From: Simon Wunderlich <simon.wunderlich@s2003.tu-chemnitz.de>
To: The list for a Better Approach To Mobile Ad-hoc Networking
<b.a.t.m.a.n@lists.open-mesh.org>
Subject: [B.A.T.M.A.N.] [PATCH] batman-adv: protect bonding with rcu locks
Date: Thu, 30 Dec 2010 03:09:17 +0100 [thread overview]
Message-ID: <20101230020917.GA4707@pandem0nium> (raw)
In-Reply-To: <201012130118.14949.lindner_marek@yahoo.de>
bonding / alternating candidates need to be secured by rcu locks
as well. This patch therefore converts the bonding list
from a plain pointer list to a rcu securable lists and references
the bonding candidates.
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
---
originator.c | 17 +++++++-
routing.c | 140 +++++++++++++++++++++++++++++++++-------------------------
types.h | 4 +-
unicast.c | 9 +---
4 files changed, 100 insertions(+), 70 deletions(-)
diff --git a/batman-adv/originator.c b/batman-adv/originator.c
index 899ab0b..3e18488 100644
--- a/batman-adv/originator.c
+++ b/batman-adv/originator.c
@@ -88,6 +88,7 @@ struct neigh_node *create_neighbor(struct orig_node *orig_node,
return NULL;
INIT_HLIST_NODE(&neigh_node->list);
+ INIT_LIST_HEAD(&neigh_node->bonding_list);
memcpy(neigh_node->addr, neigh, ETH_ALEN);
neigh_node->orig_node = orig_neigh_node;
@@ -103,13 +104,20 @@ struct neigh_node *create_neighbor(struct orig_node *orig_node,
void orig_node_free_ref(struct kref *refcount)
{
struct hlist_node *node, *node_tmp;
- struct neigh_node *neigh_node;
+ struct neigh_node *neigh_node, *tmp_neigh_node;
struct orig_node *orig_node;
orig_node = container_of(refcount, struct orig_node, refcount);
spin_lock_bh(&orig_node->neigh_list_lock);
+ /* for all bonding members ... */
+ list_for_each_entry_safe(neigh_node, tmp_neigh_node,
+ &orig_node->bond.selected, bonding_list) {
+ list_del_rcu(&neigh_node->bonding_list);
+ call_rcu(&neigh_node->rcu, neigh_node_free_rcu);
+ }
+
/* for all neighbors towards this originator ... */
hlist_for_each_entry_safe(neigh_node, node, node_tmp,
&orig_node->neigh_list, list) {
@@ -202,6 +210,7 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
return NULL;
INIT_HLIST_HEAD(&orig_node->neigh_list);
+ INIT_LIST_HEAD(&orig_node->bond.selected);
spin_lock_init(&orig_node->ogm_cnt_lock);
spin_lock_init(&orig_node->neigh_list_lock);
kref_init(&orig_node->refcount);
@@ -285,6 +294,12 @@ static bool purge_orig_neighbors(struct bat_priv *bat_priv,
neigh_purged = true;
hlist_del_rcu(&neigh_node->list);
+
+ if (!list_empty(&neigh_node->bonding_list)) {
+ orig_node->bond.candidates--;
+ list_del_rcu(&neigh_node->bonding_list);
+ call_rcu(&neigh_node->rcu, neigh_node_free_rcu);
+ }
call_rcu(&neigh_node->rcu, neigh_node_free_rcu);
} else {
if ((!*best_neigh_node) ||
diff --git a/batman-adv/routing.c b/batman-adv/routing.c
index 557e7d7..ad8d237 100644
--- a/batman-adv/routing.c
+++ b/batman-adv/routing.c
@@ -517,7 +517,6 @@ void update_bonding_candidates(struct bat_priv *bat_priv,
int best_tq;
struct hlist_node *node, *node2;
struct neigh_node *tmp_neigh_node, *tmp_neigh_node2;
- struct neigh_node *first_candidate, *last_candidate;
/* update the candidates for this originator */
if (!orig_node->router) {
@@ -525,6 +524,7 @@ void update_bonding_candidates(struct bat_priv *bat_priv,
return;
}
+ spin_lock_bh(&orig_node->neigh_list_lock);
best_tq = orig_node->router->tq_avg;
/* update bond.candidates */
@@ -535,19 +535,14 @@ void update_bonding_candidates(struct bat_priv *bat_priv,
* as "bonding partner" */
/* first, zero the 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;
+ list_for_each_entry_safe(tmp_neigh_node, tmp_neigh_node2,
+ &orig_node->bond.selected, bonding_list) {
+ list_del_rcu(&tmp_neigh_node->bonding_list);
+ kref_put(&tmp_neigh_node->refcount, neigh_node_free_ref);
}
- rcu_read_unlock();
- first_candidate = NULL;
- last_candidate = NULL;
-
- rcu_read_lock();
hlist_for_each_entry_rcu(tmp_neigh_node, node,
- &orig_node->neigh_list, list) {
+ &orig_node->neigh_list, list) {
/* only consider if it has the same primary address ... */
if (memcmp(orig_node->orig,
@@ -572,7 +567,7 @@ void update_bonding_candidates(struct bat_priv *bat_priv,
