
                goto out_unlock;

        mutex_unlock(&subsys->lock);
        return count;

out_unlock:
        mutex_unlock(&subsys->lock);
        return ret;
}

CONFIGFS_ATTR(nvmet_ns_, device_path);

#ifdef CONFIG_PCI_P2PDMA
static ssize_t nvmet_ns_p2pmem_show(struct config_item *item, char *page)
{
        struct nvmet_ns *ns = to_nvmet_ns(item);

        return pci_p2pdma_enable_show(page, ns->p2p_dev, ns->use_p2pmem);
}

static ssize_t nvmet_ns_p2pmem_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_ns *ns = to_nvmet_ns(item);
        struct pci_dev *p2p_dev = NULL;
        bool use_p2pmem;
        int ret = count;
        int error;

        mutex_lock(&ns->subsys->lock);
        if (ns->enabled) {
                ret = -EBUSY;
                goto out_unlock;
        }

        error = pci_p2pdma_enable_store(page, &p2p_dev, &use_p2pmem);
        if (error) {
                ret = error;
                goto out_unlock;
        }

        ns->use_p2pmem = use_p2pmem;
        pci_dev_put(ns->p2p_dev);
        ns->p2p_dev = p2p_dev;

out_unlock:
        mutex_unlock(&ns->subsys->lock);

        return ret;
}

CONFIGFS_ATTR(nvmet_ns_, p2pmem);
#endif /* CONFIG_PCI_P2PDMA */

static ssize_t nvmet_ns_device_uuid_show(struct config_item *item, char *page)
{
        return sprintf(page, "%pUb\n", &to_nvmet_ns(item)->uuid);
}

static ssize_t nvmet_ns_device_uuid_store(struct config_item *item,
                                          const char *page, size_t count)
{
        struct nvmet_ns *ns = to_nvmet_ns(item);
        struct nvmet_subsys *subsys = ns->subsys;
        int ret = 0;

        mutex_lock(&subsys->lock);
        if (ns->enabled) {
                ret = -EBUSY;
                goto out_unlock;
        }

        if (uuid_parse(page, &ns->uuid))
                ret = -EINVAL;

out_unlock:
        mutex_unlock(&subsys->lock);
        return ret ? ret : count;
}

CONFIGFS_ATTR(nvmet_ns_, device_uuid);

static ssize_t nvmet_ns_device_nguid_show(struct config_item *item, char *page)
{
        return sprintf(page, "%pUb\n", &to_nvmet_ns(item)->nguid);
}

static ssize_t nvmet_ns_device_nguid_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_ns *ns = to_nvmet_ns(item);
        struct nvmet_subsys *subsys = ns->subsys;
        u8 nguid[16];
        const char *p = page;
        int i;
        int ret = 0;

        mutex_lock(&subsys->lock);
        if (ns->enabled) {
                ret = -EBUSY;
                goto out_unlock;
        }

        for (i = 0; i < 16; i++) {
                if (p + 2 > page + count) {
                        ret = -EINVAL;
                        goto out_unlock;
                }
                if (!isxdigit(p[0]) || !isxdigit(p[1])) {
                        ret = -EINVAL;
                        goto out_unlock;
                }

                nguid[i] = (hex_to_bin(p[0]) << 4) | hex_to_bin(p[1]);
                p += 2;

                if (*p == '-' || *p == ':')
                        p++;
        }

        memcpy(&ns->nguid, nguid, sizeof(nguid));
out_unlock:
        mutex_unlock(&subsys->lock);
        return ret ? ret : count;
}

CONFIGFS_ATTR(nvmet_ns_, device_nguid);

static ssize_t nvmet_ns_ana_grpid_show(struct config_item *item, char *page)
{
        return sprintf(page, "%u\n", to_nvmet_ns(item)->anagrpid);
}

static ssize_t nvmet_ns_ana_grpid_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_ns *ns = to_nvmet_ns(item);
        u32 oldgrpid, newgrpid;
        int ret;

        ret = kstrtou32(page, 0, &newgrpid);
        if (ret)
                return ret;

        if (newgrpid < 1 || newgrpid > NVMET_MAX_ANAGRPS)
                return -EINVAL;

        down_write(&nvmet_ana_sem);
        oldgrpid = ns->anagrpid;
        nvmet_ana_group_enabled[newgrpid]++;
        ns->anagrpid = newgrpid;
        nvmet_ana_group_enabled[oldgrpid]--;
        nvmet_ana_chgcnt++;
        up_write(&nvmet_ana_sem);

        nvmet_send_ana_event(ns->subsys, NULL);
        return count;
}

CONFIGFS_ATTR(nvmet_ns_, ana_grpid);

static ssize_t nvmet_ns_enable_show(struct config_item *item, char *page)
{
        return sprintf(page, "%d\n", to_nvmet_ns(item)->enabled);
}

static ssize_t nvmet_ns_enable_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_ns *ns = to_nvmet_ns(item);
        bool enable;
        int ret = 0;

        if (strtobool(page, &enable))
                return -EINVAL;

        if (enable)
                ret = nvmet_ns_enable(ns);
        else
                nvmet_ns_disable(ns);

        return ret ? ret : count;
}

CONFIGFS_ATTR(nvmet_ns_, enable);

static ssize_t nvmet_ns_buffered_io_show(struct config_item *item, char *page)
{
        return sprintf(page, "%d\n", to_nvmet_ns(item)->buffered_io);
}

static ssize_t nvmet_ns_buffered_io_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_ns *ns = to_nvmet_ns(item);
        bool val;

        if (strtobool(page, &val))
                return -EINVAL;

        mutex_lock(&ns->subsys->lock);
        if (ns->enabled) {
                pr_err("disable ns before setting buffered_io value.\n");
                mutex_unlock(&ns->subsys->lock);
                return -EINVAL;
        }

        ns->buffered_io = val;
        mutex_unlock(&ns->subsys->lock);
        return count;
}

