The following commit has been merged in the master branch: commit 568cb9eb815fec8efd0349f75e654035813199b6 Author: Marek Lindner lindner_marek@yahoo.de Date: Sun Dec 12 21:57:12 2010 +0000

batman-adv: protect neighbor list with rcu locks

Signed-off-by: Marek Lindner lindner_marek@yahoo.de

diff --git a/originator.c b/originator.c index 1df73e3..4d6d125 100644 --- a/originator.c +++ b/originator.c @@ -67,6 +67,14 @@ void neigh_node_free_ref(struct kref *refcount) kfree(neigh_node); }

+static void neigh_node_free_rcu(struct rcu_head *rcu) +{ + struct neigh_node *neigh_node; + + neigh_node = container_of(rcu, struct neigh_node, rcu); + kref_put(&neigh_node->refcount, neigh_node_free_ref); +} + struct neigh_node *create_neighbor(struct orig_node *orig_node, struct orig_node *orig_neigh_node, uint8_t *neigh, @@ -89,7 +97,9 @@ struct neigh_node *create_neighbor(struct orig_node *orig_node, neigh_node->if_incoming = if_incoming; kref_init(&neigh_node->refcount);

- hlist_add_head(&neigh_node->list, &orig_node->neigh_list); + spin_lock_bh(&orig_node->neigh_list_lock); + hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list); + spin_unlock_bh(&orig_node->neigh_list_lock); return neigh_node; }

@@ -100,13 +110,17 @@ static void free_orig_node(void *data, void *arg) struct orig_node *orig_node = (struct orig_node *)data; struct bat_priv *bat_priv = (struct bat_priv *)arg;

+ spin_lock_bh(&orig_node->neigh_list_lock); + /* for all neighbors towards this originator ... */ hlist_for_each_entry_safe(neigh_node, node, node_tmp, &orig_node->neigh_list, list) { - hlist_del(&neigh_node->list); - kref_put(&neigh_node->refcount, neigh_node_free_ref); + hlist_del_rcu(&neigh_node->list); + call_rcu(&neigh_node->rcu, neigh_node_free_rcu); }

+ spin_unlock_bh(&orig_node->neigh_list_lock); + frag_list_free(&orig_node->frag_list); hna_global_del_orig(bat_priv, orig_node, "originator timed out");

@@ -151,6 +165,7 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr) return NULL;

INIT_HLIST_HEAD(&orig_node->neigh_list); + spin_lock_init(&orig_node->neigh_list_lock);

memcpy(orig_node->orig, addr, ETH_ALEN); orig_node->router = NULL; @@ -200,6 +215,8 @@ static bool purge_orig_neighbors(struct bat_priv *bat_priv,

*best_neigh_node = NULL;

+ spin_lock_bh(&orig_node->neigh_list_lock); + /* for all neighbors towards this originator ... */ hlist_for_each_entry_safe(neigh_node, node, node_tmp, &orig_node->neigh_list, list) { @@ -225,14 +242,16 @@ static bool purge_orig_neighbors(struct bat_priv *bat_priv,

neigh_purged = true;

- hlist_del(&neigh_node->list); - kref_put(&neigh_node->refcount, neigh_node_free_ref); + hlist_del_rcu(&neigh_node->list); + call_rcu(&neigh_node->rcu, neigh_node_free_rcu); } else { if ((*best_neigh_node == NULL) || (neigh_node->tq_avg > (*best_neigh_node)->tq_avg)) *best_neigh_node = neigh_node; } } + + spin_unlock_bh(&orig_node->neigh_list_lock); return neigh_purged; }

@@ -384,11 +403,13 @@ int orig_seq_print_text(struct seq_file *seq, void *offset) neigh_node->addr, neigh_node->if_incoming->net_dev->name);

- hlist_for_each_entry(neigh_node, node, - &orig_node->neigh_list, list) { + 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++; diff --git a/routing.c b/routing.c index 773c1ba..ae383d6 100644 --- a/routing.c +++ b/routing.c @@ -154,14 +154,16 @@ static int is_bidirectional_neigh(struct orig_node *orig_node, unsigned char total_count;

if (orig_node == orig_neigh_node) { - hlist_for_each_entry(tmp_neigh_node, node, - &orig_node->neigh_list, list) { + rcu_read_lock(); + hlist_for_each_entry_rcu(tmp_neigh_node, node, + &orig_node->neigh_list, list) {

if (compare_orig(tmp_neigh_node->addr, orig_neigh_node->orig) && (tmp_neigh_node->if_incoming == if_incoming)) neigh_node = tmp_neigh_node; } + rcu_read_unlock();

