blob: 7139e67e93aebf7f9b5435f4fc672d35f4331967 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2016 Mellanox Technologies. All rights reserved.
* Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
*/
#include "devl_internal.h"
static inline bool
devlink_rate_is_leaf(struct devlink_rate *devlink_rate)
{
return devlink_rate->type == DEVLINK_RATE_TYPE_LEAF;
}
static inline bool
devlink_rate_is_node(struct devlink_rate *devlink_rate)
{
return devlink_rate->type == DEVLINK_RATE_TYPE_NODE;
}
static struct devlink_rate *
devlink_rate_leaf_get_from_info(struct devlink *devlink, struct genl_info *info)
{
struct devlink_rate *devlink_rate;
struct devlink_port *devlink_port;
devlink_port = devlink_port_get_from_attrs(devlink, info->attrs);
if (IS_ERR(devlink_port))
return ERR_CAST(devlink_port);
devlink_rate = devlink_port->devlink_rate;
return devlink_rate ?: ERR_PTR(-ENODEV);
}
static struct devlink_rate *
devlink_rate_node_get_by_name(struct devlink *devlink, const char *node_name)
{
static struct devlink_rate *devlink_rate;
list_for_each_entry(devlink_rate, &devlink->rate_list, list) {
if (devlink_rate_is_node(devlink_rate) &&
!strcmp(node_name, devlink_rate->name))
return devlink_rate;
}
return ERR_PTR(-ENODEV);
}
static struct devlink_rate *
devlink_rate_node_get_from_attrs(struct devlink *devlink, struct nlattr **attrs)
{
const char *rate_node_name;
size_t len;
if (!attrs[DEVLINK_ATTR_RATE_NODE_NAME])
return ERR_PTR(-EINVAL);
rate_node_name = nla_data(attrs[DEVLINK_ATTR_RATE_NODE_NAME]);
len = strlen(rate_node_name);
/* Name cannot be empty or decimal number */
if (!len || strspn(rate_node_name, "0123456789") == len)
return ERR_PTR(-EINVAL);
return devlink_rate_node_get_by_name(devlink, rate_node_name);
}
static struct devlink_rate *
devlink_rate_node_get_from_info(struct devlink *devlink, struct genl_info *info)
{
return devlink_rate_node_get_from_attrs(devlink, info->attrs);
}
static struct devlink_rate *
devlink_rate_get_from_info(struct devlink *devlink, struct genl_info *info)
{
struct nlattr **attrs = info->attrs;
if (attrs[DEVLINK_ATTR_PORT_INDEX])
return devlink_rate_leaf_get_from_info(devlink, info);
else if (attrs[DEVLINK_ATTR_RATE_NODE_NAME])
return devlink_rate_node_get_from_info(devlink, info);
else
return ERR_PTR(-EINVAL);
}
static int devlink_nl_rate_fill(struct sk_buff *msg,
struct devlink_rate *devlink_rate,
enum devlink_command cmd, u32 portid, u32 seq,
int flags, struct netlink_ext_ack *extack)
{
struct devlink *devlink = devlink_rate->devlink;
void *hdr;
hdr = genlmsg_put(msg, portid, seq, &devlink_nl_family, flags, cmd);
if (!hdr)
return -EMSGSIZE;
if (devlink_nl_put_handle(msg, devlink))
goto nla_put_failure;
if (nla_put_u16(msg, DEVLINK_ATTR_RATE_TYPE, devlink_rate->type))
goto nla_put_failure;
if (devlink_rate_is_leaf(devlink_rate)) {
if (nla_put_u32(msg, DEVLINK_ATTR_PORT_INDEX,
devlink_rate->devlink_port->index))
goto nla_put_failure;
} else if (devlink_rate_is_node(devlink_rate)) {
if (nla_put_string(msg, DEVLINK_ATTR_RATE_NODE_NAME,
devlink_rate->name))
goto nla_put_failure;
}
if (nla_put_u64_64bit(msg, DEVLINK_ATTR_RATE_TX_SHARE,
devlink_rate->tx_share, DEVLINK_ATTR_PAD))
goto nla_put_failure;
if (nla_put_u64_64bit(msg, DEVLINK_ATTR_RATE_TX_MAX,
devlink_rate->tx_max, DEVLINK_ATTR_PAD))
goto nla_put_failure;