CONFIGFS_ATTR(nvmet_ns_, buffered_io);

static ssize_t nvmet_ns_revalidate_size_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_ns *ns = to_nvmet_ns(item);
        bool val;

        if (strtobool(page, &val))
                return -EINVAL;

        if (!val)
                return -EINVAL;

        mutex_lock(&ns->subsys->lock);
        if (!ns->enabled) {
                pr_err("enable ns before revalidate.\n");
                mutex_unlock(&ns->subsys->lock);
                return -EINVAL;
        }
        nvmet_ns_revalidate(ns);
        mutex_unlock(&ns->subsys->lock);
        return count;
}

CONFIGFS_ATTR_WO(nvmet_ns_, revalidate_size);

static struct configfs_attribute *nvmet_ns_attrs[] = {
        &nvmet_ns_attr_device_path,
        &nvmet_ns_attr_device_nguid,
        &nvmet_ns_attr_device_uuid,
        &nvmet_ns_attr_ana_grpid,
        &nvmet_ns_attr_enable,
        &nvmet_ns_attr_buffered_io,
        &nvmet_ns_attr_revalidate_size,
#ifdef CONFIG_PCI_P2PDMA
        &nvmet_ns_attr_p2pmem,
#endif
        NULL,
};

static void nvmet_ns_release(struct config_item *item)
{
        struct nvmet_ns *ns = to_nvmet_ns(item);

        nvmet_ns_free(ns);
}

static struct configfs_item_operations nvmet_ns_item_ops = {
        .release                = nvmet_ns_release,
};

static const struct config_item_type nvmet_ns_type = {
        .ct_item_ops            = &nvmet_ns_item_ops,
        .ct_attrs               = nvmet_ns_attrs,
        .ct_owner               = THIS_MODULE,
};

static struct config_group *nvmet_ns_make(struct config_group *group,
                const char *name)
{
        struct nvmet_subsys *subsys = namespaces_to_subsys(&group->cg_item);
        struct nvmet_ns *ns;
        int ret;
        u32 nsid;

        ret = kstrtou32(name, 0, &nsid);
        if (ret)
                goto out;

        ret = -EINVAL;
        if (nsid == 0 || nsid == NVME_NSID_ALL) {
                pr_err("invalid nsid %#x", nsid);
                goto out;
        }

        ret = -ENOMEM;
        ns = nvmet_ns_alloc(subsys, nsid);
        if (!ns)
                goto out;
        config_group_init_type_name(&ns->group, name, &nvmet_ns_type);

        pr_info("adding nsid %d to subsystem %s\n", nsid, subsys->subsysnqn);

        return &ns->group;
out:
        return ERR_PTR(ret);
}

static struct configfs_group_operations nvmet_namespaces_group_ops = {
        .make_group             = nvmet_ns_make,
};

static const struct config_item_type nvmet_namespaces_type = {
        .ct_group_ops           = &nvmet_namespaces_group_ops,
        .ct_owner               = THIS_MODULE,
};

#ifdef CONFIG_NVME_TARGET_PASSTHRU

static ssize_t nvmet_passthru_device_path_show(struct config_item *item,
                char *page)
{
        struct nvmet_subsys *subsys = to_subsys(item->ci_parent);

        return snprintf(page, PAGE_SIZE, "%s\n", subsys->passthru_ctrl_path);
}

static ssize_t nvmet_passthru_device_path_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
        size_t len;
        int ret;

        mutex_lock(&subsys->lock);

        ret = -EBUSY;
        if (subsys->passthru_ctrl)
                goto out_unlock;

        ret = -EINVAL;
        len = strcspn(page, "\n");
        if (!len)
                goto out_unlock;

        kfree(subsys->passthru_ctrl_path);
        ret = -ENOMEM;
        subsys->passthru_ctrl_path = kstrndup(page, len, GFP_KERNEL);
        if (!subsys->passthru_ctrl_path)
                goto out_unlock;

        mutex_unlock(&subsys->lock);

        return count;
out_unlock:
        mutex_unlock(&subsys->lock);
        return ret;
}
CONFIGFS_ATTR(nvmet_passthru_, device_path);

static ssize_t nvmet_passthru_enable_show(struct config_item *item,
                char *page)
{
        struct nvmet_subsys *subsys = to_subsys(item->ci_parent);

        return sprintf(page, "%d\n", subsys->passthru_ctrl ? 1 : 0);
}

static ssize_t nvmet_passthru_enable_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
        bool enable;
        int ret = 0;