/* we only care if the other candidate is even
* considered as candidate. */
- if (!tmp_neigh_node2->next_bond_candidate)
+ if (!list_empty(&tmp_neigh_node2->bonding_list))
continue;
@@ -589,24 +584,16 @@ void update_bonding_candidates(struct bat_priv *bat_priv,
if (interference_candidate)
continue;
- if (!first_candidate) {
- first_candidate = tmp_neigh_node;
- tmp_neigh_node->next_bond_candidate = first_candidate;
- } else
- tmp_neigh_node->next_bond_candidate = last_candidate;
-
- last_candidate = tmp_neigh_node;
+ list_add_rcu(&tmp_neigh_node->bonding_list,
+ &orig_node->bond.selected);
+ kref_get(&tmp_neigh_node->refcount);
candidates++;
}
- rcu_read_unlock();
-
- if (candidates > 0) {
- first_candidate->next_bond_candidate = last_candidate;
- orig_node->bond.selected = first_candidate;
- }
-
orig_node->bond.candidates = candidates;
+
+ spin_unlock_bh(&orig_node->neigh_list_lock);
+
}
void receive_bat_packet(struct ethhdr *ethhdr,
@@ -1110,16 +1097,18 @@ out:
}
/* find a suitable router for this originator, and use
- * bonding if possible. */
+ * bonding if possible. increases the found neighbors
+ * refcount.*/
struct neigh_node *find_router(struct bat_priv *bat_priv,
struct orig_node *orig_node,
struct batman_if *recv_if)
{
struct orig_node *primary_orig_node;
struct orig_node *router_orig;
- struct neigh_node *router, *first_candidate, *best_router;
+ struct neigh_node *router, *first_candidate, *tmp_neigh_node;
static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
int bonding_enabled;
+ int best_router_tq;
if (!orig_node)
return NULL;
@@ -1132,15 +1121,23 @@ struct neigh_node *find_router(struct bat_priv *bat_priv,
bonding_enabled = atomic_read(&bat_priv->bonding);
- if ((!recv_if) && (!bonding_enabled))
- return orig_node->router;
-
+ rcu_read_lock();
+ /* select default router to output */
+ router = orig_node->router;
router_orig = orig_node->router->orig_node;
+ if (!router_orig) {
+ rcu_read_unlock();
+ return NULL;
+ }
+
+
+ if ((!recv_if) && (!bonding_enabled))
+ goto return_router;
/* if we have something in the primary_addr, we can search
* for a potential bonding candidate. */
if (memcmp(router_orig->primary_addr, zero_mac, ETH_ALEN) == 0)
- return orig_node->router;
+ goto return_router;
/* find the orig_node which has the primary interface. might
* even be the same as our router_orig in many cases */
@@ -1149,60 +1146,83 @@ 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;
+ goto return_router;
}
-
/* with less than 2 candidates, we can't do any
* bonding and prefer the original router. */
if (primary_orig_node->bond.candidates < 2)
- return orig_node->router;
+ goto return_router;
/* all nodes between should choose a candidate which
* is is not on the interface where the packet came
* in. */
- first_candidate = primary_orig_node->bond.selected;
- router = first_candidate;
+
+ first_candidate = NULL;
+ router = NULL;
if (bonding_enabled) {
/* in the bonding case, send the packets in a round
* robin fashion over the remaining interfaces. */
- do {
+
+ list_for_each_entry_rcu(tmp_neigh_node,
+ &primary_orig_node->bond.selected, bonding_list) {
+ if (!first_candidate)
+ first_candidate = tmp_neigh_node;
/* recv_if == NULL on the first node. */
- if (router->if_incoming != recv_if)
+ if (tmp_neigh_node->if_incoming != recv_if) {
+ router = tmp_neigh_node;
break;
+ }
+ }
- router = router->next_bond_candidate;
- } while (router != first_candidate);
+ /* use the first candidate if nothing was found. */
+ if (!router)
+ router = first_candidate;
- primary_orig_node->bond.selected = router->next_bond_candidate;
+ /* selected should point to the next element
+ * after the current router */
+ spin_lock_bh(&primary_orig_node->neigh_list_lock);
+ /* this is a list_move(), which unfortunately
+ * does not exist as rcu version */
+ list_del_rcu(&primary_orig_node->bond.selected);
+ list_add_rcu(&primary_orig_node->bond.selected,
+ &router->bonding_list);
+ spin_unlock_bh(&primary_orig_node->neigh_list_lock);
} else {
/* if bonding is disabled, use the best of the
* remaining candidates which are not using
