提交 fb778ea1 编写于 作者: M Marek Lindner

batman-adv: protect each hash row with rcu locks

Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
上级 a775eb84
......@@ -27,13 +27,16 @@ static void hash_init(struct hashtable_t *hash)
{
int i;
for (i = 0 ; i < hash->size; i++)
for (i = 0 ; i < hash->size; i++) {
INIT_HLIST_HEAD(&hash->table[i]);
spin_lock_init(&hash->list_locks[i]);
}
}
/* free only the hashtable and the hash itself. */
void hash_destroy(struct hashtable_t *hash)
{
kfree(hash->list_locks);
kfree(hash->table);
kfree(hash);
}
......@@ -43,20 +46,33 @@ struct hashtable_t *hash_new(int size)
{
struct hashtable_t *hash;
hash = kmalloc(sizeof(struct hashtable_t) , GFP_ATOMIC);
hash = kmalloc(sizeof(struct hashtable_t), GFP_ATOMIC);
if (!hash)
return NULL;
hash->size = size;
hash->table = kmalloc(sizeof(struct element_t *) * size, GFP_ATOMIC);
if (!hash->table)
goto free_hash;
if (!hash->table) {
kfree(hash);
return NULL;
}
hash->list_locks = kmalloc(sizeof(spinlock_t) * size, GFP_ATOMIC);
if (!hash->list_locks)
goto free_table;
hash->size = size;
hash_init(hash);
return hash;
free_table:
kfree(hash->table);
free_hash:
kfree(hash);
return NULL;
}
void bucket_free_rcu(struct rcu_head *rcu)
{
struct element_t *bucket;
bucket = container_of(rcu, struct element_t, rcu);
kfree(bucket);
}
......@@ -39,10 +39,12 @@ typedef void (*hashdata_free_cb)(void *, void *);
struct element_t {
void *data; /* pointer to the data */
struct hlist_node hlist; /* bucket list pointer */
struct rcu_head rcu;
};
struct hashtable_t {
struct hlist_head *table; /* the hashtable itself, with the buckets */
struct hlist_head *table; /* the hashtable itself with the buckets */
spinlock_t *list_locks; /* spinlock for each hash list entry */
int size; /* size of hashtable */
};
......@@ -52,6 +54,8 @@ struct hashtable_t *hash_new(int size);
/* free only the hashtable and the hash itself. */
void hash_destroy(struct hashtable_t *hash);
void bucket_free_rcu(struct rcu_head *rcu);
/* remove the hash structure. if hashdata_free_cb != NULL, this function will be
* called to remove the elements inside of the hash. if you don't remove the
* elements, memory might be leaked. */
......@@ -61,19 +65,22 @@ static inline void hash_delete(struct hashtable_t *hash,
struct hlist_head *head;
struct hlist_node *walk, *safe;
struct element_t *bucket;
spinlock_t *list_lock; /* spinlock to protect write access */
int i;
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
list_lock = &hash->list_locks[i];
hlist_for_each_safe(walk, safe, head) {
bucket = hlist_entry(walk, struct element_t, hlist);
spin_lock_bh(list_lock);
hlist_for_each_entry_safe(bucket, walk, safe, head, hlist) {
if (free_cb)
free_cb(bucket->data, arg);
hlist_del(walk);
kfree(bucket);
hlist_del_rcu(walk);
call_rcu(&bucket->rcu, bucket_free_rcu);
}
spin_unlock_bh(list_lock);
}
hash_destroy(hash);
......@@ -88,29 +95,39 @@ static inline int hash_add(struct hashtable_t *hash,
struct hlist_head *head;
struct hlist_node *walk, *safe;
struct element_t *bucket;
spinlock_t *list_lock; /* spinlock to protect write access */
if (!hash)
return -1;
goto err;
index = choose(data, hash->size);
head = &hash->table[index];
list_lock = &hash->list_locks[index];
hlist_for_each_safe(walk, safe, head) {
bucket = hlist_entry(walk, struct element_t, hlist);
rcu_read_lock();
hlist_for_each_entry_safe(bucket, walk, safe, head, hlist) {
if (compare(bucket->data, data))
return -1;
goto err_unlock;
}
rcu_read_unlock();
/* no duplicate found in list, add new element */
bucket = kmalloc(sizeof(struct element_t), GFP_ATOMIC);
if (!bucket)
return -1;
goto err;
bucket->data = data;
hlist_add_head(&bucket->hlist, head);
spin_lock_bh(list_lock);