        if (strtobool(page, &enable))
                return -EINVAL;

        if (enable)
                ret = nvmet_passthru_ctrl_enable(subsys);
        else
                nvmet_passthru_ctrl_disable(subsys);

        return ret ? ret : count;
}
CONFIGFS_ATTR(nvmet_passthru_, enable);

static ssize_t nvmet_passthru_admin_timeout_show(struct config_item *item,
                char *page)
{
        return sprintf(page, "%u\n", to_subsys(item->ci_parent)->admin_timeout);
}

static ssize_t nvmet_passthru_admin_timeout_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
        unsigned int timeout;

        if (kstrtouint(page, 0, &timeout))
                return -EINVAL;
        subsys->admin_timeout = timeout;
        return count;
}
CONFIGFS_ATTR(nvmet_passthru_, admin_timeout);

static ssize_t nvmet_passthru_io_timeout_show(struct config_item *item,
                char *page)
{
        return sprintf(page, "%u\n", to_subsys(item->ci_parent)->io_timeout);
}

static ssize_t nvmet_passthru_io_timeout_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_subsys *subsys = to_subsys(item->ci_parent);
        unsigned int timeout;

        if (kstrtouint(page, 0, &timeout))
                return -EINVAL;
        subsys->io_timeout = timeout;
        return count;
}
CONFIGFS_ATTR(nvmet_passthru_, io_timeout);

static struct configfs_attribute *nvmet_passthru_attrs[] = {
        &nvmet_passthru_attr_device_path,
        &nvmet_passthru_attr_enable,
        &nvmet_passthru_attr_admin_timeout,
        &nvmet_passthru_attr_io_timeout,
        NULL,
};

static const struct config_item_type nvmet_passthru_type = {
        .ct_attrs               = nvmet_passthru_attrs,
        .ct_owner               = THIS_MODULE,
};

static void nvmet_add_passthru_group(struct nvmet_subsys *subsys)
{
        config_group_init_type_name(&subsys->passthru_group,
                                    "passthru", &nvmet_passthru_type);
        configfs_add_default_group(&subsys->passthru_group,
                                   &subsys->group);
}

#else /* CONFIG_NVME_TARGET_PASSTHRU */

static void nvmet_add_passthru_group(struct nvmet_subsys *subsys)
{
}

#endif /* CONFIG_NVME_TARGET_PASSTHRU */

static int nvmet_port_subsys_allow_link(struct config_item *parent,
                struct config_item *target)
{
        struct nvmet_port *port = to_nvmet_port(parent->ci_parent);
        struct nvmet_subsys *subsys;
        struct nvmet_subsys_link *link, *p;
        int ret;

        if (target->ci_type != &nvmet_subsys_type) {
                pr_err("can only link subsystems into the subsystems dir.!\n");
                return -EINVAL;
        }
        subsys = to_subsys(target);
        link = kmalloc(sizeof(*link), GFP_KERNEL);
        if (!link)
                return -ENOMEM;
        link->subsys = subsys;

        down_write(&nvmet_config_sem);
        ret = -EEXIST;
        list_for_each_entry(p, &port->subsystems, entry) {
                if (p->subsys == subsys)
                        goto out_free_link;
        }

        if (list_empty(&port->subsystems)) {
                ret = nvmet_enable_port(port);
                if (ret)
                        goto out_free_link;
        }

        list_add_tail(&link->entry, &port->subsystems);
        nvmet_port_disc_changed(port, subsys);

        up_write(&nvmet_config_sem);
        return 0;

out_free_link:
        up_write(&nvmet_config_sem);
        kfree(link);
        return ret;
}

static void nvmet_port_subsys_drop_link(struct config_item *parent,
                struct config_item *target)
{
        struct nvmet_port *port = to_nvmet_port(parent->ci_parent);
        struct nvmet_subsys *subsys = to_subsys(target);
        struct nvmet_subsys_link *p;

        down_write(&nvmet_config_sem);
        list_for_each_entry(p, &port->subsystems, entry) {
                if (p->subsys == subsys)
                        goto found;
        }
        up_write(&nvmet_config_sem);
        return;

found:
        list_del(&p->entry);
        nvmet_port_del_ctrls(port, subsys);
        nvmet_port_disc_changed(port, subsys);

        if (list_empty(&port->subsystems))
                nvmet_disable_port(port);
        up_write(&nvmet_config_sem);
        kfree(p);
}

static struct configfs_item_operations nvmet_port_subsys_item_ops = {
        .allow_link             = nvmet_port_subsys_allow_link,
        .drop_link              = nvmet_port_subsys_drop_link,
};

static const struct config_item_type nvmet_port_subsys_type = {
        .ct_item_ops            = &nvmet_port_subsys_item_ops,
        .ct_owner               = THIS_MODULE,
};

static int nvmet_allowed_hosts_allow_link(struct config_item *parent,
                struct config_item *target)
{
        struct nvmet_subsys *subsys = to_subsys(parent->ci_parent);
        struct nvmet_host *host;
        struct nvmet_host_link *link, *p;
        int ret;