if (nla_put_u32(msg, DEVLINK_ATTR_RATE_TX_PRIORITY,
devlink_rate->tx_priority))
goto nla_put_failure;
if (nla_put_u32(msg, DEVLINK_ATTR_RATE_TX_WEIGHT,
devlink_rate->tx_weight))
goto nla_put_failure;
if (devlink_rate->parent)
if (nla_put_string(msg, DEVLINK_ATTR_RATE_PARENT_NODE_NAME,
devlink_rate->parent->name))
goto nla_put_failure;
genlmsg_end(msg, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
static void devlink_rate_notify(struct devlink_rate *devlink_rate,
enum devlink_command cmd)
{
struct devlink *devlink = devlink_rate->devlink;
struct sk_buff *msg;
int err;
WARN_ON(cmd != DEVLINK_CMD_RATE_NEW && cmd != DEVLINK_CMD_RATE_DEL);
if (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
return;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return;
err = devlink_nl_rate_fill(msg, devlink_rate, cmd, 0, 0, 0, NULL);
if (err) {
nlmsg_free(msg);
return;
}
devlink_nl_notify_send(devlink, msg);
}
void devlink_rates_notify_register(struct devlink *devlink)
{
struct devlink_rate *rate_node;
list_for_each_entry(rate_node, &devlink->rate_list, list)
devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_NEW);
}
void devlink_rates_notify_unregister(struct devlink *devlink)
{
struct devlink_rate *rate_node;
list_for_each_entry_reverse(rate_node, &devlink->rate_list, list)
devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_DEL);
}
static int
devlink_nl_rate_get_dump_one(struct sk_buff *msg, struct devlink *devlink,
struct netlink_callback *cb, int flags)
{
struct devlink_nl_dump_state *state = devlink_dump_state(cb);
struct devlink_rate *devlink_rate;
int idx = 0;
int err = 0;
list_for_each_entry(devlink_rate, &devlink->rate_list, list) {
enum devlink_command cmd = DEVLINK_CMD_RATE_NEW;
u32 id = NETLINK_CB(cb->skb).portid;
if (idx < state->idx) {
idx++;
continue;
}
err = devlink_nl_rate_fill(msg, devlink_rate, cmd, id,
cb->nlh->nlmsg_seq, flags, NULL);
if (err) {
state->idx = idx;
break;
}
idx++;
}
return err;
}
int devlink_nl_rate_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
{
return devlink_nl_dumpit(skb, cb, devlink_nl_rate_get_dump_one);
}
int devlink_nl_rate_get_doit(struct sk_buff *skb, struct genl_info *info)
{
struct devlink *devlink = info->user_ptr[0];
struct devlink_rate *devlink_rate;
struct sk_buff *msg;
int err;
devlink_rate = devlink_rate_get_from_info(devlink, info);
if (IS_ERR(devlink_rate))
return PTR_ERR(devlink_rate);
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
err = devlink_nl_rate_fill(msg, devlink_rate, DEVLINK_CMD_RATE_NEW,
info->snd_portid, info->snd_seq, 0,
info->extack);
if (err) {
nlmsg_free(msg);
return err;
}
return genlmsg_reply(msg, info);
}
static bool
devlink_rate_is_parent_node(struct devlink_rate *devlink_rate,
struct devlink_rate *parent)
{
while (parent) {
if (parent == devlink_rate)
return true;
parent = parent->parent;
}
return false;
}
static int
devlink_nl_rate_parent_node_set(struct devlink_rate *devlink_rate,
struct genl_info *info,
struct nlattr *nla_parent)
{
struct devlink *devlink = devlink_rate->devlink;
const char *parent_name = nla_data(nla_parent);
const struct devlink_ops *ops = devlink->ops;
size_t len = strlen(parent_name);
struct devlink_rate *parent;
int err = -EOPNOTSUPP;
parent = devlink_rate->parent;
if (parent && !len) {
