// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2004, 2005 Oracle.  All rights reserved.
 */

#include <linux/slab.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/configfs.h>

#include "tcp.h"
#include "nodemanager.h"
#include "heartbeat.h"
#include "masklog.h"
#include "sys.h"

/* for now we operate under the assertion that there can be only one
 * cluster active at a time.  Changing this will require trickling
 * cluster references throughout where nodes are looked up */
struct o2nm_cluster *o2nm_single_cluster = NULL;

static const char *o2nm_fence_method_desc[O2NM_FENCE_METHODS] = {
        "reset",        /* O2NM_FENCE_RESET */
        "panic",        /* O2NM_FENCE_PANIC */
};

static inline void o2nm_lock_subsystem(void);
static inline void o2nm_unlock_subsystem(void);

struct o2nm_node *o2nm_get_node_by_num(u8 node_num)
{
        struct o2nm_node *node = NULL;

        if (node_num >= O2NM_MAX_NODES || o2nm_single_cluster == NULL)
                goto out;

        read_lock(&o2nm_single_cluster->cl_nodes_lock);
        node = o2nm_single_cluster->cl_nodes[node_num];
        if (node)
                config_item_get(&node->nd_item);
        read_unlock(&o2nm_single_cluster->cl_nodes_lock);
out:
        return node;
}
EXPORT_SYMBOL_GPL(o2nm_get_node_by_num);

int o2nm_configured_node_map(unsigned long *map, unsigned bytes)
{
        struct o2nm_cluster *cluster = o2nm_single_cluster;

        BUG_ON(bytes < (sizeof(cluster->cl_nodes_bitmap)));

        if (cluster == NULL)
                return -EINVAL;

        read_lock(&cluster->cl_nodes_lock);
        bitmap_copy(map, cluster->cl_nodes_bitmap, O2NM_MAX_NODES);
        read_unlock(&cluster->cl_nodes_lock);

        return 0;
}
EXPORT_SYMBOL_GPL(o2nm_configured_node_map);

static struct o2nm_node *o2nm_node_ip_tree_lookup(struct o2nm_cluster *cluster,
                                                  __be32 ip_needle,
                                                  struct rb_node ***ret_p,
                                                  struct rb_node **ret_parent)
{
        struct rb_node **p = &cluster->cl_node_ip_tree.rb_node;
        struct rb_node *parent = NULL;
        struct o2nm_node *node, *ret = NULL;

        while (*p) {
                int cmp;

                parent = *p;
                node = rb_entry(parent, struct o2nm_node, nd_ip_node);

                cmp = memcmp(&ip_needle, &node->nd_ipv4_address,
                                sizeof(ip_needle));
                if (cmp < 0)
                        p = &(*p)->rb_left;
                else if (cmp > 0)
                        p = &(*p)->rb_right;
                else {
                        ret = node;
                        break;
                }
        }

        if (ret_p != NULL)
                *ret_p = p;
        if (ret_parent != NULL)
                *ret_parent = parent;

        return ret;
}

struct o2nm_node *o2nm_get_node_by_ip(__be32 addr)
{
        struct o2nm_node *node = NULL;
        struct o2nm_cluster *cluster = o2nm_single_cluster;

        if (cluster == NULL)
                goto out;

        read_lock(&cluster->cl_nodes_lock);
        node = o2nm_node_ip_tree_lookup(cluster, addr, NULL, NULL);
        if (node)
                config_item_get(&node->nd_item);
        read_unlock(&cluster->cl_nodes_lock);

out:
        return node;
}
EXPORT_SYMBOL_GPL(o2nm_get_node_by_ip);

void o2nm_node_put(struct o2nm_node *node)
{
        config_item_put(&node->nd_item);
}
EXPORT_SYMBOL_GPL(o2nm_node_put);

void o2nm_node_get(struct o2nm_node *node)
{
        config_item_get(&node->nd_item);
}
EXPORT_SYMBOL_GPL(o2nm_node_get);

u8 o2nm_this_node(void)
{
        u8 node_num = O2NM_MAX_NODES;

        if (o2nm_single_cluster && o2nm_single_cluster->cl_has_local)
                node_num = o2nm_single_cluster->cl_local_node;

        return node_num;
}
EXPORT_SYMBOL_GPL(o2nm_this_node);