        if (target->ci_type != &nvmet_host_type) {
                pr_err("can only link hosts into the allowed_hosts directory!\n");
                return -EINVAL;
        }

        host = to_host(target);
        link = kmalloc(sizeof(*link), GFP_KERNEL);
        if (!link)
                return -ENOMEM;
        link->host = host;

        down_write(&nvmet_config_sem);
        ret = -EINVAL;
        if (subsys->allow_any_host) {
                pr_err("can't add hosts when allow_any_host is set!\n");
                goto out_free_link;
        }

        ret = -EEXIST;
        list_for_each_entry(p, &subsys->hosts, entry) {
                if (!strcmp(nvmet_host_name(p->host), nvmet_host_name(host)))
                        goto out_free_link;
        }
        list_add_tail(&link->entry, &subsys->hosts);
        nvmet_subsys_disc_changed(subsys, host);

        up_write(&nvmet_config_sem);
        return 0;
out_free_link:
        up_write(&nvmet_config_sem);
        kfree(link);
        return ret;
}

static void nvmet_allowed_hosts_drop_link(struct config_item *parent,
                struct config_item *target)
{
        struct nvmet_subsys *subsys = to_subsys(parent->ci_parent);
        struct nvmet_host *host = to_host(target);
        struct nvmet_host_link *p;

        down_write(&nvmet_config_sem);
        list_for_each_entry(p, &subsys->hosts, entry) {
                if (!strcmp(nvmet_host_name(p->host), nvmet_host_name(host)))
                        goto found;
        }
        up_write(&nvmet_config_sem);
        return;

found:
        list_del(&p->entry);
        nvmet_subsys_disc_changed(subsys, host);

        up_write(&nvmet_config_sem);
        kfree(p);
}

static struct configfs_item_operations nvmet_allowed_hosts_item_ops = {
        .allow_link             = nvmet_allowed_hosts_allow_link,
        .drop_link              = nvmet_allowed_hosts_drop_link,
};

static const struct config_item_type nvmet_allowed_hosts_type = {
        .ct_item_ops            = &nvmet_allowed_hosts_item_ops,
        .ct_owner               = THIS_MODULE,
};

static ssize_t nvmet_subsys_attr_allow_any_host_show(struct config_item *item,
                char *page)
{
        return snprintf(page, PAGE_SIZE, "%d\n",
                to_subsys(item)->allow_any_host);
}

static ssize_t nvmet_subsys_attr_allow_any_host_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_subsys *subsys = to_subsys(item);
        bool allow_any_host;
        int ret = 0;

        if (strtobool(page, &allow_any_host))
                return -EINVAL;

        down_write(&nvmet_config_sem);
        if (allow_any_host && !list_empty(&subsys->hosts)) {
                pr_err("Can't set allow_any_host when explicit hosts are set!\n");
                ret = -EINVAL;
                goto out_unlock;
        }

        if (subsys->allow_any_host != allow_any_host) {
                subsys->allow_any_host = allow_any_host;
                nvmet_subsys_disc_changed(subsys, NULL);
        }

out_unlock:
        up_write(&nvmet_config_sem);
        return ret ? ret : count;
}

CONFIGFS_ATTR(nvmet_subsys_, attr_allow_any_host);

static ssize_t nvmet_subsys_attr_version_show(struct config_item *item,
                                              char *page)
{
        struct nvmet_subsys *subsys = to_subsys(item);

        if (NVME_TERTIARY(subsys->ver))
                return snprintf(page, PAGE_SIZE, "%llu.%llu.%llu\n",
                                NVME_MAJOR(subsys->ver),
                                NVME_MINOR(subsys->ver),
                                NVME_TERTIARY(subsys->ver));

        return snprintf(page, PAGE_SIZE, "%llu.%llu\n",
                        NVME_MAJOR(subsys->ver),
                        NVME_MINOR(subsys->ver));
}

static ssize_t nvmet_subsys_attr_version_store(struct config_item *item,
                                               const char *page, size_t count)
{
        struct nvmet_subsys *subsys = to_subsys(item);
        int major, minor, tertiary = 0;
        int ret;

        /* passthru subsystems use the underlying controller's version */
        if (nvmet_passthru_ctrl(subsys))
                return -EINVAL;

        ret = sscanf(page, "%d.%d.%d\n", &major, &minor, &tertiary);
        if (ret != 2 && ret != 3)
                return -EINVAL;

        down_write(&nvmet_config_sem);
        subsys->ver = NVME_VS(major, minor, tertiary);
        up_write(&nvmet_config_sem);

        return count;
}
CONFIGFS_ATTR(nvmet_subsys_, attr_version);

static ssize_t nvmet_subsys_attr_serial_show(struct config_item *item,
                                             char *page)
{
        struct nvmet_subsys *subsys = to_subsys(item);

        return snprintf(page, PAGE_SIZE, "%llx\n", subsys->serial);
}

static ssize_t nvmet_subsys_attr_serial_store(struct config_item *item,
                                              const char *page, size_t count)
{
        u64 serial;

        if (sscanf(page, "%llx\n", &serial) != 1)
                return -EINVAL;

        down_write(&nvmet_config_sem);
        to_subsys(item)->serial = serial;
        up_write(&nvmet_config_sem);