hlist_add_head_rcu(&bucket->hlist, head);
spin_unlock_bh(list_lock);
return 0;
err_unlock:
rcu_read_unlock();
err:
return -1;
}
/* removes data from hash, if found. returns pointer do data on success, so you
......@@ -125,25 +142,31 @@ static inline void *hash_remove(struct hashtable_t *hash,
struct hlist_node *walk;
struct element_t *bucket;
struct hlist_head *head;
void *data_save;
void *data_save = NULL;
index = choose(data, hash->size);
head = &hash->table[index];
spin_lock_bh(&hash->list_locks[index]);
hlist_for_each_entry(bucket, walk, head, hlist) {
if (compare(bucket->data, data)) {
data_save = bucket->data;
hlist_del(walk);
kfree(bucket);
return data_save;
hlist_del_rcu(walk);
call_rcu(&bucket->rcu, bucket_free_rcu);
break;
}
}
spin_unlock_bh(&hash->list_locks[index]);
return NULL;
return data_save;
}
/* finds data, based on the key in keydata. returns the found data on success,
* or NULL on error */
/**
* finds data, based on the key in keydata. returns the found data on success,
* or NULL on error
*
* caller must lock with rcu_read_lock() / rcu_read_unlock()
**/
static inline void *hash_find(struct hashtable_t *hash,
hashdata_compare_cb compare,
hashdata_choose_cb choose, void *keydata)
......@@ -152,6 +175,7 @@ static inline void *hash_find(struct hashtable_t *hash,
struct hlist_head *head;
struct hlist_node *walk;
struct element_t *bucket;
void *bucket_data = NULL;
if (!hash)
return NULL;
......@@ -159,13 +183,14 @@ static inline void *hash_find(struct hashtable_t *hash,
index = choose(keydata , hash->size);
head = &hash->table[index];
hlist_for_each(walk, head) {
bucket = hlist_entry(walk, struct element_t, hlist);
if (compare(bucket->data, keydata))
return bucket->data;
hlist_for_each_entry(bucket, walk, head, hlist) {
if (compare(bucket->data, keydata)) {
bucket_data = bucket->data;
break;
}
}
return NULL;
return bucket_data;
}
#endif /* _NET_BATMAN_ADV_HASH_H_ */
......@@ -220,9 +220,11 @@ static ssize_t bat_socket_write(struct file *file, const char __user *buff,
goto dst_unreach;
spin_lock_bh(&bat_priv->orig_hash_lock);
rcu_read_lock();
orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
compare_orig, choose_orig,
icmp_packet->dst));
rcu_read_unlock();
if (!orig_node)
goto unlock;
......
......@@ -150,9 +150,11 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
int size;
int hash_added;
rcu_read_lock();
orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
compare_orig, choose_orig,
addr));
rcu_read_unlock();
if (orig_node)
return orig_node;
......@@ -294,6 +296,7 @@ static void _purge_orig(struct bat_priv *bat_priv)
struct hlist_node *walk, *safe;
struct hlist_head *head;
struct element_t *bucket;
spinlock_t *list_lock; /* spinlock to protect write access */
struct orig_node *orig_node;
int i;
......@@ -305,22 +308,26 @@ static void _purge_orig(struct bat_priv *bat_priv)
/* for all origins... */
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
list_lock = &hash->list_locks[i];
spin_lock_bh(list_lock);
hlist_for_each_entry_safe(bucket, walk, safe, head, hlist) {
orig_node = bucket->data;
if (purge_orig_node(bat_priv, orig_node)) {
if (orig_node->gw_flags)
gw_node_delete(bat_priv, orig_node);
hlist_del(walk);
kfree(bucket);
hlist_del_rcu(walk);
call_rcu(&bucket->rcu, bucket_free_rcu);
free_orig_node(orig_node, bat_priv);
continue;
}
if (time_after(jiffies, orig_node->last_frag_packet +
msecs_to_jiffies(FRAG_TIMEOUT)))
frag_list_free(&orig_node->frag_list);
}
spin_unlock_bh(list_lock);
}
spin_unlock_bh(&bat_priv->orig_hash_lock);
......@@ -387,7 +394,8 @@ int orig_seq_print_text(struct seq_file *seq, void *offset)
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
hlist_for_each_entry(bucket, walk, head, hlist) {