if (devlink_rate_is_leaf(devlink_rate))
err = ops->rate_leaf_parent_set(devlink_rate, NULL,
devlink_rate->priv, NULL,
info->extack);
else if (devlink_rate_is_node(devlink_rate))
err = ops->rate_node_parent_set(devlink_rate, NULL,
devlink_rate->priv, NULL,
info->extack);
if (err)
return err;
refcount_dec(&parent->refcnt);
devlink_rate->parent = NULL;
} else if (len) {
parent = devlink_rate_node_get_by_name(devlink, parent_name);
if (IS_ERR(parent))
return -ENODEV;
if (parent == devlink_rate) {
NL_SET_ERR_MSG(info->extack, "Parent to self is not allowed");
return -EINVAL;
}
if (devlink_rate_is_node(devlink_rate) &&
devlink_rate_is_parent_node(devlink_rate, parent->parent)) {
NL_SET_ERR_MSG(info->extack, "Node is already a parent of parent node.");
return -EEXIST;
}
if (devlink_rate_is_leaf(devlink_rate))
err = ops->rate_leaf_parent_set(devlink_rate, parent,
devlink_rate->priv, parent->priv,
info->extack);
else if (devlink_rate_is_node(devlink_rate))
err = ops->rate_node_parent_set(devlink_rate, parent,
devlink_rate->priv, parent->priv,
info->extack);
if (err)
return err;
if (devlink_rate->parent)
/* we're reassigning to other parent in this case */
refcount_dec(&devlink_rate->parent->refcnt);
refcount_inc(&parent->refcnt);
devlink_rate->parent = parent;
}
return 0;
}
static int devlink_nl_rate_set(struct devlink_rate *devlink_rate,
const struct devlink_ops *ops,
struct genl_info *info)
{
struct nlattr *nla_parent, **attrs = info->attrs;
int err = -EOPNOTSUPP;
u32 priority;
u32 weight;
u64 rate;
if (attrs[DEVLINK_ATTR_RATE_TX_SHARE]) {
rate = nla_get_u64(attrs[DEVLINK_ATTR_RATE_TX_SHARE]);
if (devlink_rate_is_leaf(devlink_rate))
err = ops->rate_leaf_tx_share_set(devlink_rate, devlink_rate->priv,
rate, info->extack);
else if (devlink_rate_is_node(devlink_rate))
err = ops->rate_node_tx_share_set(devlink_rate, devlink_rate->priv,
rate, info->extack);
if (err)
return err;
devlink_rate->tx_share = rate;
}
if (attrs[DEVLINK_ATTR_RATE_TX_MAX]) {
rate = nla_get_u64(attrs[DEVLINK_ATTR_RATE_TX_MAX]);
if (devlink_rate_is_leaf(devlink_rate))
err = ops->rate_leaf_tx_max_set(devlink_rate, devlink_rate->priv,
rate, info->extack);
else if (devlink_rate_is_node(devlink_rate))
err = ops->rate_node_tx_max_set(devlink_rate, devlink_rate->priv,
rate, info->extack);
if (err)
return err;
devlink_rate->tx_max = rate;
}
if (attrs[DEVLINK_ATTR_RATE_TX_PRIORITY]) {
priority = nla_get_u32(attrs[DEVLINK_ATTR_RATE_TX_PRIORITY]);
if (devlink_rate_is_leaf(devlink_rate))
err = ops->rate_leaf_tx_priority_set(devlink_rate, devlink_rate->priv,
priority, info->extack);
else if (devlink_rate_is_node(devlink_rate))
err = ops->rate_node_tx_priority_set(devlink_rate, devlink_rate->priv,
priority, info->extack);
if (err)
return err;
devlink_rate->tx_priority = priority;
}
if (attrs[DEVLINK_ATTR_RATE_TX_WEIGHT]) {
weight = nla_get_u32(attrs[DEVLINK_ATTR_RATE_TX_WEIGHT]);
if (devlink_rate_is_leaf(devlink_rate))
err = ops->rate_leaf_tx_weight_set(devlink_rate, devlink_rate->priv,
weight, info->extack);
else if (devlink_rate_is_node(devlink_rate))
err = ops->rate_node_tx_weight_set(devlink_rate, devlink_rate->priv,
weight, info->extack);
if (err)
return err;
devlink_rate->tx_weight = weight;
}
nla_parent = attrs[DEVLINK_ATTR_RATE_PARENT_NODE_NAME];
if (nla_parent) {