        return count;
}
CONFIGFS_ATTR(nvmet_subsys_, attr_serial);

static ssize_t nvmet_subsys_attr_cntlid_min_show(struct config_item *item,
                                                 char *page)
{
        return snprintf(page, PAGE_SIZE, "%u\n", to_subsys(item)->cntlid_min);
}

static ssize_t nvmet_subsys_attr_cntlid_min_store(struct config_item *item,
                                                  const char *page, size_t cnt)
{
        u16 cntlid_min;

        if (sscanf(page, "%hu\n", &cntlid_min) != 1)
                return -EINVAL;

        if (cntlid_min == 0)
                return -EINVAL;

        down_write(&nvmet_config_sem);
        if (cntlid_min >= to_subsys(item)->cntlid_max)
                goto out_unlock;
        to_subsys(item)->cntlid_min = cntlid_min;
        up_write(&nvmet_config_sem);
        return cnt;

out_unlock:
        up_write(&nvmet_config_sem);
        return -EINVAL;
}
CONFIGFS_ATTR(nvmet_subsys_, attr_cntlid_min);

static ssize_t nvmet_subsys_attr_cntlid_max_show(struct config_item *item,
                                                 char *page)
{
        return snprintf(page, PAGE_SIZE, "%u\n", to_subsys(item)->cntlid_max);
}

static ssize_t nvmet_subsys_attr_cntlid_max_store(struct config_item *item,
                                                  const char *page, size_t cnt)
{
        u16 cntlid_max;

        if (sscanf(page, "%hu\n", &cntlid_max) != 1)
                return -EINVAL;

        if (cntlid_max == 0)
                return -EINVAL;

        down_write(&nvmet_config_sem);
        if (cntlid_max <= to_subsys(item)->cntlid_min)
                goto out_unlock;
        to_subsys(item)->cntlid_max = cntlid_max;
        up_write(&nvmet_config_sem);
        return cnt;

out_unlock:
        up_write(&nvmet_config_sem);
        return -EINVAL;
}
CONFIGFS_ATTR(nvmet_subsys_, attr_cntlid_max);

static ssize_t nvmet_subsys_attr_model_show(struct config_item *item,
                                            char *page)
{
        struct nvmet_subsys *subsys = to_subsys(item);
        struct nvmet_subsys_model *subsys_model;
        char *model = NVMET_DEFAULT_CTRL_MODEL;
        int ret;

        rcu_read_lock();
        subsys_model = rcu_dereference(subsys->model);
        if (subsys_model)
                model = subsys_model->number;
        ret = snprintf(page, PAGE_SIZE, "%s\n", model);
        rcu_read_unlock();

        return ret;
}

/* See Section 1.5 of NVMe 1.4 */
static bool nvmet_is_ascii(const char c)
{
        return c >= 0x20 && c <= 0x7e;
}

static ssize_t nvmet_subsys_attr_model_store(struct config_item *item,
                                             const char *page, size_t count)
{
        struct nvmet_subsys *subsys = to_subsys(item);
        struct nvmet_subsys_model *new_model;
        char *new_model_number;
        int pos = 0, len;

        len = strcspn(page, "\n");
        if (!len)
                return -EINVAL;

        for (pos = 0; pos < len; pos++) {
                if (!nvmet_is_ascii(page[pos]))
                        return -EINVAL;
        }

        new_model_number = kmemdup_nul(page, len, GFP_KERNEL);
        if (!new_model_number)
                return -ENOMEM;

        new_model = kzalloc(sizeof(*new_model) + len + 1, GFP_KERNEL);
        if (!new_model) {
                kfree(new_model_number);
                return -ENOMEM;
        }
        memcpy(new_model->number, new_model_number, len);

        down_write(&nvmet_config_sem);
        mutex_lock(&subsys->lock);
        new_model = rcu_replace_pointer(subsys->model, new_model,
                                        mutex_is_locked(&subsys->lock));
        mutex_unlock(&subsys->lock);
        up_write(&nvmet_config_sem);

        kfree_rcu(new_model, rcuhead);
        kfree(new_model_number);

        return count;
}
CONFIGFS_ATTR(nvmet_subsys_, attr_model);

#ifdef CONFIG_BLK_DEV_INTEGRITY
static ssize_t nvmet_subsys_attr_pi_enable_show(struct config_item *item,
                                                char *page)
{
        return snprintf(page, PAGE_SIZE, "%d\n", to_subsys(item)->pi_support);
}

static ssize_t nvmet_subsys_attr_pi_enable_store(struct config_item *item,
                                                 const char *page, size_t count)
{
        struct nvmet_subsys *subsys = to_subsys(item);
        bool pi_enable;

        if (strtobool(page, &pi_enable))
                return -EINVAL;

        subsys->pi_support = pi_enable;
        return count;
}
CONFIGFS_ATTR(nvmet_subsys_, attr_pi_enable);
#endif

static struct configfs_attribute *nvmet_subsys_attrs[] = {
        &nvmet_subsys_attr_attr_allow_any_host,
        &nvmet_subsys_attr_attr_version,
        &nvmet_subsys_attr_attr_serial,
        &nvmet_subsys_attr_attr_cntlid_min,
        &nvmet_subsys_attr_attr_cntlid_max,
        &nvmet_subsys_attr_attr_model,
#ifdef CONFIG_BLK_DEV_INTEGRITY
        &nvmet_subsys_attr_attr_pi_enable,
#endif
        NULL,
};

