From 7efea60dcffc151870d1abbfccdb1f11cd4b7f21 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Tue, 28 Mar 2017 12:28:28 +0200 Subject: tipc: adjust the policy of holding subscription kref When a new subscription object is inserted into name_seq->subscriptions list, it's under name_seq->lock protection; when a subscription is deleted from the list, it's also under the same lock protection; similarly, when accessing a subscription by going through subscriptions list, the entire process is also protected by the name_seq->lock. Therefore, if subscription refcount is increased before it's inserted into subscriptions list, and its refcount is decreased after it's deleted from the list, it will be unnecessary to hold refcount at all before accessing subscription object which is obtained by going through subscriptions list under name_seq->lock protection. Signed-off-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/name_table.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/tipc/name_table.c') diff --git a/net/tipc/name_table.c b/net/tipc/name_table.c index 9be6592e4a6f..bd0aac87b41a 100644 --- a/net/tipc/name_table.c +++ b/net/tipc/name_table.c @@ -416,6 +416,7 @@ static void tipc_nameseq_subscribe(struct name_seq *nseq, tipc_subscrp_convert_seq(&s->evt.s.seq, s->swap, &ns); + tipc_subscrp_get(s); list_add(&s->nameseq_list, &nseq->subscriptions); if (!sseq) @@ -787,6 +788,7 @@ void tipc_nametbl_unsubscribe(struct tipc_subscription *s) if (seq != NULL) { spin_lock_bh(&seq->lock); list_del_init(&s->nameseq_list); + tipc_subscrp_put(s); if (!seq->first_free && list_empty(&seq->subscriptions)) { hlist_del_init_rcu(&seq->ns_list); kfree(seq->sseqs); -- cgit v1.2.3