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linux-next/net/batman-adv/hash.c
Sven Eckelmann 05abd7bcc9 batman-adv: Store modification counter via hash helpers
Multiple datastructures use the hash helper functions to add and remove
entries from the simple hlist based hashes. These are often also dumped to
userspace via netlink and thus should have a generation sequence counter.

Reported-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2018-11-12 10:41:51 +01:00

97 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2006-2018 B.A.T.M.A.N. contributors:
*
* Simon Wunderlich, Marek Lindner
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include "hash.h"
#include "main.h"
#include <linux/gfp.h>
#include <linux/lockdep.h>
#include <linux/slab.h>
/* clears the hash */
static void batadv_hash_init(struct batadv_hashtable *hash)
{
u32 i;
for (i = 0; i < hash->size; i++) {
INIT_HLIST_HEAD(&hash->table[i]);
spin_lock_init(&hash->list_locks[i]);
}
atomic_set(&hash->generation, 0);
}
/**
* batadv_hash_destroy() - Free only the hashtable and the hash itself
* @hash: hash object to destroy
*/
void batadv_hash_destroy(struct batadv_hashtable *hash)
{
kfree(hash->list_locks);
kfree(hash->table);
kfree(hash);
}
/**
* batadv_hash_new() - Allocates and clears the hashtable
* @size: number of hash buckets to allocate
*
* Return: newly allocated hashtable, NULL on errors
*/
struct batadv_hashtable *batadv_hash_new(u32 size)
{
struct batadv_hashtable *hash;
hash = kmalloc(sizeof(*hash), GFP_ATOMIC);
if (!hash)
return NULL;
hash->table = kmalloc_array(size, sizeof(*hash->table), GFP_ATOMIC);
if (!hash->table)
goto free_hash;
hash->list_locks = kmalloc_array(size, sizeof(*hash->list_locks),
GFP_ATOMIC);
if (!hash->list_locks)
goto free_table;
hash->size = size;
batadv_hash_init(hash);
return hash;
free_table:
kfree(hash->table);
free_hash:
kfree(hash);
return NULL;
}
/**
* batadv_hash_set_lock_class() - Set specific lockdep class for hash spinlocks
* @hash: hash object to modify
* @key: lockdep class key address
*/
void batadv_hash_set_lock_class(struct batadv_hashtable *hash,
struct lock_class_key *key)
{
u32 i;
for (i = 0; i < hash->size; i++)
lockdep_set_class(&hash->list_locks[i], key);
}