/*
 * Subsystem structures & folder operation functions below
 */
static void nvmet_subsys_release(struct config_item *item)
{
        struct nvmet_subsys *subsys = to_subsys(item);

        nvmet_subsys_del_ctrls(subsys);
        nvmet_subsys_put(subsys);
}

static struct configfs_item_operations nvmet_subsys_item_ops = {
        .release                = nvmet_subsys_release,
};

static const struct config_item_type nvmet_subsys_type = {
        .ct_item_ops            = &nvmet_subsys_item_ops,
        .ct_attrs               = nvmet_subsys_attrs,
        .ct_owner               = THIS_MODULE,
};

static struct config_group *nvmet_subsys_make(struct config_group *group,
                const char *name)
{
        struct nvmet_subsys *subsys;

        if (sysfs_streq(name, NVME_DISC_SUBSYS_NAME)) {
                pr_err("can't create discovery subsystem through configfs\n");
                return ERR_PTR(-EINVAL);
        }

        subsys = nvmet_subsys_alloc(name, NVME_NQN_NVME);
        if (IS_ERR(subsys))
                return ERR_CAST(subsys);

        config_group_init_type_name(&subsys->group, name, &nvmet_subsys_type);

        config_group_init_type_name(&subsys->namespaces_group,
                        "namespaces", &nvmet_namespaces_type);
        configfs_add_default_group(&subsys->namespaces_group, &subsys->group);

        config_group_init_type_name(&subsys->allowed_hosts_group,
                        "allowed_hosts", &nvmet_allowed_hosts_type);
        configfs_add_default_group(&subsys->allowed_hosts_group,
                        &subsys->group);

        nvmet_add_passthru_group(subsys);

        return &subsys->group;
}

static struct configfs_group_operations nvmet_subsystems_group_ops = {
        .make_group             = nvmet_subsys_make,
};

static const struct config_item_type nvmet_subsystems_type = {
        .ct_group_ops           = &nvmet_subsystems_group_ops,
        .ct_owner               = THIS_MODULE,
};

static ssize_t nvmet_referral_enable_show(struct config_item *item,
                char *page)
{
        return snprintf(page, PAGE_SIZE, "%d\n", to_nvmet_port(item)->enabled);
}

static ssize_t nvmet_referral_enable_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_port *parent = to_nvmet_port(item->ci_parent->ci_parent);
        struct nvmet_port *port = to_nvmet_port(item);
        bool enable;

        if (strtobool(page, &enable))
                goto inval;

        if (enable)
                nvmet_referral_enable(parent, port);
        else
                nvmet_referral_disable(parent, port);

        return count;
inval:
        pr_err("Invalid value '%s' for enable\n", page);
        return -EINVAL;
}

CONFIGFS_ATTR(nvmet_referral_, enable);

/*
 * Discovery Service subsystem definitions
 */
static struct configfs_attribute *nvmet_referral_attrs[] = {
        &nvmet_attr_addr_adrfam,
        &nvmet_attr_addr_portid,
        &nvmet_attr_addr_treq,
        &nvmet_attr_addr_traddr,
        &nvmet_attr_addr_trsvcid,
        &nvmet_attr_addr_trtype,
        &nvmet_referral_attr_enable,
        NULL,
};

static void nvmet_referral_notify(struct config_group *group,
                struct config_item *item)
{
        struct nvmet_port *parent = to_nvmet_port(item->ci_parent->ci_parent);
        struct nvmet_port *port = to_nvmet_port(item);

        nvmet_referral_disable(parent, port);
}

static void nvmet_referral_release(struct config_item *item)
{
        struct nvmet_port *port = to_nvmet_port(item);

        kfree(port);
}

static struct configfs_item_operations nvmet_referral_item_ops = {
        .release        = nvmet_referral_release,
};

static const struct config_item_type nvmet_referral_type = {
        .ct_owner       = THIS_MODULE,
        .ct_attrs       = nvmet_referral_attrs,
        .ct_item_ops    = &nvmet_referral_item_ops,
};

static struct config_group *nvmet_referral_make(
                struct config_group *group, const char *name)
{
        struct nvmet_port *port;

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

        INIT_LIST_HEAD(&port->entry);
        config_group_init_type_name(&port->group, name, &nvmet_referral_type);

        return &port->group;
}

static struct configfs_group_operations nvmet_referral_group_ops = {
        .make_group             = nvmet_referral_make,
        .disconnect_notify      = nvmet_referral_notify,
};

static const struct config_item_type nvmet_referrals_type = {
        .ct_owner       = THIS_MODULE,
        .ct_group_ops   = &nvmet_referral_group_ops,
};

static struct nvmet_type_name_map nvmet_ana_state[] = {
        { NVME_ANA_OPTIMIZED,           "optimized" },
        { NVME_ANA_NONOPTIMIZED,        "non-optimized" },
        { NVME_ANA_INACCESSIBLE,        "inaccessible" },
        { NVME_ANA_PERSISTENT_LOSS,     "persistent-loss" },
        { NVME_ANA_CHANGE,              "change" },
};