err = devlink_nl_rate_parent_node_set(devlink_rate, info,
nla_parent);
if (err)
return err;
}
return 0;
}
static bool devlink_rate_set_ops_supported(const struct devlink_ops *ops,
struct genl_info *info,
enum devlink_rate_type type)
{
struct nlattr **attrs = info->attrs;
if (type == DEVLINK_RATE_TYPE_LEAF) {
if (attrs[DEVLINK_ATTR_RATE_TX_SHARE] && !ops->rate_leaf_tx_share_set) {
NL_SET_ERR_MSG(info->extack, "TX share set isn't supported for the leafs");
return false;
}
if (attrs[DEVLINK_ATTR_RATE_TX_MAX] && !ops->rate_leaf_tx_max_set) {
NL_SET_ERR_MSG(info->extack, "TX max set isn't supported for the leafs");
return false;
}
if (attrs[DEVLINK_ATTR_RATE_PARENT_NODE_NAME] &&
!ops->rate_leaf_parent_set) {
NL_SET_ERR_MSG(info->extack, "Parent set isn't supported for the leafs");
return false;
}
if (attrs[DEVLINK_ATTR_RATE_TX_PRIORITY] && !ops->rate_leaf_tx_priority_set) {
NL_SET_ERR_MSG_ATTR(info->extack,
attrs[DEVLINK_ATTR_RATE_TX_PRIORITY],
"TX priority set isn't supported for the leafs");
return false;
}
if (attrs[DEVLINK_ATTR_RATE_TX_WEIGHT] && !ops->rate_leaf_tx_weight_set) {
NL_SET_ERR_MSG_ATTR(info->extack,
attrs[DEVLINK_ATTR_RATE_TX_WEIGHT],
"TX weight set isn't supported for the leafs");
return false;
}
} else if (type == DEVLINK_RATE_TYPE_NODE) {
if (attrs[DEVLINK_ATTR_RATE_TX_SHARE] && !ops->rate_node_tx_share_set) {
NL_SET_ERR_MSG(info->extack, "TX share set isn't supported for the nodes");
return false;
}
if (attrs[DEVLINK_ATTR_RATE_TX_MAX] && !ops->rate_node_tx_max_set) {
NL_SET_ERR_MSG(info->extack, "TX max set isn't supported for the nodes");
return false;
}
if (attrs[DEVLINK_ATTR_RATE_PARENT_NODE_NAME] &&
!ops->rate_node_parent_set) {
NL_SET_ERR_MSG(info->extack, "Parent set isn't supported for the nodes");
return false;
}
if (attrs[DEVLINK_ATTR_RATE_TX_PRIORITY] && !ops->rate_node_tx_priority_set) {
NL_SET_ERR_MSG_ATTR(info->extack,
attrs[DEVLINK_ATTR_RATE_TX_PRIORITY],
"TX priority set isn't supported for the nodes");
return false;
}
if (attrs[DEVLINK_ATTR_RATE_TX_WEIGHT] && !ops->rate_node_tx_weight_set) {
NL_SET_ERR_MSG_ATTR(info->extack,
attrs[DEVLINK_ATTR_RATE_TX_WEIGHT],
"TX weight set isn't supported for the nodes");
return false;
}
} else {
WARN(1, "Unknown type of rate object");
return false;
}
return true;
}
int devlink_nl_rate_set_doit(struct sk_buff *skb, struct genl_info *info)
{
struct devlink *devlink = info->user_ptr[0];
struct devlink_rate *devlink_rate;
const struct devlink_ops *ops;
int err;
devlink_rate = devlink_rate_get_from_info(devlink, info);
if (IS_ERR(devlink_rate))
return PTR_ERR(devlink_rate);
ops = devlink->ops;
if (!ops || !devlink_rate_set_ops_supported(ops, info, devlink_rate->type))
return -EOPNOTSUPP;
err = devlink_nl_rate_set(devlink_rate, ops, info);
if (!err)
devlink_rate_notify(devlink_rate, DEVLINK_CMD_RATE_NEW);
return err;
}
int devlink_nl_rate_new_doit(struct sk_buff *skb, struct genl_info *info)
{
struct devlink *devlink = info->user_ptr[0];
struct devlink_rate *rate_node;
const struct devlink_ops *ops;
int err;
ops = devlink->ops;
if (!ops || !ops->rate_node_new || !ops->rate_node_del) {
NL_SET_ERR_MSG(info->extack, "Rate nodes aren't supported");
return -EOPNOTSUPP;
}
if (!devlink_rate_set_ops_supported(ops, info, DEVLINK_RATE_TYPE_NODE))
return -EOPNOTSUPP;
rate_node = devlink_rate_node_get_from_attrs(devlink, info->attrs);
