[PATCH v2 05/11] net: sched: implement action API that deletes action by index

Vlad Buslov
2018-05-27T16:42:05Z

Implement new action API function that atomically finds and deletes action
from idr by index. Intended to be used by lockless actions that do not rely
on rtnl lock.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
---
include/net/act_api.h | 1 +
net/sched/act_api.c | 39 +++++++++++++++++++++++++++++++++++++++
2 files changed, 40 insertions(+)

diff --git a/include/net/act_api.h b/include/net/act_api.h
index 888ff471bbf6..d94ec6400673 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -153,6 +153,7 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
int bind, bool cpustats);
void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a);

+int tcf_idr_delete_index(struct tc_action_net *tn, u32 index);
int __tcf_idr_release(struct tc_action *a, bool bind, bool strict);

static inline int tcf_idr_release(struct tc_action *a, bool bind)
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index aa304d36fee0..0f31f09946ab 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -319,6 +319,45 @@ bool tcf_idr_check(struct tc_action_net *tn, u32 index, struct tc_action **a,
}
EXPORT_SYMBOL(tcf_idr_check);

+int tcf_idr_delete_index(struct tc_action_net *tn, u32 index)
+{
+ struct tcf_idrinfo *idrinfo = tn->idrinfo;
+ struct tc_action *p;
+ int ret = 0;
+
+ spin_lock(&idrinfo->lock);
+ p = idr_find(&idrinfo->action_idr, index);
+ if (!p) {
+ spin_unlock(&idrinfo->lock);
+ return -ENOENT;
+ }
+
+ if (!atomic_read(&p->tcfa_bindcnt)) {
+ if (refcount_dec_and_test(&p->tcfa_refcnt)) {
+ struct module *owner = p->ops->owner;
+
+ WARN_ON(p != idr_remove(&idrinfo->action_idr,
+ p->tcfa_index));
+ spin_unlock(&idrinfo->lock);
+
+ if (p->ops->cleanup)
+ p->ops->cleanup(p);
+
+ gen_kill_estimator(&p->tcfa_rate_est);
+ free_tcf(p);
+ module_put(owner);
+ return 0;
+ }
+ ret = 0;
+ } else {
+ ret = -EPERM;
+ }
+
+ spin_unlock(&idrinfo->lock);
+ return ret;
+}
+EXPORT_SYMBOL(tcf_idr_delete_index);
+
int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
struct tc_action **a, const struct tc_action_ops *ops,
int bind, bool cpustats)
--
2.7.5