static ssize_t nvmet_ana_group_ana_state_show(struct config_item *item,
                char *page)
{
        struct nvmet_ana_group *grp = to_ana_group(item);
        enum nvme_ana_state state = grp->port->ana_state[grp->grpid];
        int i;

        for (i = 0; i < ARRAY_SIZE(nvmet_ana_state); i++) {
                if (state == nvmet_ana_state[i].type)
                        return sprintf(page, "%s\n", nvmet_ana_state[i].name);
        }

        return sprintf(page, "\n");
}

static ssize_t nvmet_ana_group_ana_state_store(struct config_item *item,
                const char *page, size_t count)
{
        struct nvmet_ana_group *grp = to_ana_group(item);
        enum nvme_ana_state *ana_state = grp->port->ana_state;
        int i;

        for (i = 0; i < ARRAY_SIZE(nvmet_ana_state); i++) {
                if (sysfs_streq(page, nvmet_ana_state[i].name))
                        goto found;
        }

        pr_err("Invalid value '%s' for ana_state\n", page);
        return -EINVAL;

found:
        down_write(&nvmet_ana_sem);
        ana_state[grp->grpid] = (enum nvme_ana_state) nvmet_ana_state[i].type;
        nvmet_ana_chgcnt++;
        up_write(&nvmet_ana_sem);
        nvmet_port_send_ana_event(grp->port);
        return count;
}

CONFIGFS_ATTR(nvmet_ana_group_, ana_state);

static struct configfs_attribute *nvmet_ana_group_attrs[] = {
        &nvmet_ana_group_attr_ana_state,
        NULL,
};

static void nvmet_ana_group_release(struct config_item *item)
{
        struct nvmet_ana_group *grp = to_ana_group(item);

        if (grp == &grp->port->ana_default_group)
                return;

        down_write(&nvmet_ana_sem);
        grp->port->ana_state[grp->grpid] = NVME_ANA_INACCESSIBLE;
        nvmet_ana_group_enabled[grp->grpid]--;
        up_write(&nvmet_ana_sem);

        nvmet_port_send_ana_event(grp->port);
        kfree(grp);
}

static struct configfs_item_operations nvmet_ana_group_item_ops = {
        .release                = nvmet_ana_group_release,
};

static const struct config_item_type nvmet_ana_group_type = {
        .ct_item_ops            = &nvmet_ana_group_item_ops,
        .ct_attrs               = nvmet_ana_group_attrs,
        .ct_owner               = THIS_MODULE,
};

static struct config_group *nvmet_ana_groups_make_group(
                struct config_group *group, const char *name)
{
        struct nvmet_port *port = ana_groups_to_port(&group->cg_item);
        struct nvmet_ana_group *grp;
        u32 grpid;
        int ret;

        ret = kstrtou32(name, 0, &grpid);
        if (ret)
                goto out;

        ret = -EINVAL;
        if (grpid <= 1 || grpid > NVMET_MAX_ANAGRPS)
                goto out;

        ret = -ENOMEM;
        grp = kzalloc(sizeof(*grp), GFP_KERNEL);
        if (!grp)
                goto out;
        grp->port = port;
        grp->grpid = grpid;

        down_write(&nvmet_ana_sem);
        nvmet_ana_group_enabled[grpid]++;
        up_write(&nvmet_ana_sem);

        nvmet_port_send_ana_event(grp->port);

        config_group_init_type_name(&grp->group, name, &nvmet_ana_group_type);
        return &grp->group;
out:
        return ERR_PTR(ret);
}

static struct configfs_group_operations nvmet_ana_groups_group_ops = {
        .make_group             = nvmet_ana_groups_make_group,
};

static const struct config_item_type nvmet_ana_groups_type = {
        .ct_group_ops           = &nvmet_ana_groups_group_ops,
        .ct_owner               = THIS_MODULE,
};

/*
 * Ports definitions.
 */
static void nvmet_port_release(struct config_item *item)
{
        struct nvmet_port *port = to_nvmet_port(item);

        list_del(&port->global_entry);

        kfree(port->ana_state);
        kfree(port);
}

static struct configfs_attribute *nvmet_port_attrs[] = {
        &nvmet_attr_addr_adrfam,
        &nvmet_attr_addr_treq,
        &nvmet_attr_addr_traddr,
        &nvmet_attr_addr_trsvcid,
        &nvmet_attr_addr_trtype,
        &nvmet_attr_param_inline_data_size,
#ifdef CONFIG_BLK_DEV_INTEGRITY
        &nvmet_attr_param_pi_enable,
#endif
        NULL,
};

static struct configfs_item_operations nvmet_port_item_ops = {
        .release                = nvmet_port_release,
};

static const struct config_item_type nvmet_port_type = {
        .ct_attrs               = nvmet_port_attrs,
        .ct_item_ops            = &nvmet_port_item_ops,
        .ct_owner               = THIS_MODULE,
};

static struct config_group *nvmet_ports_make(struct config_group *group,
                const char *name)
{
        struct nvmet_port *port;
        u16 portid;
        u32 i;

        if (kstrtou16(name, 0, &portid))
                return ERR_PTR(-EINVAL);

