path: root/fs/ocfs2/cluster/nodemanager.c

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * Copyright (C) 2004, 2005 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that 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.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/slab.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"
#include "ver.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;

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

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);
	memcpy(map, cluster->cl_nodes_bitmap, sizeof(cluster->cl_nodes_bitmap));
	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,