/*
- * Copyright (C) 2009-2010 B.A.T.M.A.N. contributors:
+ * Copyright (C) 2009-2011 B.A.T.M.A.N. contributors:
*
* Marek Lindner
*
#include <linux/udp.h>
#include <linux/if_vlan.h>
-static void gw_node_free_ref(struct kref *refcount)
+static void gw_node_free_rcu(struct rcu_head *rcu)
{
struct gw_node *gw_node;
- gw_node = container_of(refcount, struct gw_node, refcount);
+ gw_node = container_of(rcu, struct gw_node, rcu);
kfree(gw_node);
}
-static void gw_node_free_rcu(struct rcu_head *rcu)
+static void gw_node_free_ref(struct gw_node *gw_node)
{
- struct gw_node *gw_node;
-
- gw_node = container_of(rcu, struct gw_node, rcu);
- kref_put(&gw_node->refcount, gw_node_free_ref);
+ if (atomic_dec_and_test(&gw_node->refcount))
+ call_rcu(&gw_node->rcu, gw_node_free_rcu);
}
void *gw_get_selected(struct bat_priv *bat_priv)
{
- struct gw_node *curr_gateway_tmp = bat_priv->curr_gw;
+ struct gw_node *curr_gateway_tmp;
+ struct orig_node *orig_node = NULL;
+ rcu_read_lock();
+ curr_gateway_tmp = rcu_dereference(bat_priv->curr_gw);
if (!curr_gateway_tmp)
- return NULL;
+ goto out;
+
+ orig_node = curr_gateway_tmp->orig_node;
- return curr_gateway_tmp->orig_node;
+ if (orig_node)
+ kref_get(&orig_node->refcount);
+
+out:
+ rcu_read_unlock();
+ return orig_node;
}
void gw_deselect(struct bat_priv *bat_priv)
{
- struct gw_node *gw_node = bat_priv->curr_gw;
+ struct gw_node *gw_node;
- bat_priv->curr_gw = NULL;
+ spin_lock_bh(&bat_priv->gw_list_lock);
+ gw_node = rcu_dereference(bat_priv->curr_gw);
+ rcu_assign_pointer(bat_priv->curr_gw, NULL);
+ spin_unlock_bh(&bat_priv->gw_list_lock);
if (gw_node)
- kref_put(&gw_node->refcount, gw_node_free_ref);
+ gw_node_free_ref(gw_node);
}
-static struct gw_node *gw_select(struct bat_priv *bat_priv,
- struct gw_node *new_gw_node)
+static void gw_select(struct bat_priv *bat_priv, struct gw_node *new_gw_node)
{
- struct gw_node *curr_gw_node = bat_priv->curr_gw;
+ struct gw_node *curr_gw_node;
- if (new_gw_node)
- kref_get(&new_gw_node->refcount);
+ if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
+ new_gw_node = NULL;
+
+ spin_lock_bh(&bat_priv->gw_list_lock);
+ curr_gw_node = rcu_dereference(bat_priv->curr_gw);
+ rcu_assign_pointer(bat_priv->curr_gw, new_gw_node);
+ spin_unlock_bh(&bat_priv->gw_list_lock);
- bat_priv->curr_gw = new_gw_node;
- return curr_gw_node;
+ if (curr_gw_node)
+ gw_node_free_ref(curr_gw_node);
}
void gw_election(struct bat_priv *bat_priv)
{
struct hlist_node *node;
- struct gw_node *gw_node, *curr_gw_tmp = NULL, *old_gw_node = NULL;
+ struct gw_node *gw_node, *curr_gw, *curr_gw_tmp = NULL;
uint8_t max_tq = 0;
uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
int down, up;
if (atomic_read(&bat_priv->gw_mode) != GW_MODE_CLIENT)
return;
- if (bat_priv->curr_gw)
+ rcu_read_lock();
+ curr_gw = rcu_dereference(bat_priv->curr_gw);
+ if (curr_gw) {
+ rcu_read_unlock();
return;
+ }
- rcu_read_lock();
if (hlist_empty(&bat_priv->gw_list)) {
- rcu_read_unlock();
- if (bat_priv->curr_gw) {
+ if (curr_gw) {
+ rcu_read_unlock();
bat_dbg(DBG_BATMAN, bat_priv,
"Removing selected gateway - "
"no gateway in range\n");
gw_deselect(bat_priv);
- }
+ } else
+ rcu_read_unlock();
return;
}
max_gw_factor = tmp_gw_factor;
}
- if (bat_priv->curr_gw != curr_gw_tmp) {
- if ((bat_priv->curr_gw) && (!curr_gw_tmp))
+ if (curr_gw != curr_gw_tmp) {
+ if ((curr_gw) && (!curr_gw_tmp))
bat_dbg(DBG_BATMAN, bat_priv,
"Removing selected gateway - "
"no gateway in range\n");
- else if ((!bat_priv->curr_gw) && (curr_gw_tmp))
+ else if ((!curr_gw) && (curr_gw_tmp))
bat_dbg(DBG_BATMAN, bat_priv,
