batman-adv: protect the local and the global trans-tables with rcu
The local and the global translation-tables are now lock free and rcu
protected.
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index d516d85..5f1fcd5 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -80,6 +80,9 @@
if (!compare_eth(tt_local_entry, data))
continue;
+ if (!atomic_inc_not_zero(&tt_local_entry->refcount))
+ continue;
+
tt_local_entry_tmp = tt_local_entry;
break;
}
@@ -109,6 +112,9 @@
if (!compare_eth(tt_global_entry, data))
continue;
+ if (!atomic_inc_not_zero(&tt_global_entry->refcount))
+ continue;
+
tt_global_entry_tmp = tt_global_entry;
break;
}
@@ -125,8 +131,20 @@
return time_after(jiffies, deadline);
}
+static void tt_local_entry_free_ref(struct tt_local_entry *tt_local_entry)
+{
+ if (atomic_dec_and_test(&tt_local_entry->refcount))
+ kfree_rcu(tt_local_entry, rcu);
+}
+
+static void tt_global_entry_free_ref(struct tt_global_entry *tt_global_entry)
+{
+ if (atomic_dec_and_test(&tt_global_entry->refcount))
+ kfree_rcu(tt_global_entry, rcu);
+}
+
static void tt_local_event(struct bat_priv *bat_priv, uint8_t op,
- const uint8_t *addr, uint8_t roaming)
+ const uint8_t *addr, bool roaming)
{
struct tt_change_node *tt_change_node;
@@ -171,21 +189,19 @@
void tt_local_add(struct net_device *soft_iface, const uint8_t *addr)
{
struct bat_priv *bat_priv = netdev_priv(soft_iface);
- struct tt_local_entry *tt_local_entry;
- struct tt_global_entry *tt_global_entry;
- uint8_t roam_addr[ETH_ALEN];
+ struct tt_local_entry *tt_local_entry = NULL;
+ struct tt_global_entry *tt_global_entry = NULL;
- spin_lock_bh(&bat_priv->tt_lhash_lock);
tt_local_entry = tt_local_hash_find(bat_priv, addr);
if (tt_local_entry) {
tt_local_entry->last_seen = jiffies;
- goto unlock;
+ goto out;
}
tt_local_entry = kmalloc(sizeof(*tt_local_entry), GFP_ATOMIC);
if (!tt_local_entry)
- goto unlock;
+ goto out;
tt_local_event(bat_priv, NO_FLAGS, addr, false);
@@ -195,6 +211,7 @@
memcpy(tt_local_entry->addr, addr, ETH_ALEN);
tt_local_entry->last_seen = jiffies;
+ atomic_set(&tt_local_entry->refcount, 2);
/* the batman interface mac address should never be purged */
if (compare_eth(addr, soft_iface->dev_addr))
@@ -204,30 +221,26 @@
hash_add(bat_priv->tt_local_hash, compare_ltt, choose_orig,
tt_local_entry, &tt_local_entry->hash_entry);
+
atomic_inc(&bat_priv->num_local_tt);
- spin_unlock_bh(&bat_priv->tt_lhash_lock);
/* remove address from global hash if present */
- spin_lock_bh(&bat_priv->tt_ghash_lock);
-
tt_global_entry = tt_global_hash_find(bat_priv, addr);
/* Check whether it is a roaming! */
if (tt_global_entry) {
- memcpy(roam_addr, tt_global_entry->addr, ETH_ALEN);
/* This node is probably going to update its tt table */
tt_global_entry->orig_node->tt_poss_change = true;
_tt_global_del(bat_priv, tt_global_entry,
"local tt received");
- spin_unlock_bh(&bat_priv->tt_ghash_lock);
send_roam_adv(bat_priv, tt_global_entry->addr,