rcu_read_lock();
hlist_for_each_entry_rcu(bucket, walk, head, hlist) {
orig_node = bucket->data;
if (!orig_node->router)
......@@ -408,17 +416,16 @@ int orig_seq_print_text(struct seq_file *seq, void *offset)
neigh_node->addr,
neigh_node->if_incoming->net_dev->name);
rcu_read_lock();
hlist_for_each_entry_rcu(neigh_node, node,
&orig_node->neigh_list, list) {
seq_printf(seq, " %pM (%3i)", neigh_node->addr,
neigh_node->tq_avg);
}
rcu_read_unlock();
seq_printf(seq, "\n");
batman_count++;
}
rcu_read_unlock();
}
spin_unlock_bh(&bat_priv->orig_hash_lock);
......@@ -476,18 +483,21 @@ int orig_hash_add_if(struct batman_if *batman_if, int max_if_num)
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
hlist_for_each_entry(bucket, walk, head, hlist) {
rcu_read_lock();
hlist_for_each_entry_rcu(bucket, walk, head, hlist) {
orig_node = bucket->data;
if (orig_node_add_if(orig_node, max_if_num) == -1)
goto err;
}
rcu_read_unlock();
}
spin_unlock_bh(&bat_priv->orig_hash_lock);
return 0;
err:
rcu_read_unlock();
spin_unlock_bh(&bat_priv->orig_hash_lock);
return -ENOMEM;
}
......@@ -562,7 +572,8 @@ int orig_hash_del_if(struct batman_if *batman_if, int max_if_num)
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
hlist_for_each_entry(bucket, walk, head, hlist) {
rcu_read_lock();
hlist_for_each_entry_rcu(bucket, walk, head, hlist) {
orig_node = bucket->data;
ret = orig_node_del_if(orig_node, max_if_num,
......@@ -571,6 +582,7 @@ int orig_hash_del_if(struct batman_if *batman_if, int max_if_num)
if (ret == -1)
goto err;
}
rcu_read_unlock();
}
/* renumber remaining batman interfaces _inside_ of orig_hash_lock */
......@@ -595,6 +607,7 @@ int orig_hash_del_if(struct batman_if *batman_if, int max_if_num)
return 0;
err:
rcu_read_unlock();
spin_unlock_bh(&bat_priv->orig_hash_lock);
return -ENOMEM;
}
......@@ -52,7 +52,8 @@ void slide_own_bcast_window(struct batman_if *batman_if)
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
hlist_for_each_entry(bucket, walk, head, hlist) {
rcu_read_lock();
hlist_for_each_entry_rcu(bucket, walk, head, hlist) {
orig_node = bucket->data;
word_index = batman_if->if_num * NUM_WORDS;
word = &(orig_node->bcast_own[word_index]);
......@@ -61,6 +62,7 @@ void slide_own_bcast_window(struct batman_if *batman_if)
orig_node->bcast_own_sum[batman_if->if_num] =
bit_packet_count(word);
}
rcu_read_unlock();
}
spin_unlock_bh(&bat_priv->orig_hash_lock);
......@@ -873,9 +875,11 @@ static int recv_my_icmp_packet(struct bat_priv *bat_priv,
/* answer echo request (ping) */
/* get routing information */
spin_lock_bh(&bat_priv->orig_hash_lock);
rcu_read_lock();
orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
compare_orig, choose_orig,
icmp_packet->orig));
rcu_read_unlock();
ret = NET_RX_DROP;
if ((orig_node) && (orig_node->router)) {
......@@ -931,9 +935,11 @@ static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
/* get routing information */
spin_lock_bh(&bat_priv->orig_hash_lock);
rcu_read_lock();
orig_node = ((struct orig_node *)
hash_find(bat_priv->orig_hash, compare_orig, choose_orig,
icmp_packet->orig));
rcu_read_unlock();
ret = NET_RX_DROP;
if ((orig_node) && (orig_node->router)) {
......@@ -1023,9 +1029,11 @@ int recv_icmp_packet(struct sk_buff *skb, struct batman_if *recv_if)
/* get routing information */
spin_lock_bh(&bat_priv->orig_hash_lock);
rcu_read_lock();
orig_node = ((struct orig_node *)
hash_find(bat_priv->orig_hash, compare_orig, choose_orig,
icmp_packet->dst));
rcu_read_unlock();
if ((orig_node) && (orig_node->router)) {
......@@ -1094,9 +1102,11 @@ struct neigh_node *find_router(struct bat_priv *bat_priv,
router_orig->orig, ETH_ALEN) == 0) {
primary_orig_node = router_orig;
} else {