/* node configfs bits */

static struct o2nm_cluster *to_o2nm_cluster(struct config_item *item)
{
        return item ?
                container_of(to_config_group(item), struct o2nm_cluster,
                             cl_group)
                : NULL;
}

static struct o2nm_node *to_o2nm_node(struct config_item *item)
{
        return item ? container_of(item, struct o2nm_node, nd_item) : NULL;
}

static void o2nm_node_release(struct config_item *item)
{
        struct o2nm_node *node = to_o2nm_node(item);
        kfree(node);
}

static ssize_t o2nm_node_num_show(struct config_item *item, char *page)
{
        return sprintf(page, "%d\n", to_o2nm_node(item)->nd_num);
}

static struct o2nm_cluster *to_o2nm_cluster_from_node(struct o2nm_node *node)
{
        /* through the first node_set .parent
         * mycluster/nodes/mynode == o2nm_cluster->o2nm_node_group->o2nm_node */
        if (node->nd_item.ci_parent)
                return to_o2nm_cluster(node->nd_item.ci_parent->ci_parent);
        else
                return NULL;
}

enum {
        O2NM_NODE_ATTR_NUM = 0,
        O2NM_NODE_ATTR_PORT,
        O2NM_NODE_ATTR_ADDRESS,
};

static ssize_t o2nm_node_num_store(struct config_item *item, const char *page,
                                   size_t count)
{
        struct o2nm_node *node = to_o2nm_node(item);
        struct o2nm_cluster *cluster;
        unsigned long tmp;
        char *p = (char *)page;
        int ret = 0;

        tmp = simple_strtoul(p, &p, 0);
        if (!p || (*p && (*p != '\n')))
                return -EINVAL;

        if (tmp >= O2NM_MAX_NODES)
                return -ERANGE;

        /* once we're in the cl_nodes tree networking can look us up by
         * node number and try to use our address and port attributes
         * to connect to this node.. make sure that they've been set
         * before writing the node attribute? */
        if (!test_bit(O2NM_NODE_ATTR_ADDRESS, &node->nd_set_attributes) ||
            !test_bit(O2NM_NODE_ATTR_PORT, &node->nd_set_attributes))
                return -EINVAL; /* XXX */

        o2nm_lock_subsystem();
        cluster = to_o2nm_cluster_from_node(node);
        if (!cluster) {
                o2nm_unlock_subsystem();
                return -EINVAL;
        }

        write_lock(&cluster->cl_nodes_lock);
        if (cluster->cl_nodes[tmp])
                ret = -EEXIST;
        else if (test_and_set_bit(O2NM_NODE_ATTR_NUM,
                        &node->nd_set_attributes))
                ret = -EBUSY;
        else  {
                cluster->cl_nodes[tmp] = node;
                node->nd_num = tmp;
                set_bit(tmp, cluster->cl_nodes_bitmap);
        }
        write_unlock(&cluster->cl_nodes_lock);
        o2nm_unlock_subsystem();

        if (ret)
                return ret;

        return count;
}
static ssize_t o2nm_node_ipv4_port_show(struct config_item *item, char *page)
{
        return sprintf(page, "%u\n", ntohs(to_o2nm_node(item)->nd_ipv4_port));
}

static ssize_t o2nm_node_ipv4_port_store(struct config_item *item,
                                         const char *page, size_t count)
{
        struct o2nm_node *node = to_o2nm_node(item);
        unsigned long tmp;
        char *p = (char *)page;

        tmp = simple_strtoul(p, &p, 0);
        if (!p || (*p && (*p != '\n')))
                return -EINVAL;

        if (tmp == 0)
                return -EINVAL;
        if (tmp >= (u16)-1)
                return -ERANGE;

