diff options
Diffstat (limited to 'net/sched/act_api.c')
| -rw-r--r-- | net/sched/act_api.c | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/net/sched/act_api.c b/net/sched/act_api.c index 02670c7489e3..4f064ecab882 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -105,14 +105,26 @@ int __tcf_idr_release(struct tc_action *p, bool bind, bool strict) ASSERT_RTNL(); + /* Release with strict==1 and bind==0 is only called through act API + * interface (classifiers always bind). Only case when action with + * positive reference count and zero bind count can exist is when it was + * also created with act API (unbinding last classifier will destroy the + * action if it was created by classifier). So only case when bind count + * can be changed after initial check is when unbound action is + * destroyed by act API while classifier binds to action with same id + * concurrently. This result either creation of new action(same behavior + * as before), or reusing existing action if concurrent process + * increments reference count before action is deleted. Both scenarios + * are acceptable. + */ if (p) { if (bind) - p->tcfa_bindcnt--; - else if (strict && p->tcfa_bindcnt > 0) + atomic_dec(&p->tcfa_bindcnt); + else if (strict && atomic_read(&p->tcfa_bindcnt) > 0) return -EPERM; - p->tcfa_refcnt--; - if (p->tcfa_bindcnt <= 0 && p->tcfa_refcnt <= 0) { + if (atomic_read(&p->tcfa_bindcnt) <= 0 && + refcount_dec_and_test(&p->tcfa_refcnt)) { if (p->ops->cleanup) p->ops->cleanup(p); tcf_idr_remove(p->idrinfo, p); @@ -304,8 +316,8 @@ bool tcf_idr_check(struct tc_action_net *tn, u32 index, struct tc_action **a, if (index && p) { if (bind) - p->tcfa_bindcnt++; - p->tcfa_refcnt++; + atomic_inc(&p->tcfa_bindcnt); + refcount_inc(&p->tcfa_refcnt); *a = p; return true; } @@ -324,9 +336,9 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est, if (unlikely(!p)) return -ENOMEM; - p->tcfa_refcnt = 1; + refcount_set(&p->tcfa_refcnt, 1); if (bind) - p->tcfa_bindcnt = 1; + atomic_set(&p->tcfa_bindcnt, 1); if (cpustats) { p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu); @@ -782,7 +794,7 @@ static void cleanup_a(struct list_head *actions, int ovr) return; list_for_each_entry(a, actions, list) - a->tcfa_refcnt--; + refcount_dec(&a->tcfa_refcnt); } int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla, @@ -810,7 +822,7 @@ int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla, act->order = i; sz += tcf_action_fill_size(act); if (ovr) - act->tcfa_refcnt++; + refcount_inc(&act->tcfa_refcnt); list_add_tail(&act->list, actions); } |