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Diffstat (limited to 'net/tipc/subscr.c')
-rw-r--r--net/tipc/subscr.c120
1 files changed, 52 insertions, 68 deletions
diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
index d0dbde420540..9b24c9c7e05a 100644
--- a/net/tipc/subscr.c
+++ b/net/tipc/subscr.c
@@ -40,16 +40,21 @@
/**
* struct tipc_subscriber - TIPC network topology subscriber
+ * @kref: reference counter to tipc_subscription object
* @conid: connection identifier to server connecting to subscriber
* @lock: control access to subscriber
* @subscrp_list: list of subscription objects for this subscriber
*/
struct tipc_subscriber {
+ struct kref kref;
int conid;
spinlock_t lock;
struct list_head subscrp_list;
};
+static void tipc_subscrp_delete(struct tipc_subscription *sub);
+static void tipc_subscrb_put(struct tipc_subscriber *subscriber);
+
/**
* htohl - convert value to endianness used by destination
* @in: value to convert
@@ -116,42 +121,34 @@ static void tipc_subscrp_timeout(unsigned long data)
{
struct tipc_subscription *sub = (struct tipc_subscription *)data;
struct tipc_subscriber *subscriber = sub->subscriber;
- struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
-
- /* The spin lock per subscriber is used to protect its members */
- spin_lock_bh(&subscriber->lock);
-
- /* Validate timeout (in case subscription is being cancelled) */
- if (sub->timeout == TIPC_WAIT_FOREVER) {
- spin_unlock_bh(&subscriber->lock);
- return;
- }
-
- /* Unlink subscription from name table */
- tipc_nametbl_unsubscribe(sub);
-
- /* Unlink subscription from subscriber */
- list_del(&sub->subscrp_list);
-
- spin_unlock_bh(&subscriber->lock);
/* Notify subscriber of timeout */
tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
TIPC_SUBSCR_TIMEOUT, 0, 0);
- /* Now destroy subscription */
- kfree(sub);
- atomic_dec(&tn->subscription_count);
+ spin_lock_bh(&subscriber->lock);
+ tipc_subscrp_delete(sub);
+ spin_unlock_bh(&subscriber->lock);
+
+ tipc_subscrb_put(subscriber);
}
-static void tipc_subscrp_delete(struct tipc_subscription *sub)
+static void tipc_subscrb_kref_release(struct kref *kref)
{
- struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
+ struct tipc_subscriber *subcriber = container_of(kref,
+ struct tipc_subscriber, kref);
- tipc_nametbl_unsubscribe(sub);
- list_del(&sub->subscrp_list);
- kfree(sub);
- atomic_dec(&tn->subscription_count);
+ kfree(subcriber);
+}
+
+static void tipc_subscrb_put(struct tipc_subscriber *subscriber)
+{
+ kref_put(&subscriber->kref, tipc_subscrb_kref_release);
+}
+
+static void tipc_subscrb_get(struct tipc_subscriber *subscriber)
+{
+ kref_get(&subscriber->kref);
}
static struct tipc_subscriber *tipc_subscrb_create(int conid)
@@ -163,6 +160,7 @@ static struct tipc_subscriber *tipc_subscrb_create(int conid)
pr_warn("Subscriber rejected, no memory\n");
return NULL;
}
+ kref_init(&subscriber->kref);
INIT_LIST_HEAD(&subscriber->subscrp_list);
subscriber->conid = conid;
spin_lock_init(&subscriber->lock);
@@ -172,62 +170,48 @@ static struct tipc_subscriber *tipc_subscrb_create(int conid)
static void tipc_subscrb_delete(struct tipc_subscriber *subscriber)
{
- struct tipc_subscription *sub;
- struct tipc_subscription *sub_temp;
+ struct tipc_subscription *sub, *temp;
spin_lock_bh(&subscriber->lock);
-
/* Destroy any existing subscriptions for subscriber */
- list_for_each_entry_safe(sub, sub_temp, &subscriber->subscrp_list,
+ list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
subscrp_list) {
- if (sub->timeout != TIPC_WAIT_FOREVER) {
- spin_unlock_bh(&subscriber->lock);
- del_timer_sync(&sub->timer);
- spin_lock_bh(&subscriber->lock);
+ if (del_timer(&sub->timer)) {
+ tipc_subscrp_delete(sub);
+ tipc_subscrb_put(subscriber);
}
- tipc_subscrp_delete(sub);
}
spin_unlock_bh(&subscriber->lock);
- /* Now destroy subscriber */
- kfree(subscriber);
+ tipc_subscrb_put(subscriber);
+}
+
+static void tipc_subscrp_delete(struct tipc_subscription *sub)
+{
+ struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
+
+ tipc_nametbl_unsubscribe(sub);
+ list_del(&sub->subscrp_list);
+ kfree(sub);
+ atomic_dec(&tn->subscription_count);
}
-/**
- * tipc_subscrp_cancel - handle subscription cancellation request
- *
- * Called with subscriber lock held. Routine must temporarily release lock
- * to enable the subscription timeout routine to finish without deadlocking;
- * the lock is then reclaimed to allow caller to release it upon return.
- *
- * Note that fields of 's' use subscriber's endianness!
- */
static void tipc_subscrp_cancel(struct tipc_subscr *s,
struct tipc_subscriber *subscriber)
{
- struct tipc_subscription *sub;
- struct tipc_subscription *sub_temp;
- int found = 0;
+ struct tipc_subscription *sub, *temp;
/* Find first matching subscription, exit if not found */
- list_for_each_entry_safe(sub, sub_temp, &subscriber->subscrp_list,
+ list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
subscrp_list) {
if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
- found = 1;
+ if (del_timer(&sub->timer)) {
+ tipc_subscrp_delete(sub);
+ tipc_subscrb_put(subscriber);
+ }
break;
}
}
- if (!found)
- return;
-
- /* Cancel subscription timer (if used), then delete subscription */
- if (sub->timeout != TIPC_WAIT_FOREVER) {
- sub->timeout = TIPC_WAIT_FOREVER;
- spin_unlock_bh(&subscriber->lock);
- del_timer_sync(&sub->timer);
- spin_lock_bh(&subscriber->lock);
- }
- tipc_subscrp_delete(sub);
}
static int tipc_subscrp_create(struct net *net, struct tipc_subscr *s,
@@ -281,11 +265,11 @@ static int tipc_subscrp_create(struct net *net, struct tipc_subscr *s,
sub->swap = swap;
memcpy(&sub->evt.s, s, sizeof(*s));
atomic_inc(&tn->subscription_count);
- if (sub->timeout != TIPC_WAIT_FOREVER) {
- setup_timer(&sub->timer, tipc_subscrp_timeout,
- (unsigned long)sub);
- mod_timer(&sub->timer, jiffies + sub->timeout);
- }
+ setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub);
+ if (sub->timeout != TIPC_WAIT_FOREVER)
+ sub->timeout += jiffies;
+ if (!mod_timer(&sub->timer, sub->timeout))
+ tipc_subscrb_get(subscriber);
*sub_p = sub;
return 0;
}