rcu_read_lock();
primary_orig_node = hash_find(bat_priv->orig_hash, compare_orig,
choose_orig,
router_orig->primary_addr);
rcu_read_unlock();
if (!primary_orig_node)
return orig_node->router;
......@@ -1199,9 +1209,11 @@ int route_unicast_packet(struct sk_buff *skb, struct batman_if *recv_if,
/* get routing information */
spin_lock_bh(&bat_priv->orig_hash_lock);
rcu_read_lock();
orig_node = ((struct orig_node *)
hash_find(bat_priv->orig_hash, compare_orig, choose_orig,
unicast_packet->dest));
rcu_read_unlock();
router = find_router(bat_priv, orig_node, recv_if);
......@@ -1345,9 +1357,11 @@ int recv_bcast_packet(struct sk_buff *skb, struct batman_if *recv_if)
return NET_RX_DROP;
spin_lock_bh(&bat_priv->orig_hash_lock);
rcu_read_lock();
orig_node = ((struct orig_node *)
hash_find(bat_priv->orig_hash, compare_orig, choose_orig,
bcast_packet->orig));
rcu_read_unlock();
if (!orig_node) {
spin_unlock_bh(&bat_priv->orig_hash_lock);
......
......@@ -60,10 +60,12 @@ void hna_local_add(struct net_device *soft_iface, uint8_t *addr)
int required_bytes;
spin_lock_bh(&bat_priv->hna_lhash_lock);
rcu_read_lock();
hna_local_entry =
((struct hna_local_entry *)hash_find(bat_priv->hna_local_hash,
compare_orig, choose_orig,
addr));
rcu_read_unlock();
spin_unlock_bh(&bat_priv->hna_lhash_lock);
if (hna_local_entry) {
......@@ -116,9 +118,11 @@ void hna_local_add(struct net_device *soft_iface, uint8_t *addr)
/* remove address from global hash if present */
spin_lock_bh(&bat_priv->hna_ghash_lock);
rcu_read_lock();
hna_global_entry = ((struct hna_global_entry *)
hash_find(bat_priv->hna_global_hash,
compare_orig, choose_orig, addr));
rcu_read_unlock();
if (hna_global_entry)
_hna_global_del_orig(bat_priv, hna_global_entry,
......@@ -252,9 +256,11 @@ void hna_local_remove(struct bat_priv *bat_priv,
spin_lock_bh(&bat_priv->hna_lhash_lock);
rcu_read_lock();
hna_local_entry = (struct hna_local_entry *)
hash_find(bat_priv->hna_local_hash, compare_orig, choose_orig,
addr);
rcu_read_unlock();
if (hna_local_entry)
hna_local_del(bat_priv, hna_local_entry, message);
......@@ -334,9 +340,11 @@ void hna_global_add_orig(struct bat_priv *bat_priv,
spin_lock_bh(&bat_priv->hna_ghash_lock);
hna_ptr = hna_buff + (hna_buff_count * ETH_ALEN);
rcu_read_lock();
hna_global_entry = (struct hna_global_entry *)
hash_find(bat_priv->hna_global_hash, compare_orig,
choose_orig, hna_ptr);
rcu_read_unlock();
if (!hna_global_entry) {
spin_unlock_bh(&bat_priv->hna_ghash_lock);
......@@ -368,9 +376,11 @@ void hna_global_add_orig(struct bat_priv *bat_priv,
spin_lock_bh(&bat_priv->hna_lhash_lock);
hna_ptr = hna_buff + (hna_buff_count * ETH_ALEN);
rcu_read_lock();
hna_local_entry = (struct hna_local_entry *)
hash_find(bat_priv->hna_local_hash, compare_orig,
choose_orig, hna_ptr);
rcu_read_unlock();
if (hna_local_entry)
hna_local_del(bat_priv, hna_local_entry,
......@@ -483,9 +493,11 @@ void hna_global_del_orig(struct bat_priv *bat_priv,
while ((hna_buff_count + 1) * ETH_ALEN <= orig_node->hna_buff_len) {
hna_ptr = orig_node->hna_buff + (hna_buff_count * ETH_ALEN);
rcu_read_lock();
hna_global_entry = (struct hna_global_entry *)
hash_find(bat_priv->hna_global_hash, compare_orig,
choose_orig, hna_ptr);
rcu_read_unlock();
if ((hna_global_entry) &&
(hna_global_entry->orig_node == orig_node))
......@@ -521,9 +533,11 @@ struct orig_node *transtable_search(struct bat_priv *bat_priv, uint8_t *addr)
struct hna_global_entry *hna_global_entry;
spin_lock_bh(&bat_priv->hna_ghash_lock);
rcu_read_lock();
hna_global_entry = (struct hna_global_entry *)
hash_find(bat_priv->hna_global_hash,
compare_orig, choose_orig, addr);
rcu_read_unlock();
spin_unlock_bh(&bat_priv->hna_ghash_lock);
if (!hna_global_entry)
......
