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Date: Wed, 11 Oct 2017 17:16:08 -0400
From: Alexander Aring <aring@...atatu.com>
To: jhs@...atatu.com
Cc: xiyou.wangcong@...il.com, jiri@...nulli.us, netdev@...r.kernel.org,
eric.dumazet@...il.com, bjb@...atatu.com,
Alexander Aring <aring@...atatu.com>
Subject: [PATCH net-next 3/3] sched: act: ife: update parameters via rcu handling
This patch changes the parameter updating via RCU and not protected by a
spinlock anymore. This reduce the time that the spinlock is being held.
Signed-off-by: Alexander Aring <aring@...atatu.com>
---
include/net/tc_act/tc_ife.h | 10 ++++--
net/sched/act_ife.c | 87 ++++++++++++++++++++++++++++++---------------
2 files changed, 67 insertions(+), 30 deletions(-)
diff --git a/include/net/tc_act/tc_ife.h b/include/net/tc_act/tc_ife.h
index 30ba459ddd34..16a84f6d43e2 100644
--- a/include/net/tc_act/tc_ife.h
+++ b/include/net/tc_act/tc_ife.h
@@ -6,12 +6,18 @@
#include <linux/rtnetlink.h>
#include <linux/module.h>
-struct tcf_ife_info {
- struct tc_action common;
+struct tcf_ife_params {
u8 eth_dst[ETH_ALEN];
u8 eth_src[ETH_ALEN];
u16 eth_type;
u16 flags;
+
+ struct rcu_head rcu;
+};
+
+struct tcf_ife_info {
+ struct tc_action common;
+ struct tcf_ife_params __rcu *params;
/* list of metaids allowed */
struct list_head metalist;
};
diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c
index f0d86b182387..2ef25c5582bb 100644
--- a/net/sched/act_ife.c
+++ b/net/sched/act_ife.c
@@ -392,10 +392,14 @@ static void _tcf_ife_cleanup(struct tc_action *a, int bind)
static void tcf_ife_cleanup(struct tc_action *a, int bind)
{
struct tcf_ife_info *ife = to_ife(a);
+ struct tcf_ife_params *p;
spin_lock_bh(&ife->tcf_lock);
_tcf_ife_cleanup(a, bind);
spin_unlock_bh(&ife->tcf_lock);
+
+ p = rcu_dereference_protected(ife->params, 1);
+ kfree_rcu(p, rcu);
}
/* under ife->tcf_lock for existing action */
@@ -432,6 +436,7 @@ static int tcf_ife_init(struct net *net, struct nlattr *nla,
struct tc_action_net *tn = net_generic(net, ife_net_id);
struct nlattr *tb[TCA_IFE_MAX + 1];
struct nlattr *tb2[IFE_META_MAX + 1];
+ struct tcf_ife_params *p, *p_old;
struct tcf_ife_info *ife;
u16 ife_type = ETH_P_IFE;
struct tc_ife *parm;
@@ -457,24 +462,34 @@ static int tcf_ife_init(struct net *net, struct nlattr *nla,
if (parm->flags & ~IFE_ENCODE)
return -EINVAL;
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+
exists = tcf_idr_check(tn, parm->index, a, bind);
- if (exists && bind)
+ if (exists && bind) {
+ kfree(p);
return 0;
+ }
if (!exists) {
ret = tcf_idr_create(tn, parm->index, est, a, &act_ife_ops,
bind, true);
- if (ret)
+ if (ret) {
+ kfree(p);
return ret;
+ }
ret = ACT_P_CREATED;
} else {
tcf_idr_release(*a, bind);
- if (!ovr)
+ if (!ovr) {
+ kfree(p);
return -EEXIST;
+ }
}
ife = to_ife(*a);
- ife->flags = parm->flags;
+ p->flags = parm->flags;
if (parm->flags & IFE_ENCODE) {
if (tb[TCA_IFE_TYPE])
@@ -485,24 +500,25 @@ static int tcf_ife_init(struct net *net, struct nlattr *nla,
saddr = nla_data(tb[TCA_IFE_SMAC]);
}
- if (exists)
- spin_lock_bh(&ife->tcf_lock);
ife->tcf_action = parm->action;
if (parm->flags & IFE_ENCODE) {
if (daddr)
- ether_addr_copy(ife->eth_dst, daddr);
+ ether_addr_copy(p->eth_dst, daddr);
else
- eth_zero_addr(ife->eth_dst);
+ eth_zero_addr(p->eth_dst);
if (saddr)
- ether_addr_copy(ife->eth_src, saddr);
+ ether_addr_copy(p->eth_src, saddr);
else
- eth_zero_addr(ife->eth_src);
+ eth_zero_addr(p->eth_src);