- tt_global_entry->orig_node);
- } else
- spin_unlock_bh(&bat_priv->tt_ghash_lock);
-
- return;
-unlock:
- spin_unlock_bh(&bat_priv->tt_lhash_lock);
+ tt_global_entry->orig_node);
+ }
+out:
+ if (tt_local_entry)
+ tt_local_entry_free_ref(tt_local_entry);
+ if (tt_global_entry)
+ tt_global_entry_free_ref(tt_global_entry);
}
int tt_changes_fill_buffer(struct bat_priv *bat_priv,
@@ -309,8 +322,6 @@
"announced via TT (TTVN: %u):\n",
net_dev->name, (uint8_t)atomic_read(&bat_priv->ttvn));
- spin_lock_bh(&bat_priv->tt_lhash_lock);
-
buf_size = 1;
/* Estimate length for: " * xx:xx:xx:xx:xx:xx\n" */
for (i = 0; i < hash->size; i++) {
@@ -324,7 +335,6 @@
buff = kmalloc(buf_size, GFP_ATOMIC);
if (!buff) {
- spin_unlock_bh(&bat_priv->tt_lhash_lock);
ret = -ENOMEM;
goto out;
}
@@ -344,8 +354,6 @@
rcu_read_unlock();
}
- spin_unlock_bh(&bat_priv->tt_lhash_lock);
-
seq_printf(seq, "%s", buff);
kfree(buff);
out:
@@ -354,15 +362,6 @@
return ret;
}
-static void tt_local_entry_free(struct hlist_node *node, void *arg)
-{
- struct bat_priv *bat_priv = arg;
- void *data = container_of(node, struct tt_local_entry, hash_entry);
-
- kfree(data);
- atomic_dec(&bat_priv->num_local_tt);
-}
-
static void tt_local_del(struct bat_priv *bat_priv,
struct tt_local_entry *tt_local_entry,
const char *message)
@@ -375,23 +374,24 @@
hash_remove(bat_priv->tt_local_hash, compare_ltt, choose_orig,
tt_local_entry->addr);
- tt_local_entry_free(&tt_local_entry->hash_entry, bat_priv);
+ tt_local_entry_free_ref(tt_local_entry);
}
void tt_local_remove(struct bat_priv *bat_priv, const uint8_t *addr,
const char *message, bool roaming)
{
- struct tt_local_entry *tt_local_entry;
+ struct tt_local_entry *tt_local_entry = NULL;
- spin_lock_bh(&bat_priv->tt_lhash_lock);
tt_local_entry = tt_local_hash_find(bat_priv, addr);
- if (tt_local_entry) {
- tt_local_event(bat_priv, TT_CHANGE_DEL, tt_local_entry->addr,
- roaming);
- tt_local_del(bat_priv, tt_local_entry, message);
- }
- spin_unlock_bh(&bat_priv->tt_lhash_lock);
+ if (!tt_local_entry)
+ goto out;
+
+ tt_local_event(bat_priv, TT_CHANGE_DEL, tt_local_entry->addr, roaming);
+ tt_local_del(bat_priv, tt_local_entry, message);
+out:
+ if (tt_local_entry)
+ tt_local_entry_free_ref(tt_local_entry);
}
static void tt_local_purge(struct bat_priv *bat_priv)
@@ -400,40 +400,45 @@
struct tt_local_entry *tt_local_entry;
struct hlist_node *node, *node_tmp;
struct hlist_head *head;
+ spinlock_t *list_lock; /* protects write access to the hash lists */
int i;
- spin_lock_bh(&bat_priv->tt_lhash_lock);
-
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(tt_local_entry, node, node_tmp,
head, hash_entry) {
if (tt_local_entry->never_purge)
continue;
if (!is_out_of_time(tt_local_entry->last_seen,
- TT_LOCAL_TIMEOUT * 1000))
+ TT_LOCAL_TIMEOUT * 1000))
continue;
tt_local_event(bat_priv, TT_CHANGE_DEL,
tt_local_entry->addr, false);
- tt_local_del(bat_priv, tt_local_entry,
- "address timed out");
