From: Vlad Buslov <vladbu@mellanox.com>
Date: Thu, 5 Jul 2018 17:24:33 +0300
Subject: net: sched: change action API to use array of pointers to actions
Patch-mainline: v4.19-rc1
Git-commit: 90b73b77d08ec395311411b545c756ca710aae59
References: bsc#1109837
Act API used linked list to pass set of actions to functions. It is
intrusive data structure that stores list nodes inside action structure
itself, which means it is not safe to modify such list concurrently.
However, action API doesn't use any linked list specific operations on this
set of actions, so it can be safely refactored into plain pointer array.
Refactor action API to use array of pointers to tc_actions instead of
linked list. Change argument 'actions' type of exported action init,
destroy and dump functions.
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
include/net/act_api.h | 7 ++-
net/sched/act_api.c | 89 ++++++++++++++++++++++++++++----------------------
net/sched/cls_api.c | 21 +++--------
3 files changed, 60 insertions(+), 57 deletions(-)
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -169,19 +169,20 @@ static inline int tcf_idr_release(struct
int tcf_register_action(struct tc_action_ops *a, struct pernet_operations *ops);
int tcf_unregister_action(struct tc_action_ops *a,
struct pernet_operations *ops);
-int tcf_action_destroy(struct list_head *actions, int bind);
+int tcf_action_destroy(struct tc_action *actions[], int bind);
int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
int nr_actions, struct tcf_result *res);
int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
struct nlattr *est, char *name, int ovr, int bind,
- struct list_head *actions, size_t *attr_size,
+ struct tc_action *actions[], size_t *attr_size,
bool rtnl_held, struct netlink_ext_ack *extack);
struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
struct nlattr *nla, struct nlattr *est,
char *name, int ovr, int bind,
bool rtnl_held,
struct netlink_ext_ack *extack);
-int tcf_action_dump(struct sk_buff *skb, struct list_head *, int, int);
+int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[], int bind,
+ int ref);
int tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int, int);
int tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int, int);
int tcf_action_copy_stats(struct sk_buff *, struct tc_action *, int);
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -658,13 +658,15 @@ repeat:
}
EXPORT_SYMBOL(tcf_action_exec);
-int tcf_action_destroy(struct list_head *actions, int bind)
+int tcf_action_destroy(struct tc_action *actions[], int bind)
{
const struct tc_action_ops *ops;
- struct tc_action *a, *tmp;
- int ret = 0;
+ struct tc_action *a;
+ int ret = 0, i;
- list_for_each_entry_safe(a, tmp, actions, list) {
+ for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
+ a = actions[i];
+ actions[i] = NULL;
ops = a->ops;
ret = __tcf_idr_release(a, bind, true);
if (ret == ACT_P_DELETED)
@@ -680,11 +682,12 @@ static int tcf_action_put(struct tc_acti
return __tcf_action_put(p, false);
}
-static void tcf_action_put_lst(struct list_head *actions)
+static void tcf_action_put_many(struct tc_action *actions[])
{
- struct tc_action *a, *tmp;
+ int i;
- list_for_each_entry_safe(a, tmp, actions, list) {
+ for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
+ struct tc_action *a = actions[i];
const struct tc_action_ops *ops = a->ops;
if (tcf_action_put(a))
@@ -736,14 +739,15 @@ nla_put_failure:
}
EXPORT_SYMBOL(tcf_action_dump_1);
-int tcf_action_dump(struct sk_buff *skb, struct list_head *actions,
+int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
int bind, int ref)
{
struct tc_action *a;
- int err = -EINVAL;
+ int err = -EINVAL, i;
struct nlattr *nest;
- list_for_each_entry(a, actions, list) {
+ for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
+ a = actions[i];
nest = nla_nest_start(skb, a->order);
if (nest == NULL)
goto nla_put_failure;
@@ -879,10 +883,9 @@ struct tc_action *tcf_action_init_1(stru
if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN)) {
err = tcf_action_goto_chain_init(a, tp);
if (err) {
- LIST_HEAD(actions);
+ struct tc_action *actions[] = { a, NULL };
- list_add_tail(&a->list, &actions);
- tcf_action_destroy(&actions, bind);
+ tcf_action_destroy(actions, bind);
NL_SET_ERR_MSG(extack, "Failed to init TC action chain");
return ERR_PTR(err);
}
@@ -900,9 +903,11 @@ err_out:
return ERR_PTR(err);
}
+/* Returns numbers of initialized actions or negative error. */
+
int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
struct nlattr *est, char *name, int ovr, int bind,
- struct list_head *actions, size_t *attr_size,
+ struct tc_action *actions[], size_t *attr_size,
bool rtnl_held, struct netlink_ext_ack *extack)
{
struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
@@ -924,11 +929,12 @@ int tcf_action_init(struct net *net, str
}
act->order = i;
sz += tcf_action_fill_size(act);
- list_add_tail(&act->list, actions);
+ /* Start from index 0 */
+ actions[i - 1] = act;
}
*attr_size = tcf_action_full_attrs_size(sz);
- return 0;
+ return i - 1;
err:
tcf_action_destroy(actions, bind);
@@ -979,7 +985,7 @@ errout:
return -1;
}