......@@ -179,9 +179,11 @@ int frag_reassemble_skb(struct sk_buff *skb, struct bat_priv *bat_priv,
*new_skb = NULL;
spin_lock_bh(&bat_priv->orig_hash_lock);
rcu_read_lock();
orig_node = ((struct orig_node *)
hash_find(bat_priv->orig_hash, compare_orig, choose_orig,
unicast_packet->orig));
rcu_read_unlock();
if (!orig_node) {
pr_debug("couldn't find originator in orig_hash\n");
......
......@@ -380,8 +380,10 @@ static struct vis_info *add_packet(struct bat_priv *bat_priv,
sizeof(struct vis_packet));
memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
rcu_read_lock();
old_info = hash_find(bat_priv->vis_hash, vis_info_cmp, vis_info_choose,
&search_elem);
rcu_read_unlock();
kfree_skb(search_elem.skb_packet);
if (old_info) {
......@@ -540,7 +542,8 @@ static int find_best_vis_server(struct bat_priv *bat_priv,
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
hlist_for_each_entry(bucket, walk, head, hlist) {
rcu_read_lock();
hlist_for_each_entry_rcu(bucket, walk, head, hlist) {
orig_node = bucket->data;
if ((orig_node) && (orig_node->router) &&
(orig_node->flags & VIS_SERVER) &&
......@@ -550,6 +553,7 @@ static int find_best_vis_server(struct bat_priv *bat_priv,
ETH_ALEN);
}
}
rcu_read_unlock();
}
return best_tq;
......@@ -605,7 +609,8 @@ static int generate_vis_packet(struct bat_priv *bat_priv)
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
hlist_for_each_entry(bucket, walk, head, hlist) {
rcu_read_lock();
hlist_for_each_entry_rcu(bucket, walk, head, hlist) {
orig_node = bucket->data;
neigh_node = orig_node->router;
......@@ -632,10 +637,12 @@ static int generate_vis_packet(struct bat_priv *bat_priv)
packet->entries++;
if (vis_packet_full(info)) {
rcu_read_unlock();
spin_unlock_bh(&bat_priv->orig_hash_lock);
return 0;
}
}
rcu_read_unlock();
}
spin_unlock_bh(&bat_priv->orig_hash_lock);
......@@ -721,7 +728,8 @@ static void broadcast_vis_packet(struct bat_priv *bat_priv,
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
hlist_for_each_entry(bucket, walk, head, hlist) {
rcu_read_lock();
hlist_for_each_entry_rcu(bucket, walk, head, hlist) {
orig_node = bucket->data;
/* if it's a vis server and reachable, send it. */
......@@ -746,7 +754,7 @@ static void broadcast_vis_packet(struct bat_priv *bat_priv,
spin_lock_bh(&bat_priv->orig_hash_lock);
}
rcu_read_unlock();
}
spin_unlock_bh(&bat_priv->orig_hash_lock);
......@@ -763,9 +771,11 @@ static void unicast_vis_packet(struct bat_priv *bat_priv,
spin_lock_bh(&bat_priv->orig_hash_lock);
packet = (struct vis_packet *)info->skb_packet->data;
rcu_read_lock();
orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
compare_orig, choose_orig,
packet->target_orig));
rcu_read_unlock();
if ((!orig_node) || (!orig_node->router))
goto out;
......
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