+ atomic_dec(&bat_priv->num_local_tt);
+ bat_dbg(DBG_TT, bat_priv, "Deleting local "
+ "tt entry (%pM): timed out\n",
+ tt_local_entry->addr);
+ hlist_del_rcu(node);
+ tt_local_entry_free_ref(tt_local_entry);
}
+ spin_unlock_bh(list_lock);
}
- spin_unlock_bh(&bat_priv->tt_lhash_lock);
}
static void tt_local_table_free(struct bat_priv *bat_priv)
{
struct hashtable_t *hash;
- int i;
spinlock_t *list_lock; /* protects write access to the hash lists */
- struct hlist_head *head;
- struct hlist_node *node, *node_tmp;
struct tt_local_entry *tt_local_entry;
+ struct hlist_node *node, *node_tmp;
+ struct hlist_head *head;
+ int i;
if (!bat_priv->tt_local_hash)
return;
@@ -448,7 +453,7 @@
hlist_for_each_entry_safe(tt_local_entry, node, node_tmp,
head, hash_entry) {
hlist_del_rcu(node);
- kfree(tt_local_entry);
+ tt_local_entry_free_ref(tt_local_entry);
}
spin_unlock_bh(list_lock);
}
@@ -492,10 +497,9 @@
const unsigned char *tt_addr, uint8_t ttvn, bool roaming)
{
struct tt_global_entry *tt_global_entry;
- struct tt_local_entry *tt_local_entry;
struct orig_node *orig_node_tmp;
+ int ret = 0;
- spin_lock_bh(&bat_priv->tt_ghash_lock);
tt_global_entry = tt_global_hash_find(bat_priv, tt_addr);
if (!tt_global_entry) {
@@ -503,7 +507,8 @@
kmalloc(sizeof(*tt_global_entry),
GFP_ATOMIC);
if (!tt_global_entry)
- goto unlock;
+ goto out;
+
memcpy(tt_global_entry->addr, tt_addr, ETH_ALEN);
/* Assign the new orig_node */
atomic_inc(&orig_node->refcount);
@@ -511,10 +516,12 @@
tt_global_entry->ttvn = ttvn;
tt_global_entry->flags = NO_FLAGS;
tt_global_entry->roam_at = 0;
- atomic_inc(&orig_node->tt_size);
+ atomic_set(&tt_global_entry->refcount, 2);
+
hash_add(bat_priv->tt_global_hash, compare_gtt,
choose_orig, tt_global_entry,
&tt_global_entry->hash_entry);
+ atomic_inc(&orig_node->tt_size);
} else {
if (tt_global_entry->orig_node != orig_node) {
atomic_dec(&tt_global_entry->orig_node->tt_size);
@@ -529,25 +536,18 @@
tt_global_entry->roam_at = 0;
}
- spin_unlock_bh(&bat_priv->tt_ghash_lock);
-
bat_dbg(DBG_TT, bat_priv,
"Creating new global tt entry: %pM (via %pM)\n",
tt_global_entry->addr, orig_node->orig);
/* remove address from local hash if present */
- spin_lock_bh(&bat_priv->tt_lhash_lock);
- tt_local_entry = tt_local_hash_find(bat_priv, tt_addr);
-
- if (tt_local_entry)
- tt_local_remove(bat_priv, tt_global_entry->addr,
- "global tt received", roaming);
-
- spin_unlock_bh(&bat_priv->tt_lhash_lock);
- return 1;
-unlock:
- spin_unlock_bh(&bat_priv->tt_ghash_lock);
- return 0;
+ tt_local_remove(bat_priv, tt_global_entry->addr,
+ "global tt received", roaming);
+ ret = 1;
+out:
+ if (tt_global_entry)
+ tt_global_entry_free_ref(tt_global_entry);
+ return ret;
}
int tt_global_seq_print_text(struct seq_file *seq, void *offset)
@@ -584,8 +584,6 @@
seq_printf(seq, " %-13s %s %-15s %s\n",
"Client", "(TTVN)", "Originator", "(Curr TTVN)");
- spin_lock_bh(&bat_priv->tt_ghash_lock);
-
buf_size = 1;