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

        port->ana_state = kcalloc(NVMET_MAX_ANAGRPS + 1,
                        sizeof(*port->ana_state), GFP_KERNEL);
        if (!port->ana_state) {
                kfree(port);
                return ERR_PTR(-ENOMEM);
        }

        for (i = 1; i <= NVMET_MAX_ANAGRPS; i++) {
                if (i == NVMET_DEFAULT_ANA_GRPID)
                        port->ana_state[1] = NVME_ANA_OPTIMIZED;
                else
                        port->ana_state[i] = NVME_ANA_INACCESSIBLE;
        }

        list_add(&port->global_entry, &nvmet_ports_list);

        INIT_LIST_HEAD(&port->entry);
        INIT_LIST_HEAD(&port->subsystems);
        INIT_LIST_HEAD(&port->referrals);
        port->inline_data_size = -1;    /* < 0 == let the transport choose */

        port->disc_addr.portid = cpu_to_le16(portid);
        port->disc_addr.adrfam = NVMF_ADDR_FAMILY_MAX;
        port->disc_addr.treq = NVMF_TREQ_DISABLE_SQFLOW;
        config_group_init_type_name(&port->group, name, &nvmet_port_type);

        config_group_init_type_name(&port->subsys_group,
                        "subsystems", &nvmet_port_subsys_type);
        configfs_add_default_group(&port->subsys_group, &port->group);

        config_group_init_type_name(&port->referrals_group,
                        "referrals", &nvmet_referrals_type);
        configfs_add_default_group(&port->referrals_group, &port->group);

        config_group_init_type_name(&port->ana_groups_group,
                        "ana_groups", &nvmet_ana_groups_type);
        configfs_add_default_group(&port->ana_groups_group, &port->group);

        port->ana_default_group.port = port;
        port->ana_default_group.grpid = NVMET_DEFAULT_ANA_GRPID;
        config_group_init_type_name(&port->ana_default_group.group,
                        __stringify(NVMET_DEFAULT_ANA_GRPID),
                        &nvmet_ana_group_type);
        configfs_add_default_group(&port->ana_default_group.group,
                        &port->ana_groups_group);

        return &port->group;
}

static struct configfs_group_operations nvmet_ports_group_ops = {
        .make_group             = nvmet_ports_make,
};

static const struct config_item_type nvmet_ports_type = {
        .ct_group_ops           = &nvmet_ports_group_ops,
        .ct_owner               = THIS_MODULE,
};

static struct config_group nvmet_subsystems_group;
static struct config_group nvmet_ports_group;

static void nvmet_host_release(struct config_item *item)
{
        struct nvmet_host *host = to_host(item);

        kfree(host);
}

static struct configfs_item_operations nvmet_host_item_ops = {
        .release                = nvmet_host_release,
};

static const struct config_item_type nvmet_host_type = {
        .ct_item_ops            = &nvmet_host_item_ops,
        .ct_owner               = THIS_MODULE,
};

static struct config_group *nvmet_hosts_make_group(struct config_group *group,
                const char *name)
{
        struct nvmet_host *host;

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

        config_group_init_type_name(&host->group, name, &nvmet_host_type);

        return &host->group;
}

static struct configfs_group_operations nvmet_hosts_group_ops = {
        .make_group             = nvmet_hosts_make_group,
};

static const struct config_item_type nvmet_hosts_type = {
        .ct_group_ops           = &nvmet_hosts_group_ops,
        .ct_owner               = THIS_MODULE,
};

static struct config_group nvmet_hosts_group;

static const struct config_item_type nvmet_root_type = {
        .ct_owner               = THIS_MODULE,
};

static struct configfs_subsystem nvmet_configfs_subsystem = {
        .su_group = {
                .cg_item = {
                        .ci_namebuf     = "nvmet",
                        .ci_type        = &nvmet_root_type,
                },
        },
};

int __init nvmet_init_configfs(void)
{
        int ret;

        config_group_init(&nvmet_configfs_subsystem.su_group);
        mutex_init(&nvmet_configfs_subsystem.su_mutex);

        config_group_init_type_name(&nvmet_subsystems_group,
                        "subsystems", &nvmet_subsystems_type);
        configfs_add_default_group(&nvmet_subsystems_group,
                        &nvmet_configfs_subsystem.su_group);

        config_group_init_type_name(&nvmet_ports_group,
                        "ports", &nvmet_ports_type);
        configfs_add_default_group(&nvmet_ports_group,
                        &nvmet_configfs_subsystem.su_group);

        config_group_init_type_name(&nvmet_hosts_group,
                        "hosts", &nvmet_hosts_type);
        configfs_add_default_group(&nvmet_hosts_group,
                        &nvmet_configfs_subsystem.su_group);

        ret = configfs_register_subsystem(&nvmet_configfs_subsystem);
        if (ret) {
                pr_err("configfs_register_subsystem: %d\n", ret);
                return ret;
        }

        return 0;
}

void __exit nvmet_exit_configfs(void)
{
        configfs_unregister_subsystem(&nvmet_configfs_subsystem);
}