if (!neigh_node) neigh_node = create_neighbor(orig_node, @@ -175,14 +177,16 @@ static int is_bidirectional_neigh(struct orig_node *orig_node, neigh_node->last_valid = jiffies; } else { /* find packet count of corresponding one hop neighbor */ - hlist_for_each_entry(tmp_neigh_node, node, - &orig_neigh_node->neigh_list, list) { + rcu_read_lock(); + hlist_for_each_entry_rcu(tmp_neigh_node, node, + &orig_neigh_node->neigh_list, list) {

if (compare_orig(tmp_neigh_node->addr, orig_neigh_node->orig) && (tmp_neigh_node->if_incoming == if_incoming)) neigh_node = tmp_neigh_node; } + rcu_read_unlock();

if (!neigh_node) neigh_node = create_neighbor(orig_neigh_node, @@ -267,8 +271,9 @@ static void update_orig(struct bat_priv *bat_priv, bat_dbg(DBG_BATMAN, bat_priv, "update_originator(): " "Searching and updating originator entry of received packet\n");

- hlist_for_each_entry(tmp_neigh_node, node, - &orig_node->neigh_list, list) { + rcu_read_lock(); + hlist_for_each_entry_rcu(tmp_neigh_node, node, + &orig_node->neigh_list, list) { if (compare_orig(tmp_neigh_node->addr, ethhdr->h_source) && (tmp_neigh_node->if_incoming == if_incoming)) { neigh_node = tmp_neigh_node; @@ -283,6 +288,7 @@ static void update_orig(struct bat_priv *bat_priv, tmp_neigh_node->tq_avg = ring_buffer_avg(tmp_neigh_node->tq_recv); } + rcu_read_unlock();

if (!neigh_node) { struct orig_node *orig_tmp; @@ -411,8 +417,9 @@ static char count_real_packets(struct ethhdr *ethhdr, &orig_node->batman_seqno_reset)) return -1;

- hlist_for_each_entry(tmp_neigh_node, node, - &orig_node->neigh_list, list) { + rcu_read_lock(); + hlist_for_each_entry_rcu(tmp_neigh_node, node, + &orig_node->neigh_list, list) {

is_duplicate |= get_bit_status(tmp_neigh_node->real_bits, orig_node->last_real_seqno, @@ -432,6 +439,7 @@ static char count_real_packets(struct ethhdr *ethhdr, tmp_neigh_node->real_packet_count = bit_packet_count(tmp_neigh_node->real_bits); } + rcu_read_unlock();

if (need_update) { bat_dbg(DBG_BATMAN, bat_priv, @@ -484,15 +492,19 @@ void update_bonding_candidates(struct bat_priv *bat_priv, * as "bonding partner" */

/* first, zero the list */ - hlist_for_each_entry(tmp_neigh_node, node, - &orig_node->neigh_list, list) { + rcu_read_lock(); + hlist_for_each_entry_rcu(tmp_neigh_node, node, + &orig_node->neigh_list, list) { tmp_neigh_node->next_bond_candidate = NULL; } + rcu_read_unlock();

first_candidate = NULL; last_candidate = NULL; - hlist_for_each_entry(tmp_neigh_node, node, - &orig_node->neigh_list, list) { + + rcu_read_lock(); + hlist_for_each_entry_rcu(tmp_neigh_node, node, + &orig_node->neigh_list, list) {

/* only consider if it has the same primary address ... */ if (memcmp(orig_node->orig, @@ -509,8 +521,8 @@ void update_bonding_candidates(struct bat_priv *bat_priv, * select this candidate because of possible interference. */

interference_candidate = 0; - hlist_for_each_entry(tmp_neigh_node2, node2, - &orig_node->neigh_list, list) { + hlist_for_each_entry_rcu(tmp_neigh_node2, node2, + &orig_node->neigh_list, list) {

if (tmp_neigh_node2 == tmp_neigh_node) continue; @@ -544,6 +556,7 @@ void update_bonding_candidates(struct bat_priv *bat_priv,

candidates++; } + rcu_read_unlock();

if (candidates > 0) { first_candidate->next_bond_candidate = last_candidate; diff --git a/types.h b/types.h index 1ce91f6..1d6365d 100644 --- a/types.h +++ b/types.h @@ -85,6 +85,7 @@ struct orig_node { uint32_t last_bcast_seqno; struct hlist_head neigh_list; struct list_head frag_list; + spinlock_t neigh_list_lock; /* protects neighbor list */ unsigned long last_frag_packet; struct { uint8_t candidates; @@ -116,6 +117,7 @@ struct neigh_node { unsigned long last_valid; TYPE_OF_WORD real_bits[NUM_WORDS]; struct kref refcount; + struct rcu_head rcu; struct orig_node *orig_node; struct batman_if *if_incoming; };