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| author | Ying Xue | 2017-03-28 12:28:28 +0200 |
|---|---|---|
| committer | David S. Miller | 2017-03-29 03:03:33 +0200 |
| commit | 7efea60dcffc151870d1abbfccdb1f11cd4b7f21 (patch) | |
| tree | 17bdb6c1fe9c4a204421de23f7f347073b868deb /net/tipc/name_table.c | |
| parent | tipc: advance the time of deleting subscription from subscriber->subscrp_list (diff) | |
| download | kernel-qcow2-linux-7efea60dcffc151870d1abbfccdb1f11cd4b7f21.tar.gz kernel-qcow2-linux-7efea60dcffc151870d1abbfccdb1f11cd4b7f21.tar.xz kernel-qcow2-linux-7efea60dcffc151870d1abbfccdb1f11cd4b7f21.zip | |
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 <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc/name_table.c')
| -rw-r--r-- | net/tipc/name_table.c | 2 |
1 files changed, 2 insertions, 0 deletions
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); |