if (!IS_ERR(rate_node))
return -EEXIST;
else if (rate_node == ERR_PTR(-EINVAL))
return -EINVAL;
rate_node = kzalloc(sizeof(*rate_node), GFP_KERNEL);
if (!rate_node)
return -ENOMEM;
rate_node->devlink = devlink;
rate_node->type = DEVLINK_RATE_TYPE_NODE;
rate_node->name = nla_strdup(info->attrs[DEVLINK_ATTR_RATE_NODE_NAME], GFP_KERNEL);
if (!rate_node->name) {
err = -ENOMEM;
goto err_strdup;
}
err = ops->rate_node_new(rate_node, &rate_node->priv, info->extack);
if (err)
goto err_node_new;
err = devlink_nl_rate_set(rate_node, ops, info);
if (err)
goto err_rate_set;
refcount_set(&rate_node->refcnt, 1);
list_add(&rate_node->list, &devlink->rate_list);
devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_NEW);
return 0;
err_rate_set:
ops->rate_node_del(rate_node, rate_node->priv, info->extack);
err_node_new:
kfree(rate_node->name);
err_strdup:
kfree(rate_node);
return err;
}
int devlink_nl_rate_del_doit(struct sk_buff *skb, struct genl_info *info)
{
struct devlink *devlink = info->user_ptr[0];
struct devlink_rate *rate_node;
int err;
rate_node = devlink_rate_node_get_from_info(devlink, info);
if (IS_ERR(rate_node))
return PTR_ERR(rate_node);
if (refcount_read(&rate_node->refcnt) > 1) {
NL_SET_ERR_MSG(info->extack, "Node has children. Cannot delete node.");
return -EBUSY;
}
devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_DEL);
err = devlink->ops->rate_node_del(rate_node, rate_node->priv,
info->extack);
if (rate_node->parent)
refcount_dec(&rate_node->parent->refcnt);
list_del(&rate_node->list);
kfree(rate_node->name);
kfree(rate_node);
return err;
}
int devlink_rate_nodes_check(struct devlink *devlink, u16 mode,
struct netlink_ext_ack *extack)
{
struct devlink_rate *devlink_rate;
list_for_each_entry(devlink_rate, &devlink->rate_list, list)
if (devlink_rate_is_node(devlink_rate)) {
NL_SET_ERR_MSG(extack, "Rate node(s) exists.");
return -EBUSY;
}
return 0;
}
/**
* devl_rate_node_create - create devlink rate node
* @devlink: devlink instance
* @priv: driver private data
* @node_name: name of the resulting node
* @parent: parent devlink_rate struct
*
* Create devlink rate object of type node
*/
struct devlink_rate *
devl_rate_node_create(struct devlink *devlink, void *priv, char *node_name,
struct devlink_rate *parent)
{
struct devlink_rate *rate_node;
rate_node = devlink_rate_node_get_by_name(devlink, node_name);
if (!IS_ERR(rate_node))
return ERR_PTR(-EEXIST);
rate_node = kzalloc(sizeof(*rate_node), GFP_KERNEL);
if (!rate_node)
return ERR_PTR(-ENOMEM);
if (parent) {
rate_node->parent = parent;
refcount_inc(&rate_node->parent->refcnt);
}
rate_node->type = DEVLINK_RATE_TYPE_NODE;
rate_node->devlink = devlink;
rate_node->priv = priv;
rate_node->name = kstrdup(node_name, GFP_KERNEL);
if (!rate_node->name) {
kfree(rate_node);
return ERR_PTR(-ENOMEM);
}
refcount_set(&rate_node->refcnt, 1);
list_add(&rate_node->list, &devlink->rate_list);
devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_NEW);
return rate_node;
}
EXPORT_SYMBOL_GPL(devl_rate_node_create);
/**
* devl_rate_leaf_create - create devlink rate leaf
* @devlink_port: devlink port object to create rate object on
* @priv: driver private data
* @parent: parent devlink_rate struct
*
* Create devlink rate object of type leaf on provided @devlink_port.