* this interface. */
- best_router = first_candidate;
+ best_router_tq = 0;
+ list_for_each_entry_rcu(tmp_neigh_node,
+ &primary_orig_node->bond.selected, bonding_list) {
+ if (!first_candidate)
+ first_candidate = tmp_neigh_node;
- do {
/* recv_if == NULL on the first node. */
- if ((router->if_incoming != recv_if) &&
- (router->tq_avg > best_router->tq_avg))
- best_router = router;
+ if (tmp_neigh_node->if_incoming != recv_if)
+ /* if we don't have a router yet
+ * or this one is better, choose it. */
+ if ((!router) ||
+ (tmp_neigh_node->tq_avg > router->tq_avg)) {
+ router = tmp_neigh_node;
+ best_router_tq = 0;
+ }
+ }
- router = router->next_bond_candidate;
- } while (router != first_candidate);
-
- router = best_router;
+ /* use the first candidate if nothing was found. */
+ if (!router)
+ router = first_candidate;
}
-
+return_router:
+ kref_get(&router->refcount);
+ rcu_read_unlock();
return router;
}
@@ -1210,7 +1230,7 @@ static int check_unicast_packet(struct sk_buff *skb, int hdr_size)
{
struct ethhdr *ethhdr;
- /* drop packet if it has not necessary minimum size */
+/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, hdr_size)))
return -1;
@@ -1262,13 +1282,13 @@ int route_unicast_packet(struct sk_buff *skb, struct batman_if *recv_if,
goto unlock;
kref_get(&orig_node->refcount);
+ rcu_read_unlock();
+
+ /* find_router() increases neigh_nodes refcount if found. */
neigh_node = find_router(bat_priv, orig_node, recv_if);
if (!neigh_node)
- goto unlock;
-
- kref_get(&neigh_node->refcount);
- rcu_read_unlock();
+ goto out;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
diff --git a/batman-adv/types.h b/batman-adv/types.h
index 52b6b08..8264050 100644
--- a/batman-adv/types.h
+++ b/batman-adv/types.h
@@ -92,7 +92,7 @@ struct orig_node {
spinlock_t ogm_cnt_lock; /* protects ogm counter */
struct {
uint8_t candidates;
- struct neigh_node *selected;
+ struct list_head selected;
} bond;
};
@@ -116,7 +116,7 @@ struct neigh_node {
uint8_t tq_index;
uint8_t tq_avg;
uint8_t last_ttl;
- struct neigh_node *next_bond_candidate;
+ struct list_head bonding_list;
unsigned long last_valid;
unsigned long real_bits[NUM_WORDS];
struct kref refcount;
diff --git a/batman-adv/unicast.c b/batman-adv/unicast.c
index 67bed2d..cfe08dd 100644
--- a/batman-adv/unicast.c
+++ b/batman-adv/unicast.c
@@ -314,14 +314,11 @@ trans_search:
orig_node = transtable_search(bat_priv, ethhdr->h_dest);
find_router:
- rcu_read_lock();
+ /* find_router() increases neigh_nodes refcount if found. */
neigh_node = find_router(bat_priv, orig_node, NULL);
if (!neigh_node)
- goto unlock;
-
- kref_get(&neigh_node->refcount);
- rcu_read_unlock();
+ goto out;
if (neigh_node->if_incoming->if_status != IF_ACTIVE)
goto out;
@@ -353,8 +350,6 @@ find_router:
ret = 0;
goto out;
-unlock:
- rcu_read_unlock();
out:
if (neigh_node)
kref_put(&neigh_node->refcount, neigh_node_free_ref);
--
1.7.2.3
next prev parent reply other threads:[~2010-12-30 2:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-13 0:18 [B.A.T.M.A.N.] performance patches (v3) Marek Lindner
2010-12-13 0:18 ` [B.A.T.M.A.N.] [PATCH 1/5] batman-adv: protect neigh_nodes used outside of rcu_locks with refcounting Marek Lindner
2010-12-13 0:18 ` [B.A.T.M.A.N.] [PATCH 2/5] batman-adv: protect each hash row with rcu locks Marek Lindner
2010-12-13 0:18 ` [B.A.T.M.A.N.] [PATCH 3/5] batman-adv: protect originator nodes with reference counters Marek Lindner
2010-12-13 0:18 ` [B.A.T.M.A.N.] [PATCH 4/5] batman-adv: protect ogm counter arrays with spinlock Marek Lindner
2010-12-13 0:18 ` [B.A.T.M.A.N.] [PATCH 5/5] batman-adv: remove orig_hash spinlock Marek Lindner
2010-12-30 2:09 ` Simon Wunderlich [this message]
2011-01-16 11:35 ` [B.A.T.M.A.N.] [PATCH] batman-adv: protect bonding with rcu locks Marek Lindner
2011-01-16 11:36 ` [B.A.T.M.A.N.] [PATCH] batman-adv: protect bonding with rcu locks (proposal) Marek Lindner
2011-01-16 17:07 ` [B.A.T.M.A.N.] [PATCH] batman-adv: protect bonding with rcu locks Simon Wunderlich
2011-01-19 20:07 ` [B.A.T.M.A.N.] performance patches (v3) Marek Lindner
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