- ife->eth_type = ife_type;
+ p->eth_type = ife_type;
}
+ if (exists)
+ spin_lock_bh(&ife->tcf_lock);
+
if (ret == ACT_P_CREATED)
INIT_LIST_HEAD(&ife->metalist);
@@ -518,6 +534,7 @@ static int tcf_ife_init(struct net *net, struct nlattr *nla,
if (exists)
spin_unlock_bh(&ife->tcf_lock);
+ kfree(p);
return err;
}
@@ -538,6 +555,7 @@ static int tcf_ife_init(struct net *net, struct nlattr *nla,
if (exists)
spin_unlock_bh(&ife->tcf_lock);
+ kfree(p);
return err;
}
}
@@ -545,6 +563,11 @@ static int tcf_ife_init(struct net *net, struct nlattr *nla,
if (exists)
spin_unlock_bh(&ife->tcf_lock);
+ p_old = rtnl_dereference(ife->params);
+ rcu_assign_pointer(ife->params, p);
+ if (p_old)
+ kfree_rcu(p_old, rcu);
+
if (ret == ACT_P_CREATED)
tcf_idr_insert(tn, *a);
@@ -556,12 +579,13 @@ static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_ife_info *ife = to_ife(a);
+ struct tcf_ife_params *p = rtnl_dereference(ife->params);
struct tc_ife opt = {
.index = ife->tcf_index,
.refcnt = ife->tcf_refcnt - ref,
.bindcnt = ife->tcf_bindcnt - bind,
.action = ife->tcf_action,
- .flags = ife->flags,
+ .flags = p->flags,
};
struct tcf_t t;
@@ -572,17 +596,17 @@ static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
goto nla_put_failure;
- if (!is_zero_ether_addr(ife->eth_dst)) {
- if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, ife->eth_dst))
+ if (!is_zero_ether_addr(p->eth_dst)) {
+ if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, p->eth_dst))
goto nla_put_failure;
}
- if (!is_zero_ether_addr(ife->eth_src)) {
- if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, ife->eth_src))
+ if (!is_zero_ether_addr(p->eth_src)) {
+ if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, p->eth_src))
goto nla_put_failure;
}
- if (nla_put(skb, TCA_IFE_TYPE, 2, &ife->eth_type))
+ if (nla_put(skb, TCA_IFE_TYPE, 2, &p->eth_type))
goto nla_put_failure;
if (dump_metalist(skb, ife)) {
@@ -684,7 +708,7 @@ static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
}
static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
- struct tcf_result *res)
+ struct tcf_result *res, struct tcf_ife_params *p)
{
struct tcf_ife_info *ife = to_ife(a);
int action = ife->tcf_action;
@@ -748,19 +772,18 @@ static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
}
skboff += err;
}
+ spin_unlock(&ife->tcf_lock);
oethh = (struct ethhdr *)skb->data;
- if (!is_zero_ether_addr(ife->eth_src))
- ether_addr_copy(oethh->h_source, ife->eth_src);
- if (!is_zero_ether_addr(ife->eth_dst))
- ether_addr_copy(oethh->h_dest, ife->eth_dst);
- oethh->h_proto = htons(ife->eth_type);
+ if (!is_zero_ether_addr(p->eth_src))
+ ether_addr_copy(oethh->h_source, p->eth_src);
+ if (!is_zero_ether_addr(p->eth_dst))
+ ether_addr_copy(oethh->h_dest, p->eth_dst);
+ oethh->h_proto = htons(p->eth_type);
if (skb_at_tc_ingress(skb))
skb_pull(skb, skb->dev->hard_header_len);
- spin_unlock(&ife->tcf_lock);
-
return action;
}
@@ -768,9 +791,17 @@ static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_ife_info *ife = to_ife(a);
-
- if (ife->flags & IFE_ENCODE)
- return tcf_ife_encode(skb, a, res);
+ struct tcf_ife_params *p;
+ int ret;
+
+ rcu_read_lock();
+ p = rcu_dereference(ife->params);
+ if (p->flags & IFE_ENCODE) {
+ ret = tcf_ife_encode(skb, a, res, p);
+ rcu_read_unlock();
+ return ret;
+ }
+ rcu_read_unlock();
return tcf_ife_decode(skb, a, res);
}
--
2.11.0
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