-static int tca_get_fill(struct sk_buff *skb, struct list_head *actions,
+static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
u32 portid, u32 seq, u16 flags, int event, int bind,
int ref)
{
@@ -1015,7 +1021,7 @@ out_nlmsg_trim:
static int
tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
- struct list_head *actions, int event,
+ struct tc_action *actions[], int event,
struct netlink_ext_ack *extack)
{
struct sk_buff *skb;
@@ -1151,14 +1157,14 @@ err_out:
return err;
}
-static int tcf_action_delete(struct net *net, struct list_head *actions,
- struct netlink_ext_ack *extack)
+static int tcf_action_delete(struct net *net, struct tc_action *actions[],
+ int *acts_deleted, struct netlink_ext_ack *extack)
{
- struct tc_action *a, *tmp;
u32 act_index;
- int ret;
+ int ret, i;
- list_for_each_entry_safe(a, tmp, actions, list) {
+ for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
+ struct tc_action *a = actions[i];
const struct tc_action_ops *ops = a->ops;
/* Actions can be deleted concurrently so we must save their
@@ -1166,23 +1172,26 @@ static int tcf_action_delete(struct net
*/
act_index = a->tcfa_index;
- list_del(&a->list);
if (tcf_action_put(a)) {
/* last reference, action was deleted concurrently */
module_put(ops->owner);
} else {
/* now do the delete */
ret = ops->delete(net, act_index);
- if (ret < 0)
+ if (ret < 0) {
+ *acts_deleted = i + 1;
return ret;
+ }
}
}
+ *acts_deleted = i;
return 0;
}
static int
-tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
- u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
+tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
+ int *acts_deleted, u32 portid, size_t attr_size,
+ struct netlink_ext_ack *extack)
{
int ret;
struct sk_buff *skb;
@@ -1200,7 +1209,7 @@ tcf_del_notify(struct net *net, struct n
}
/* now do the delete */
- ret = tcf_action_delete(net, actions, extack);
+ ret = tcf_action_delete(net, actions, acts_deleted, extack);
if (ret < 0) {
NL_SET_ERR_MSG(extack, "Failed to delete TC action");
kfree_skb(skb);
@@ -1222,7 +1231,8 @@ tca_action_gd(struct net *net, struct nl
struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
struct tc_action *act;
size_t attr_size = 0;
- LIST_HEAD(actions);
+ struct tc_action *actions[TCA_ACT_MAX_PRIO + 1] = {};
+ int acts_deleted = 0;
ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
if (ret < 0)
@@ -1244,26 +1254,27 @@ tca_action_gd(struct net *net, struct nl
}
act->order = i;
attr_size += tcf_action_fill_size(act);
- list_add_tail(&act->list, &actions);
+ actions[i - 1] = act;
}
attr_size = tcf_action_full_attrs_size(attr_size);
if (event == RTM_GETACTION)
- ret = tcf_get_notify(net, portid, n, &actions, event, extack);
+ ret = tcf_get_notify(net, portid, n, actions, event, extack);
else { /* delete */
- ret = tcf_del_notify(net, n, &actions, portid, attr_size, extack);
+ ret = tcf_del_notify(net, n, actions, &acts_deleted, portid,
+ attr_size, extack);
if (ret)
goto err;
return ret;
}
err:
- tcf_action_put_lst(&actions);
+ tcf_action_put_many(&actions[acts_deleted]);
return ret;
}
static int
-tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
+tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
{
struct sk_buff *skb;
@@ -1294,15 +1305,15 @@ static int tcf_action_add(struct net *ne
{
size_t attr_size = 0;
int ret = 0;
- LIST_HEAD(actions);
+ struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
- ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0, &actions,
+ ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0, actions,
&attr_size, true, extack);
- if (ret)
+ if (ret < 0)
return ret;
- ret = tcf_add_notify(net, n, &actions, portid, attr_size, extack);
+ ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
if (ovr)
- tcf_action_put_lst(&actions);
+ tcf_action_put_many(actions);
return ret;
}
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1609,10 +1609,7 @@ out:
void tcf_exts_destroy(struct tcf_exts *exts)
{
#ifdef CONFIG_NET_CLS_ACT
- LIST_HEAD(actions);
-
- tcf_exts_to_list(exts, &actions);
- tcf_action_destroy(&actions, TCA_ACT_UNBIND);
+ tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
kfree(exts->actions);
exts->nr_actions = 0;
#endif
@@ -1639,18 +1636,15 @@ int tcf_exts_validate(struct net *net, s
exts->actions[0] = act;
exts->nr_actions = 1;
} else if (exts->action && tb[exts->action]) {
- LIST_HEAD(actions);
- int err, i = 0;
+ int err;
err = tcf_action_init(net, tp, tb[exts->action],
rate_tlv, NULL, ovr, TCA_ACT_BIND,
- &actions, &attr_size, true,
+ exts->actions, &attr_size, true,
extack);
- if (err)
+ if (err < 0)
return err;
- list_for_each_entry(act, &actions, list)
- exts->actions[i++] = act;
- exts->nr_actions = i;
+ exts->nr_actions = err;
}
exts->net = net;
}
@@ -1699,14 +1693,11 @@ int tcf_exts_dump(struct sk_buff *skb, s
* tc data even if iproute2 was newer - jhs
*/
if (exts->type != TCA_OLD_COMPAT) {
- LIST_HEAD(actions);
-
nest = nla_nest_start(skb, exts->action);
if (nest == NULL)
goto nla_put_failure;
- tcf_exts_to_list(exts, &actions);
- if (tcf_action_dump(skb, &actions, 0, 0) < 0)
+ if (tcf_action_dump(skb, exts->actions, 0, 0) < 0)
goto nla_put_failure;
nla_nest_end(skb, nest);
} else if (exts->police) {