/* Estimate length for: " * xx:xx:xx:xx:xx:xx (ttvn) via
* xx:xx:xx:xx:xx:xx (cur_ttvn)\n"*/
@@ -600,10 +598,10 @@
buff = kmalloc(buf_size, GFP_ATOMIC);
if (!buff) {
- spin_unlock_bh(&bat_priv->tt_ghash_lock);
ret = -ENOMEM;
goto out;
}
+
buff[0] = '\0';
pos = 0;
@@ -625,8 +623,6 @@
rcu_read_unlock();
}
- spin_unlock_bh(&bat_priv->tt_ghash_lock);
-
seq_printf(seq, "%s", buff);
kfree(buff);
out:
@@ -640,7 +636,7 @@
const char *message)
{
if (!tt_global_entry)
- return;
+ goto out;
bat_dbg(DBG_TT, bat_priv,
"Deleting global tt entry %pM (via %pM): %s\n",
@@ -648,31 +644,35 @@
message);
atomic_dec(&tt_global_entry->orig_node->tt_size);
+
hash_remove(bat_priv->tt_global_hash, compare_gtt, choose_orig,
tt_global_entry->addr);
- kfree(tt_global_entry);
+out:
+ if (tt_global_entry)
+ tt_global_entry_free_ref(tt_global_entry);
}
void tt_global_del(struct bat_priv *bat_priv,
struct orig_node *orig_node, const unsigned char *addr,
const char *message, bool roaming)
{
- struct tt_global_entry *tt_global_entry;
+ struct tt_global_entry *tt_global_entry = NULL;
- spin_lock_bh(&bat_priv->tt_ghash_lock);
tt_global_entry = tt_global_hash_find(bat_priv, addr);
+ if (!tt_global_entry)
+ goto out;
- if (tt_global_entry && tt_global_entry->orig_node == orig_node) {
+ if (tt_global_entry->orig_node == orig_node) {
if (roaming) {
tt_global_entry->flags |= TT_CLIENT_ROAM;
tt_global_entry->roam_at = jiffies;
goto out;
}
- atomic_dec(&orig_node->tt_size);
_tt_global_del(bat_priv, tt_global_entry, message);
}
out:
- spin_unlock_bh(&bat_priv->tt_ghash_lock);
+ if (tt_global_entry)
+ tt_global_entry_free_ref(tt_global_entry);
}
void tt_global_del_orig(struct bat_priv *bat_priv,
@@ -683,30 +683,28 @@
struct hashtable_t *hash = bat_priv->tt_global_hash;
struct hlist_node *node, *safe;
struct hlist_head *head;
+ spinlock_t *list_lock; /* protects write access to the hash lists */
- if (!bat_priv->tt_global_hash)
- return;
-
- spin_lock_bh(&bat_priv->tt_ghash_lock);
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(tt_global_entry, node, safe,
head, hash_entry) {
- if (tt_global_entry->orig_node == orig_node)
- _tt_global_del(bat_priv, tt_global_entry,
- message);
+ if (tt_global_entry->orig_node == orig_node) {
+ bat_dbg(DBG_TT, bat_priv,
+ "Deleting global tt entry %pM "
+ "(via %pM): originator time out\n",
+ tt_global_entry->addr,
+ tt_global_entry->orig_node->orig);
+ hlist_del_rcu(node);
+ tt_global_entry_free_ref(tt_global_entry);
+ }
}
+ spin_unlock_bh(list_lock);
}
atomic_set(&orig_node->tt_size, 0);
-
- spin_unlock_bh(&bat_priv->tt_ghash_lock);
-}
-
-static void tt_global_entry_free(struct hlist_node *node, void *arg)
-{
- void *data = container_of(node, struct tt_global_entry, hash_entry);
- kfree(data);
}
static void tt_global_roam_purge(struct bat_priv *bat_priv)
@@ -715,13 +713,14 @@
struct tt_global_entry *tt_global_entry;
struct hlist_node *node, *node_tmp;
struct hlist_head *head;