        if (test_and_set_bit(O2NM_NODE_ATTR_PORT, &node->nd_set_attributes))
                return -EBUSY;
        node->nd_ipv4_port = htons(tmp);

        return count;
}

static ssize_t o2nm_node_ipv4_address_show(struct config_item *item, char *page)
{
        return sprintf(page, "%pI4\n", &to_o2nm_node(item)->nd_ipv4_address);
}

static ssize_t o2nm_node_ipv4_address_store(struct config_item *item,
                                            const char *page,
                                            size_t count)
{
        struct o2nm_node *node = to_o2nm_node(item);
        struct o2nm_cluster *cluster;
        int ret, i;
        struct rb_node **p, *parent;
        unsigned int octets[4];
        __be32 ipv4_addr = 0;

        ret = sscanf(page, "%3u.%3u.%3u.%3u", &octets[3], &octets[2],
                     &octets[1], &octets[0]);
        if (ret != 4)
                return -EINVAL;

        for (i = 0; i < ARRAY_SIZE(octets); i++) {
                if (octets[i] > 255)
                        return -ERANGE;
                be32_add_cpu(&ipv4_addr, octets[i] << (i * 8));
        }

        o2nm_lock_subsystem();
        cluster = to_o2nm_cluster_from_node(node);
        if (!cluster) {
                o2nm_unlock_subsystem();
                return -EINVAL;
        }

        ret = 0;
        write_lock(&cluster->cl_nodes_lock);
        if (o2nm_node_ip_tree_lookup(cluster, ipv4_addr, &p, &parent))
                ret = -EEXIST;
        else if (test_and_set_bit(O2NM_NODE_ATTR_ADDRESS,
                        &node->nd_set_attributes))
                ret = -EBUSY;
        else {
                rb_link_node(&node->nd_ip_node, parent, p);
                rb_insert_color(&node->nd_ip_node, &cluster->cl_node_ip_tree);
        }
        write_unlock(&cluster->cl_nodes_lock);
        o2nm_unlock_subsystem();

        if (ret)
                return ret;

        memcpy(&node->nd_ipv4_address, &ipv4_addr, sizeof(ipv4_addr));

        return count;
}

static ssize_t o2nm_node_local_show(struct config_item *item, char *page)
{
        return sprintf(page, "%d\n", to_o2nm_node(item)->nd_local);
}

static ssize_t o2nm_node_local_store(struct config_item *item, const char *page,
                                     size_t count)
{
        struct o2nm_node *node = to_o2nm_node(item);
        struct o2nm_cluster *cluster;
        unsigned long tmp;
        char *p = (char *)page;
        ssize_t ret;

        tmp = simple_strtoul(p, &p, 0);
        if (!p || (*p && (*p != '\n')))
                return -EINVAL;

        tmp = !!tmp; /* boolean of whether this node wants to be local */

        /* setting local turns on networking rx for now so we require having
         * set everything else first */
        if (!test_bit(O2NM_NODE_ATTR_ADDRESS, &node->nd_set_attributes) ||
            !test_bit(O2NM_NODE_ATTR_NUM, &node->nd_set_attributes) ||
            !test_bit(O2NM_NODE_ATTR_PORT, &node->nd_set_attributes))
                return -EINVAL; /* XXX */

        o2nm_lock_subsystem();
        cluster = to_o2nm_cluster_from_node(node);
        if (!cluster) {
                ret = -EINVAL;
                goto out;
        }

        /* the only failure case is trying to set a new local node
         * when a different one is already set */
        if (tmp && tmp == cluster->cl_has_local &&
            cluster->cl_local_node != node->nd_num) {
                ret = -EBUSY;
                goto out;
        }

