The following commit has been merged in the next branch:
commit 2b8171c4da6f31237f759a5b69dc8d21327542f7
Author: Marek Lindner <lindner_marek(a)yahoo.de>
Date: Wed Jan 19 20:01:40 2011 +0000
batman-adv: protect each hash row with rcu locks
Signed-off-by: Marek Lindner <lindner_marek(a)yahoo.de>
diff --git a/hash.c b/hash.c
index fa26939..0265366 100644
--- a/hash.c
+++ b/hash.c
@@ -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);
}
diff --git a/hash.h b/hash.h
index eae2440..3c48c6b 100644
--- a/hash.h
+++ b/hash.h
@@ -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_ */
diff --git a/icmp_socket.c b/icmp_socket.c
index 319a7cc..8e0cd8a 100644
--- a/icmp_socket.c
+++ b/icmp_socket.c
@@ -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;
diff --git a/originator.c b/originator.c
index 899d494..5c32314 100644
--- a/originator.c
+++ b/originator.c
@@ -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;
}
diff --git a/routing.c b/routing.c
index c15e6c1..32ae04e 100644
--- a/routing.c
+++ b/routing.c
@@ -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);
diff --git a/translation-table.c b/translation-table.c
index 7fb6726..b25e4b3 100644
--- a/translation-table.c
+++ b/translation-table.c
@@ -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)
diff --git a/unicast.c b/unicast.c
index 121b11d..2bc88db 100644
--- a/unicast.c
+++ b/unicast.c
@@ -184,9 +184,11 @@ 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");
diff --git a/vis.c b/vis.c
index 7db9ad8..d1b9f47 100644
--- a/vis.c
+++ b/vis.c
@@ -381,8 +381,10 @@ 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) {
@@ -541,7 +543,8 @@ 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) &&
@@ -551,6 +554,7 @@ static int find_best_vis_server(struct bat_priv *bat_priv,
ETH_ALEN);
}
}
+ rcu_read_unlock();
}
return best_tq;
@@ -606,7 +610,8 @@ 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;
@@ -633,10 +638,12 @@ 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);
@@ -722,7 +729,8 @@ 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. */
@@ -747,7 +755,7 @@ 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);
@@ -764,9 +772,11 @@ 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;
--
batman-adv