*/
int devl_rate_leaf_create(struct devlink_port *devlink_port, void *priv,
struct devlink_rate *parent)
{
struct devlink *devlink = devlink_port->devlink;
struct devlink_rate *devlink_rate;
devl_assert_locked(devlink_port->devlink);
if (WARN_ON(devlink_port->devlink_rate))
return -EBUSY;
devlink_rate = kzalloc(sizeof(*devlink_rate), GFP_KERNEL);
if (!devlink_rate)
return -ENOMEM;
if (parent) {
devlink_rate->parent = parent;
refcount_inc(&devlink_rate->parent->refcnt);
}
devlink_rate->type = DEVLINK_RATE_TYPE_LEAF;
devlink_rate->devlink = devlink;
devlink_rate->devlink_port = devlink_port;
devlink_rate->priv = priv;
list_add_tail(&devlink_rate->list, &devlink->rate_list);
devlink_port->devlink_rate = devlink_rate;
devlink_rate_notify(devlink_rate, DEVLINK_CMD_RATE_NEW);
return 0;
}
EXPORT_SYMBOL_GPL(devl_rate_leaf_create);
/**
* devl_rate_leaf_destroy - destroy devlink rate leaf
*
* @devlink_port: devlink port linked to the rate object
*
* Destroy the devlink rate object of type leaf on provided @devlink_port.
*/
void devl_rate_leaf_destroy(struct devlink_port *devlink_port)
{
struct devlink_rate *devlink_rate = devlink_port->devlink_rate;
devl_assert_locked(devlink_port->devlink);
if (!devlink_rate)
return;
devlink_rate_notify(devlink_rate, DEVLINK_CMD_RATE_DEL);
if (devlink_rate->parent)
refcount_dec(&devlink_rate->parent->refcnt);
list_del(&devlink_rate->list);
devlink_port->devlink_rate = NULL;
kfree(devlink_rate);
}
EXPORT_SYMBOL_GPL(devl_rate_leaf_destroy);
/**
* devl_rate_nodes_destroy - destroy all devlink rate nodes on device
* @devlink: devlink instance
*
* Unset parent for all rate objects and destroy all rate nodes
* on specified device.
*/
void devl_rate_nodes_destroy(struct devlink *devlink)
{
static struct devlink_rate *devlink_rate, *tmp;
const struct devlink_ops *ops = devlink->ops;
devl_assert_locked(devlink);
list_for_each_entry(devlink_rate, &devlink->rate_list, list) {
if (!devlink_rate->parent)
continue;
refcount_dec(&devlink_rate->parent->refcnt);
if (devlink_rate_is_leaf(devlink_rate))
ops->rate_leaf_parent_set(devlink_rate, NULL, devlink_rate->priv,
NULL, NULL);
else if (devlink_rate_is_node(devlink_rate))
ops->rate_node_parent_set(devlink_rate, NULL, devlink_rate->priv,
NULL, NULL);
}
list_for_each_entry_safe(devlink_rate, tmp, &devlink->rate_list, list) {
if (devlink_rate_is_node(devlink_rate)) {
ops->rate_node_del(devlink_rate, devlink_rate->priv, NULL);
list_del(&devlink_rate->list);
kfree(devlink_rate->name);
kfree(devlink_rate);
}
}
}
EXPORT_SYMBOL_GPL(devl_rate_nodes_destroy);