/*
 * 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
 * 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.
 */

#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/jhash.h>
#include <linux/namei.h>
#include <linux/slab.h>
#include <linux/pagemap.h>

#include "netfs.h"

static int pohmelfs_cmp_hash(struct pohmelfs_name *n, u32 hash)
{
	if (n->hash > hash)
		return -1;
	if (n->hash < hash)
		return 1;

	return 0;
}

static struct pohmelfs_name *pohmelfs_search_hash_unprecise(struct pohmelfs_inode *pi, u32 hash)
{
	struct rb_node *n = pi->hash_root.rb_node;
	struct pohmelfs_name *tmp = NULL;
	int cmp;

	while (n) {
		tmp = rb_entry(n, struct pohmelfs_name, hash_node);

		cmp = pohmelfs_cmp_hash(tmp, hash);
		if (cmp < 0)
			n = n->rb_left;
		else if (cmp > 0)
			n = n->rb_right;
		else
			break;

	}

	return tmp;
}

struct pohmelfs_name *pohmelfs_search_hash(struct pohmelfs_inode *pi, u32 hash)
{
	struct pohmelfs_name *tmp;

	tmp = pohmelfs_search_hash_unprecise(pi, hash);
	if (tmp && (tmp->hash == hash))
		return tmp;

	return NULL;
}

static void __pohmelfs_name_del(struct pohmelfs_inode *parent, struct pohmelfs_name *node)
{
	rb_erase(&node->hash_node, &parent->hash_root);
}

/*
 * Remove name cache entry from its caches and free it.
 */
static void pohmelfs_name_free(struct pohmelfs_inode *parent, struct pohmelfs_name *node)
{
	__pohmelfs_name_del(parent, node);
	list_del(&node->sync_create_entry);
	kfree(node);
}

static struct pohmelfs_name *pohmelfs_insert_hash(struct pohmelfs_inode *pi,
		struct pohmelfs_name *new)
{
	struct rb_node **n = &pi->hash_root.rb_node, *parent = NULL;
	struct pohmelfs_name *ret = NULL, *tmp;
	int cmp;

	while (*n) {
		parent = *n;

		tmp = rb_entry(parent, struct pohmelfs_name, hash_node);

		cmp = pohmelfs_cmp_hash(tmp, new->hash);
		if (cmp < 0)
			n = &parent->rb_left;
		else if (cmp > 0)
			n = &parent->rb_right;
		else {
			ret = tmp;
			break;
		}
	}

	if (ret) {
		printk("%s: exist: parent: %llu, ino: %llu, hash: %x, len: %u, data: '%s', "
					"new: ino: %llu, hash: %x, len: %u, data: '%s'.\n",
				__func__, pi->ino,
				ret->ino, ret->hash, ret->len, ret->data,
				new->ino, new->hash, new->len, new->data);
		ret->ino = new->ino;
		return ret;
	}

	rb_link_node(&new->hash_node, parent, n);
	rb_insert_color(&new->hash_node, &pi->hash_root);

	return NULL;
}

/*
 * Free name cache for given inode.
 */
void pohmelfs_free_names(struct pohmelfs_inode *parent)
{
	struct rb_node *rb_node;
	struct pohmelfs_name *n;

	for (rb_node =