diff options
Diffstat (limited to 'net/tipc/subscr.c')
| -rw-r--r-- | net/tipc/subscr.c | 120 |
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; } |