+ spinlock_t *list_lock; /* protects write access to the hash lists */
int i;
- spin_lock_bh(&bat_priv->tt_ghash_lock);
-
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(tt_global_entry, node, node_tmp,
head, hash_entry) {
if (!(tt_global_entry->flags & TT_CLIENT_ROAM))
@@ -730,20 +729,47 @@
TT_CLIENT_ROAM_TIMEOUT * 1000))
continue;
- _tt_global_del(bat_priv, tt_global_entry,
- "Roaming timeout");
+ bat_dbg(DBG_TT, bat_priv, "Deleting global "
+ "tt entry (%pM): Roaming timeout\n",
+ tt_global_entry->addr);
+ atomic_dec(&tt_global_entry->orig_node->tt_size);
+ hlist_del_rcu(node);
+ tt_global_entry_free_ref(tt_global_entry);
}
+ spin_unlock_bh(list_lock);
}
- spin_unlock_bh(&bat_priv->tt_ghash_lock);
}
static void tt_global_table_free(struct bat_priv *bat_priv)
{
+ struct hashtable_t *hash;
+ spinlock_t *list_lock; /* protects write access to the hash lists */
+ struct tt_global_entry *tt_global_entry;
+ struct hlist_node *node, *node_tmp;
+ struct hlist_head *head;
+ int i;
+
if (!bat_priv->tt_global_hash)
return;
- hash_delete(bat_priv->tt_global_hash, tt_global_entry_free, NULL);
+ hash = bat_priv->tt_global_hash;
+
+ 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(tt_global_entry, node, node_tmp,
+ head, hash_entry) {
+ hlist_del_rcu(node);
+ tt_global_entry_free_ref(tt_global_entry);
+ }
+ spin_unlock_bh(list_lock);
+ }
+
+ hash_destroy(hash);
+
bat_priv->tt_global_hash = NULL;
}
@@ -753,19 +779,19 @@
struct tt_global_entry *tt_global_entry;
struct orig_node *orig_node = NULL;
- spin_lock_bh(&bat_priv->tt_ghash_lock);
tt_global_entry = tt_global_hash_find(bat_priv, addr);
if (!tt_global_entry)
goto out;
if (!atomic_inc_not_zero(&tt_global_entry->orig_node->refcount))
- goto out;
+ goto free_tt;
orig_node = tt_global_entry->orig_node;
+free_tt:
+ tt_global_entry_free_ref(tt_global_entry);
out:
- spin_unlock_bh(&bat_priv->tt_ghash_lock);
return orig_node;
}
@@ -828,7 +854,6 @@
tt_local_entry->addr[j]);
total ^= total_one;
}
-
rcu_read_unlock();
}
@@ -1371,15 +1396,17 @@
bool is_my_client(struct bat_priv *bat_priv, const uint8_t *addr)
{
- struct tt_local_entry *tt_local_entry;
+ struct tt_local_entry *tt_local_entry = NULL;
+ bool ret = false;
- spin_lock_bh(&bat_priv->tt_lhash_lock);
tt_local_entry = tt_local_hash_find(bat_priv, addr);
- spin_unlock_bh(&bat_priv->tt_lhash_lock);
-
+ if (!tt_local_entry)
+ goto out;
+ ret = true;
+out:
if (tt_local_entry)
- return true;
- return false;
+ tt_local_entry_free_ref(tt_local_entry);
+ return ret;
}
void handle_tt_response(struct bat_priv *bat_priv,
@@ -1416,9 +1443,7 @@
spin_unlock_bh(&bat_priv->tt_req_list_lock);
/* Recalculate the CRC for this orig_node and store it */
- spin_lock_bh(&bat_priv->tt_ghash_lock);
orig_node->tt_crc = tt_global_crc(bat_priv, orig_node);
- spin_unlock_bh(&bat_priv->tt_ghash_lock);
/* Roaming phase is over: tables are in sync again. I can
* unset the flag */
orig_node->tt_poss_change = false;