        /* bring up the rx thread if we're setting the new local node. */
        if (tmp && !cluster->cl_has_local) {
                ret = o2net_start_listening(node);
                if (ret)
                        goto out;
        }

        if (!tmp && cluster->cl_has_local &&
            cluster->cl_local_node == node->nd_num) {
                o2net_stop_listening(node);
                cluster->cl_local_node = O2NM_INVALID_NODE_NUM;
        }

        node->nd_local = tmp;
        if (node->nd_local) {
                cluster->cl_has_local = tmp;
                cluster->cl_local_node = node->nd_num;
        }

        ret = count;

out:
        o2nm_unlock_subsystem();
        return ret;
}

CONFIGFS_ATTR(o2nm_node_, num);
CONFIGFS_ATTR(o2nm_node_, ipv4_port);
CONFIGFS_ATTR(o2nm_node_, ipv4_address);
CONFIGFS_ATTR(o2nm_node_, local);

static struct configfs_attribute *o2nm_node_attrs[] = {
        &o2nm_node_attr_num,
        &o2nm_node_attr_ipv4_port,
        &o2nm_node_attr_ipv4_address,
        &o2nm_node_attr_local,
        NULL,
};

static const struct configfs_item_operations o2nm_node_item_ops = {
        .release                = o2nm_node_release,
};

static const struct config_item_type o2nm_node_type = {
        .ct_item_ops    = &o2nm_node_item_ops,
        .ct_attrs       = o2nm_node_attrs,
        .ct_owner       = THIS_MODULE,
};

/* node set */

struct o2nm_node_group {
        struct config_group ns_group;
        /* some stuff? */
};

#if 0
static struct o2nm_node_group *to_o2nm_node_group(struct config_group *group)
{
        return group ?
                container_of(group, struct o2nm_node_group, ns_group)
                : NULL;
}
#endif

static ssize_t o2nm_cluster_attr_write(const char *page, ssize_t count,
                                       unsigned int *val)
{
        unsigned long tmp;
        char *p = (char *)page;

        tmp = simple_strtoul(p, &p, 0);
        if (!p || (*p && (*p != '\n')))
                return -EINVAL;

        if (tmp == 0)
                return -EINVAL;
        if (tmp >= (u32)-1)
                return -ERANGE;

        *val = tmp;

        return count;
}

static ssize_t o2nm_cluster_idle_timeout_ms_show(struct config_item *item,
        char *page)
{
        return sprintf(page, "%u\n", to_o2nm_cluster(item)->cl_idle_timeout_ms);
}

static ssize_t o2nm_cluster_idle_timeout_ms_store(struct config_item *item,
        const char *page, size_t count)
{
        struct o2nm_cluster *cluster = to_o2nm_cluster(item);
        ssize_t ret;
        unsigned int val;

        ret =  o2nm_cluster_attr_write(page, count, &val);

        if (ret > 0) {
                if (cluster->cl_idle_timeout_ms != val
                        && o2net_num_connected_peers()) {
                        mlog(ML_NOTICE,
                             "o2net: cannot change idle timeout after "
                             "the first peer has agreed to it."
                             "  %d connected peers\n",
                             o2net_num_connected_peers());
                        ret = -EINVAL;
                } else if (val <= cluster->cl_keepalive_delay_ms) {
                        mlog(ML_NOTICE, "o2net: idle timeout must be larger "
                             "than keepalive delay\n");
                        ret = -EINVAL;
                } else {
                        cluster->cl_idle_timeout_ms = val;
                }
        }

        return ret;
}

static ssize_t o2nm_cluster_keepalive_delay_ms_show(
        struct config_item *item, char *page)
{
        return sprintf(page, "%u\n",
                        to_o2nm_cluster(item)->cl_keepalive_delay_ms);
}

static ssize_t o2nm_cluster_keepalive_delay_ms_store(
        struct config_item *item, const char *page, size_t count)
{
        struct o2nm_cluster *cluster = to_o2nm_cluster(item);
        ssize_t ret;
        unsigned int val;

        ret =  o2nm_cluster_attr_write(page, count, &val);

