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Diffstat (limited to 'net/sched/act_api.c')
-rw-r--r--net/sched/act_api.c92
1 files changed, 72 insertions, 20 deletions
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index eefe8c2fe667..9511502e1cbb 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -303,7 +303,9 @@ static bool __tcf_idr_check(struct tc_action_net *tn, u32 index,
spin_lock(&idrinfo->lock);
p = idr_find(&idrinfo->action_idr, index);
- if (p) {
+ if (IS_ERR(p)) {
+ p = NULL;
+ } else if (p) {
refcount_inc(&p->tcfa_refcnt);
if (bind)
atomic_inc(&p->tcfa_bindcnt);
@@ -371,7 +373,6 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
{
struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
struct tcf_idrinfo *idrinfo = tn->idrinfo;
- struct idr *idr = &idrinfo->action_idr;
int err = -ENOMEM;
if (unlikely(!p))
@@ -389,20 +390,6 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
goto err2;
}
spin_lock_init(&p->tcfa_lock);
- idr_preload(GFP_KERNEL);
- spin_lock(&idrinfo->lock);
- /* user doesn't specify an index */
- if (!index) {
- index = 1;
- err = idr_alloc_u32(idr, NULL, &index, UINT_MAX, GFP_ATOMIC);
- } else {
- err = idr_alloc_u32(idr, NULL, &index, index, GFP_ATOMIC);
- }
- spin_unlock(&idrinfo->lock);
- idr_preload_end();
- if (err)
- goto err3;
-
p->tcfa_index = index;
p->tcfa_tm.install = jiffies;
p->tcfa_tm.lastuse = jiffies;
@@ -412,7 +399,7 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
&p->tcfa_rate_est,
&p->tcfa_lock, NULL, est);
if (err)
- goto err4;
+ goto err3;
}
p->idrinfo = idrinfo;
@@ -420,8 +407,6 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
INIT_LIST_HEAD(&p->list);
*a = p;
return 0;
-err4:
- idr_remove(idr, index);
err3:
free_percpu(p->cpu_qstats);
err2:
@@ -437,11 +422,78 @@ void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
struct tcf_idrinfo *idrinfo = tn->idrinfo;
spin_lock(&idrinfo->lock);
- idr_replace(&idrinfo->action_idr, a, a->tcfa_index);
+ /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
+ WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
spin_unlock(&idrinfo->lock);
}
EXPORT_SYMBOL(tcf_idr_insert);
+/* Cleanup idr index that was allocated but not initialized. */
+
+void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
+{
+ struct tcf_idrinfo *idrinfo = tn->idrinfo;
+
+ spin_lock(&idrinfo->lock);
+ /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
+ WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
+ spin_unlock(&idrinfo->lock);
+}
+EXPORT_SYMBOL(tcf_idr_cleanup);
+
+/* Check if action with specified index exists. If actions is found, increments
+ * its reference and bind counters, and return 1. Otherwise insert temporary
+ * error pointer (to prevent concurrent users from inserting actions with same
+ * index) and return 0.
+ */
+
+int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
+ struct tc_action **a, int bind)
+{
+ struct tcf_idrinfo *idrinfo = tn->idrinfo;
+ struct tc_action *p;
+ int ret;
+
+again:
+ spin_lock(&idrinfo->lock);
+ if (*index) {
+ p = idr_find(&idrinfo->action_idr, *index);
+ if (IS_ERR(p)) {
+ /* This means that another process allocated
+ * index but did not assign the pointer yet.
+ */
+ spin_unlock(&idrinfo->lock);
+ goto again;
+ }
+
+ if (p) {
+ refcount_inc(&p->tcfa_refcnt);
+ if (bind)
+ atomic_inc(&p->tcfa_bindcnt);
+ *a = p;
+ ret = 1;
+ } else {
+ *a = NULL;
+ ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
+ *index, GFP_ATOMIC);
+ if (!ret)
+ idr_replace(&idrinfo->action_idr,
+ ERR_PTR(-EBUSY), *index);
+ }
+ } else {
+ *index = 1;
+ *a = NULL;
+ ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
+ UINT_MAX, GFP_ATOMIC);
+ if (!ret)
+ idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
+ *index);
+ }
+ spin_unlock(&idrinfo->lock);
+ return ret;
+}
+EXPORT_SYMBOL(tcf_idr_check_alloc);
+
void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
struct tcf_idrinfo *idrinfo)
{