From 139bb36f754adbf6d3c836db09d6459e25167b38 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Tue, 28 Mar 2017 12:28:27 +0200 Subject: [PATCH] tipc: advance the time of deleting subscription from subscriber->subscrp_list After a subscription object is created, it's inserted into its subscriber subscrp_list list under subscriber lock protection, similarly, before it's destroyed, it should be first removed from its subscriber->subscrp_list. Since the subscription list is accessed with subscriber lock, all the subscriptions are valid during the lock duration. Hence in tipc_subscrb_subscrp_delete(), we remove subscription get/put and the extra subscriber unlock/lock. After this change, the subscriptions refcount cleanup is very simple and does not access any lock. Acked-by: Jon Maloy Signed-off-by: Ying Xue Signed-off-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller --- net/tipc/subscr.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c index 271cd66e4b3b..0649bc29c6bb 100644 --- a/net/tipc/subscr.c +++ b/net/tipc/subscr.c @@ -145,6 +145,7 @@ static void tipc_subscrp_timeout(unsigned long data) spin_lock_bh(&subscriber->lock); tipc_nametbl_unsubscribe(sub); + list_del(&sub->subscrp_list); spin_unlock_bh(&subscriber->lock); /* Notify subscriber of timeout */ @@ -177,10 +178,7 @@ static void tipc_subscrp_kref_release(struct kref *kref) struct tipc_net *tn = net_generic(sub->net, tipc_net_id); struct tipc_subscriber *subscriber = sub->subscriber; - spin_lock_bh(&subscriber->lock); - list_del(&sub->subscrp_list); atomic_dec(&tn->subscription_count); - spin_unlock_bh(&subscriber->lock); kfree(sub); tipc_subscrb_put(subscriber); } @@ -210,11 +208,8 @@ static void tipc_subscrb_subscrp_delete(struct tipc_subscriber *subscriber, continue; tipc_nametbl_unsubscribe(sub); - tipc_subscrp_get(sub); - spin_unlock_bh(&subscriber->lock); + list_del(&sub->subscrp_list); tipc_subscrp_delete(sub); - tipc_subscrp_put(sub); - spin_lock_bh(&subscriber->lock); if (s) break; -- GitLab