        if (ret > 0) {
                if (cluster->cl_keepalive_delay_ms != val
                    && o2net_num_connected_peers()) {
                        mlog(ML_NOTICE,
                             "o2net: cannot change keepalive delay after"
                             " the first peer has agreed to it."
                             "  %d connected peers\n",
                             o2net_num_connected_peers());
                        ret = -EINVAL;
                } else if (val >= cluster->cl_idle_timeout_ms) {
                        mlog(ML_NOTICE, "o2net: keepalive delay must be "
                             "smaller than idle timeout\n");
                        ret = -EINVAL;
                } else {
                        cluster->cl_keepalive_delay_ms = val;
                }
        }

        return ret;
}

static ssize_t o2nm_cluster_reconnect_delay_ms_show(
        struct config_item *item, char *page)
{
        return sprintf(page, "%u\n",
                        to_o2nm_cluster(item)->cl_reconnect_delay_ms);
}

static ssize_t o2nm_cluster_reconnect_delay_ms_store(
        struct config_item *item, const char *page, size_t count)
{
        return o2nm_cluster_attr_write(page, count,
                               &to_o2nm_cluster(item)->cl_reconnect_delay_ms);
}

static ssize_t o2nm_cluster_fence_method_show(
        struct config_item *item, char *page)
{
        struct o2nm_cluster *cluster = to_o2nm_cluster(item);
        ssize_t ret = 0;

        if (cluster)
                ret = sprintf(page, "%s\n",
                              o2nm_fence_method_desc[cluster->cl_fence_method]);
        return ret;
}

static ssize_t o2nm_cluster_fence_method_store(
        struct config_item *item, const char *page, size_t count)
{
        unsigned int i;

        if (page[count - 1] != '\n')
                goto bail;

        for (i = 0; i < O2NM_FENCE_METHODS; ++i) {
                if (count != strlen(o2nm_fence_method_desc[i]) + 1)
                        continue;
                if (strncasecmp(page, o2nm_fence_method_desc[i], count - 1))
                        continue;
                if (to_o2nm_cluster(item)->cl_fence_method != i) {
                        printk(KERN_INFO "ocfs2: Changing fence method to %s\n",
                               o2nm_fence_method_desc[i]);
                        to_o2nm_cluster(item)->cl_fence_method = i;
                }
                return count;
        }

bail:
        return -EINVAL;
}

CONFIGFS_ATTR(o2nm_cluster_, idle_timeout_ms);
CONFIGFS_ATTR(o2nm_cluster_, keepalive_delay_ms);
CONFIGFS_ATTR(o2nm_cluster_, reconnect_delay_ms);
CONFIGFS_ATTR(o2nm_cluster_, fence_method);

static struct configfs_attribute *o2nm_cluster_attrs[] = {
        &o2nm_cluster_attr_idle_timeout_ms,
        &o2nm_cluster_attr_keepalive_delay_ms,
        &o2nm_cluster_attr_reconnect_delay_ms,
        &o2nm_cluster_attr_fence_method,
        NULL,
};

static struct config_item *o2nm_node_group_make_item(struct config_group *group,
                                                     const char *name)
{
        struct o2nm_node *node = NULL;

        if (strlen(name) > O2NM_MAX_NAME_LEN)
                return ERR_PTR(-ENAMETOOLONG);

        node = kzalloc_obj(struct o2nm_node);
        if (node == NULL)
                return ERR_PTR(-ENOMEM);

        strscpy(node->nd_name, name); /* use item.ci_namebuf instead? */
        config_item_init_type_name(&node->nd_item, name, &o2nm_node_type);
        spin_lock_init(&node->nd_lock);

        mlog(ML_CLUSTER, "o2nm: Registering node %s\n", name);

        return &node->nd_item;
}

static void o2nm_node_group_drop_item(struct config_group *group,
                                      struct config_item *item)
{
        struct o2nm_node *node = to_o2nm_node(item);
        struct o2nm_cluster *cluster = to_o2nm_cluster(group->cg_item.ci_parent);

        if (cluster->cl_nodes[node->nd_num] == node) {
                o2net_disconnect_node(node);

                if (cluster->cl_has_local &&
                    (cluster->cl_local_node == node->nd_num)) {
                        cluster->cl_has_local = 0;
                        cluster->cl_local_node = O2NM_INVALID_NODE_NUM;
                        o2net_stop_listening(node);
                }
        }

