v4.19.13 snapshot.
diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
new file mode 100644
index 0000000..b37a8e3
--- /dev/null
+++ b/drivers/nvme/target/configfs.c
@@ -0,0 +1,1276 @@
+/*
+ * Configfs interface for the NVMe target.
+ * Copyright (c) 2015-2016 HGST, a Western Digital Company.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+#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 "nvmet.h"
+
+static const struct config_item_type nvmet_host_type;
+static const struct config_item_type nvmet_subsys_type;
+
+static const struct nvmet_transport_name {
+	u8		type;
+	const char	*name;
+} nvmet_transport_names[] = {
+	{ NVMF_TRTYPE_RDMA,	"rdma" },
+	{ NVMF_TRTYPE_FC,	"fc" },
+	{ NVMF_TRTYPE_LOOP,	"loop" },
+};
+
+/*
+ * 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)
+{
+	switch (to_nvmet_port(item)->disc_addr.adrfam) {
+	case NVMF_ADDR_FAMILY_IP4:
+		return sprintf(page, "ipv4\n");
+	case NVMF_ADDR_FAMILY_IP6:
+		return sprintf(page, "ipv6\n");
+	case NVMF_ADDR_FAMILY_IB:
+		return sprintf(page, "ib\n");
+	case NVMF_ADDR_FAMILY_FC:
+		return sprintf(page, "fc\n");
+	default:
+		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);
+
+	if (port->enabled) {
+		pr_err("Cannot modify address while enabled\n");
+		pr_err("Disable the address before modifying\n");
+		return -EACCES;
+	}
+
+	if (sysfs_streq(page, "ipv4")) {
+		port->disc_addr.adrfam = NVMF_ADDR_FAMILY_IP4;
+	} else if (sysfs_streq(page, "ipv6")) {
+		port->disc_addr.adrfam = NVMF_ADDR_FAMILY_IP6;
+	} else if (sysfs_streq(page, "ib")) {
+		port->disc_addr.adrfam = NVMF_ADDR_FAMILY_IB;
+	} else if (sysfs_streq(page, "fc")) {
+		port->disc_addr.adrfam = NVMF_ADDR_FAMILY_FC;
+	} else {
+		pr_err("Invalid value '%s' for adrfam\n", page);
+		return -EINVAL;
+	}
+
+	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 (port->enabled) {
+		pr_err("Cannot modify address while enabled\n");
+		pr_err("Disable the address before modifying\n");
+		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 (port->enabled) {
+		pr_err("Cannot modify address while enabled\n");
+		pr_err("Disable the address before modifying\n");
+		return -EACCES;
+	}
+
+	if (sscanf(page, "%s\n", port->disc_addr.traddr) != 1)
+		return -EINVAL;
+	return count;
+}
+
+CONFIGFS_ATTR(nvmet_, addr_traddr);
+
+static ssize_t nvmet_addr_treq_show(struct config_item *item,
+		char *page)
+{
+	switch (to_nvmet_port(item)->disc_addr.treq) {
+	case NVMF_TREQ_NOT_SPECIFIED:
+		return sprintf(page, "not specified\n");
+	case NVMF_TREQ_REQUIRED:
+		return sprintf(page, "required\n");
+	case NVMF_TREQ_NOT_REQUIRED:
+		return sprintf(page, "not required\n");
+	default:
+		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);
+
+	if (port->enabled) {
+		pr_err("Cannot modify address while enabled\n");
+		pr_err("Disable the address before modifying\n");
+		return -EACCES;
+	}
+
+	if (sysfs_streq(page, "not specified")) {
+		port->disc_addr.treq = NVMF_TREQ_NOT_SPECIFIED;
+	} else if (sysfs_streq(page, "required")) {
+		port->disc_addr.treq = NVMF_TREQ_REQUIRED;
+	} else if (sysfs_streq(page, "not required")) {
+		port->disc_addr.treq = NVMF_TREQ_NOT_REQUIRED;
+	} else {
+		pr_err("Invalid value '%s' for treq\n", page);
+		return -EINVAL;
+	}
+
+	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 (port->enabled) {
+		pr_err("Cannot modify address while enabled\n");
+		pr_err("Disable the address before modifying\n");
+		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 (port->enabled) {
+		pr_err("Cannot modify inline_data_size while port enabled\n");
+		pr_err("Disable the port before modifying\n");
+		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);
+
+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_names); i++) {
+		if (port->disc_addr.trtype != nvmet_transport_names[i].type)
+			continue;
+		return sprintf(page, "%s\n", nvmet_transport_names[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 (port->enabled) {
+		pr_err("Cannot modify address while enabled\n");
+		pr_err("Disable the address before modifying\n");
+		return -EACCES;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(nvmet_transport_names); i++) {
+		if (sysfs_streq(page, nvmet_transport_names[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_names[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 = kstrndup(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);
+
+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 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,
+	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)
+		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,
+};
+
+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_genctr++;
+	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_genctr++;
+	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_genctr++;
+	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_genctr++;
+	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;
+	}
+
+	subsys->allow_any_host = allow_any_host;
+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, "%d.%d.%d\n",
+				(int)NVME_MAJOR(subsys->ver),
+				(int)NVME_MINOR(subsys->ver),
+				(int)NVME_TERTIARY(subsys->ver));
+	else
+		return snprintf(page, PAGE_SIZE, "%d.%d\n",
+				(int)NVME_MAJOR(subsys->ver),
+				(int)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;
+
+
+	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)
+{
+	struct nvmet_subsys *subsys = to_subsys(item);
+
+	down_write(&nvmet_config_sem);
+	sscanf(page, "%llx\n", &subsys->serial);
+	up_write(&nvmet_config_sem);
+
+	return count;
+}
+CONFIGFS_ATTR(nvmet_subsys_, attr_serial);
+
+static struct configfs_attribute *nvmet_subsys_attrs[] = {
+	&nvmet_subsys_attr_attr_allow_any_host,
+	&nvmet_subsys_attr_attr_version,
+	&nvmet_subsys_attr_attr_serial,
+	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 (!subsys)
+		return ERR_PTR(-ENOMEM);
+
+	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);
+
+	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(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_release(struct config_item *item)
+{
+	struct nvmet_port *port = to_nvmet_port(item);
+
+	nvmet_referral_disable(port);
+	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,
+};
+
+static const struct config_item_type nvmet_referrals_type = {
+	.ct_owner	= THIS_MODULE,
+	.ct_group_ops	= &nvmet_referral_group_ops,
+};
+
+static struct {
+	enum nvme_ana_state	state;
+	const char		*name;
+} nvmet_ana_state_names[] = {
+	{ 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_names); i++) {
+		if (state != nvmet_ana_state_names[i].state)
+			continue;
+		return sprintf(page, "%s\n", nvmet_ana_state_names[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);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(nvmet_ana_state_names); i++) {
+		if (sysfs_streq(page, nvmet_ana_state_names[i].name))
+			goto found;
+	}
+
+	pr_err("Invalid value '%s' for ana_state\n", page);
+	return -EINVAL;
+
+found:
+	down_write(&nvmet_ana_sem);
+	grp->port->ana_state[grp->grpid] = nvmet_ana_state_names[i].state;
+	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);
+
+	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,
+	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;
+	}
+
+	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);
+	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);
+}