"Adding route to gateway %pM "
"(gw_flags: %i, tq: %i)\n",
curr_gw_tmp->orig_node->gw_flags,
curr_gw_tmp->orig_node->router->tq_avg);
- old_gw_node = gw_select(bat_priv, curr_gw_tmp);
+ gw_select(bat_priv, curr_gw_tmp);
}
rcu_read_unlock();
-
- /* the kfree() has to be outside of the rcu lock */
- if (old_gw_node)
- kref_put(&old_gw_node->refcount, gw_node_free_ref);
}
void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
{
- struct gw_node *curr_gateway_tmp = bat_priv->curr_gw;
+ struct gw_node *curr_gateway_tmp;
uint8_t gw_tq_avg, orig_tq_avg;
+ rcu_read_lock();
+ curr_gateway_tmp = rcu_dereference(bat_priv->curr_gw);
if (!curr_gateway_tmp)
- return;
+ goto out_rcu;
if (!curr_gateway_tmp->orig_node)
- goto deselect;
+ goto deselect_rcu;
if (!curr_gateway_tmp->orig_node->router)
- goto deselect;
+ goto deselect_rcu;
/* this node already is the gateway */
if (curr_gateway_tmp->orig_node == orig_node)
- return;
+ goto out_rcu;
if (!orig_node->router)
- return;
+ goto out_rcu;
gw_tq_avg = curr_gateway_tmp->orig_node->router->tq_avg;
+ rcu_read_unlock();
+
orig_tq_avg = orig_node->router->tq_avg;
/* the TQ value has to be better */
if (orig_tq_avg < gw_tq_avg)
- return;
+ goto out;
/**
* if the routing class is greater than 3 the value tells us how much
**/
if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
(orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
- return;
+ goto out;
bat_dbg(DBG_BATMAN, bat_priv,
"Restarting gateway selection: better gateway found (tq curr: "
"%i, tq new: %i)\n",
gw_tq_avg, orig_tq_avg);
+ goto deselect;
+out_rcu:
+ rcu_read_unlock();
+ goto out;
+deselect_rcu:
+ rcu_read_unlock();
deselect:
gw_deselect(bat_priv);
+out:
+ return;
}
static void gw_node_add(struct bat_priv *bat_priv,
memset(gw_node, 0, sizeof(struct gw_node));
INIT_HLIST_NODE(&gw_node->list);
gw_node->orig_node = orig_node;
- kref_init(&gw_node->refcount);
+ atomic_set(&gw_node->refcount, 1);
spin_lock_bh(&bat_priv->gw_list_lock);
hlist_add_head_rcu(&gw_node->list, &bat_priv->gw_list);
"Gateway %pM removed from gateway list\n",
orig_node->orig);
- if (gw_node == bat_priv->curr_gw) {
+ if (gw_node == rcu_dereference(bat_priv->curr_gw)) {
rcu_read_unlock();
gw_deselect(bat_priv);
return;
atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE)
continue;
- if (bat_priv->curr_gw == gw_node)
+ if (rcu_dereference(bat_priv->curr_gw) == gw_node)
gw_deselect(bat_priv);
hlist_del_rcu(&gw_node->list);
- call_rcu(&gw_node->rcu, gw_node_free_rcu);
+ gw_node_free_ref(gw_node);
}
static int _write_buffer_text(struct bat_priv *bat_priv,
struct seq_file *seq, struct gw_node *gw_node)
{
- int down, up;
+ struct gw_node *curr_gw;
+ int down, up, ret;
gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
- return seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
- (bat_priv->curr_gw == gw_node ? "=>" : " "),
+ rcu_read_lock();
+ curr_gw = rcu_dereference(bat_priv->curr_gw);
+
+ ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
+ (curr_gw == gw_node ? "=>" : " "),
gw_node->orig_node->orig,
gw_node->orig_node->router->tq_avg,
gw_node->orig_node->router->addr,
(down > 2048 ? "MBit" : "KBit"),
(up > 2048 ? up / 1024 : up),
(up > 2048 ? "MBit" : "KBit"));
+
+ rcu_read_unlock();
+ return ret;
}
int gw_client_seq_print_text(struct seq_file *seq, void *offset)
if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)
return -1;
- if (!bat_priv->curr_gw)
+ rcu_read_lock();
+ if (!rcu_dereference(bat_priv->curr_gw)) {
+ rcu_read_unlock();
return 0;
+ }
+ rcu_read_unlock();
return 1;
}
projects / deliverable / linux.git / blobdiff