        /* XXX call into net to stop this node from trading messages */

        write_lock(&cluster->cl_nodes_lock);

        /* XXX sloppy */
        if (node->nd_ipv4_address)
                rb_erase(&node->nd_ip_node, &cluster->cl_node_ip_tree);

        /* nd_num might be 0 if the node number hasn't been set.. */
        if (cluster->cl_nodes[node->nd_num] == node) {
                cluster->cl_nodes[node->nd_num] = NULL;
                clear_bit(node->nd_num, cluster->cl_nodes_bitmap);
        }
        write_unlock(&cluster->cl_nodes_lock);

        mlog(ML_CLUSTER, "o2nm: Unregistered node %s\n",
             config_item_name(&node->nd_item));

        config_item_put(item);
}

static const struct configfs_group_operations o2nm_node_group_group_ops = {
        .make_item      = o2nm_node_group_make_item,
        .drop_item      = o2nm_node_group_drop_item,
};

static const struct config_item_type o2nm_node_group_type = {
        .ct_group_ops   = &o2nm_node_group_group_ops,
        .ct_owner       = THIS_MODULE,
};

/* cluster */

static void o2nm_cluster_release(struct config_item *item)
{
        struct o2nm_cluster *cluster = to_o2nm_cluster(item);

        kfree(cluster);
}

static const struct configfs_item_operations o2nm_cluster_item_ops = {
        .release        = o2nm_cluster_release,
};

static const struct config_item_type o2nm_cluster_type = {
        .ct_item_ops    = &o2nm_cluster_item_ops,
        .ct_attrs       = o2nm_cluster_attrs,
        .ct_owner       = THIS_MODULE,
};

/* cluster set */

struct o2nm_cluster_group {
        struct configfs_subsystem cs_subsys;
        /* some stuff? */
};

#if 0
static struct o2nm_cluster_group *to_o2nm_cluster_group(struct config_group *group)
{
        return group ?
                container_of(to_configfs_subsystem(group), struct o2nm_cluster_group, cs_subsys)
               : NULL;
}
#endif

static struct config_group *o2nm_cluster_group_make_group(struct config_group *group,
                                                          const char *name)
{
        struct o2nm_cluster *cluster = NULL;
        struct o2nm_node_group *ns = NULL;
        struct config_group *o2hb_group = NULL, *ret = NULL;

        /* this runs under the parent dir's i_rwsem; there can be only
         * one caller in here at a time */
        if (o2nm_single_cluster)
                return ERR_PTR(-ENOSPC);

        cluster = kzalloc_obj(struct o2nm_cluster);
        ns = kzalloc_obj(struct o2nm_node_group);
        o2hb_group = o2hb_alloc_hb_set();
        if (cluster == NULL || ns == NULL || o2hb_group == NULL)
                goto out;

        config_group_init_type_name(&cluster->cl_group, name,
                                    &o2nm_cluster_type);
        configfs_add_default_group(&ns->ns_group, &cluster->cl_group);

        config_group_init_type_name(&ns->ns_group, "node",
                                    &o2nm_node_group_type);
        configfs_add_default_group(o2hb_group, &cluster->cl_group);

        rwlock_init(&cluster->cl_nodes_lock);
        cluster->cl_node_ip_tree = RB_ROOT;
        cluster->cl_reconnect_delay_ms = O2NET_RECONNECT_DELAY_MS_DEFAULT;
        cluster->cl_idle_timeout_ms    = O2NET_IDLE_TIMEOUT_MS_DEFAULT;
        cluster->cl_keepalive_delay_ms = O2NET_KEEPALIVE_DELAY_MS_DEFAULT;
        cluster->cl_fence_method       = O2NM_FENCE_RESET;

        ret = &cluster->cl_group;
        o2nm_single_cluster = cluster;

out:
        if (ret == NULL) {
                kfree(cluster);
                kfree(ns);
                o2hb_free_hb_set(o2hb_group);
                ret = ERR_PTR(-ENOMEM);
        }

        return ret;
}

static void o2nm_cluster_group_drop_item(struct config_group *group, struct config_item *item)
{
        struct o2nm_cluster *cluster = to_o2nm_cluster(item);

        BUG_ON(o2nm_single_cluster != cluster);
        o2nm_single_cluster = NULL;

        configfs_remove_default_groups(&cluster->cl_group);
        config_item_put(item);
}

static const struct configfs_group_operations o2nm_cluster_group_group_ops = {
        .make_group     = o2nm_cluster_group_make_group,
        .drop_item      = o2nm_cluster_group_drop_item,
};

static const struct config_item_type o2nm_cluster_group_type = {
        .ct_group_ops   = &o2nm_cluster_group_group_ops,
        .ct_owner       = THIS_MODULE,
};

static struct o2nm_cluster_group o2nm_cluster_group = {
        .cs_subsys = {
                .su_group = {
                        .cg_item = {
                                .ci_namebuf = "cluster",
                                .ci_type = &o2nm_cluster_group_type,
                        },
                },
        },
};

static inline void o2nm_lock_subsystem(void)
{
        mutex_lock(&o2nm_cluster_group.cs_subsys.su_mutex);
}

static inline void o2nm_unlock_subsystem(void)
{
        mutex_unlock(&o2nm_cluster_group.cs_subsys.su_mutex);
}

int o2nm_depend_item(struct config_item *item)
{
        return configfs_depend_item(&o2nm_cluster_group.cs_subsys, item);
}

void o2nm_undepend_item(struct config_item *item)
{
        configfs_undepend_item(item);
}

int o2nm_depend_this_node(void)
{
        int ret = 0;
        struct o2nm_node *local_node;

        local_node = o2nm_get_node_by_num(o2nm_this_node());
        if (!local_node) {
                ret = -EINVAL;
                goto out;
        }

        ret = o2nm_depend_item(&local_node->nd_item);
        o2nm_node_put(local_node);

out:
        return ret;
}

void o2nm_undepend_this_node(void)
{
        struct o2nm_node *local_node;

        local_node = o2nm_get_node_by_num(o2nm_this_node());
        BUG_ON(!local_node);

        o2nm_undepend_item(&local_node->nd_item);
        o2nm_node_put(local_node);
}


static void __exit exit_o2nm(void)
{
        /* XXX sync with hb callbacks and shut down hb? */
        o2net_unregister_hb_callbacks();
        configfs_unregister_subsystem(&o2nm_cluster_group.cs_subsys);
        o2cb_sys_shutdown();

        o2net_exit();
        o2hb_exit();
}

static int __init init_o2nm(void)
{
        int ret;

        o2hb_init();

        ret = o2net_init();
        if (ret)
                goto out_o2hb;

        ret = o2net_register_hb_callbacks();
        if (ret)
                goto out_o2net;

        config_group_init(&o2nm_cluster_group.cs_subsys.su_group);
        mutex_init(&o2nm_cluster_group.cs_subsys.su_mutex);
        ret = configfs_register_subsystem(&o2nm_cluster_group.cs_subsys);
        if (ret) {
                printk(KERN_ERR "nodemanager: Registration returned %d\n", ret);
                goto out_callbacks;
        }

        ret = o2cb_sys_init();
        if (!ret)
                goto out;

        configfs_unregister_subsystem(&o2nm_cluster_group.cs_subsys);
out_callbacks:
        o2net_unregister_hb_callbacks();
out_o2net:
        o2net_exit();
out_o2hb:
        o2hb_exit();
out:
        return ret;
}

MODULE_AUTHOR("Oracle");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("OCFS2 cluster management");

module_init(init_o2nm)
module_exit(exit_o2nm)