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authorVlad Buslov <vladbu@mellanox.com>2018-08-10 20:51:51 +0300
committerDavid S. Miller <davem@davemloft.net>2018-08-11 22:37:10 +0300
commit764e9a24480f6ffba5493fb21e6a7b030d6b8b67 (patch)
treefc393dce078fb6d5ac6014f0e72eca289ef6b33e /net
parent729e01260989cc06c8a78491b46545793aef323a (diff)
downloadlinux-764e9a24480f6ffba5493fb21e6a7b030d6b8b67.tar.xz
net: sched: act_vlan: remove dependency on rtnl lock
Use tcf spinlock to protect vlan action private data from concurrent modification during dump and init. Use rcu swap operation to reassign params pointer under protection of tcf lock. (old params value is not used by init, so there is no need of standalone rcu dereference step) Remove rtnl assertion that is no longer necessary. Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/sched/act_vlan.c27
1 files changed, 15 insertions, 12 deletions
diff --git a/net/sched/act_vlan.c b/net/sched/act_vlan.c
index 15a0ee214c9c..5bde17fe3608 100644
--- a/net/sched/act_vlan.c
+++ b/net/sched/act_vlan.c
@@ -109,7 +109,7 @@ static int tcf_vlan_init(struct net *net, struct nlattr *nla,
{
struct tc_action_net *tn = net_generic(net, vlan_net_id);
struct nlattr *tb[TCA_VLAN_MAX + 1];
- struct tcf_vlan_params *p, *p_old;
+ struct tcf_vlan_params *p;
struct tc_vlan *parm;
struct tcf_vlan *v;
int action;
@@ -202,26 +202,24 @@ static int tcf_vlan_init(struct net *net, struct nlattr *nla,
v = to_vlan(*a);
- ASSERT_RTNL();
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p) {
tcf_idr_release(*a, bind);
return -ENOMEM;
}
- v->tcf_action = parm->action;
-
- p_old = rtnl_dereference(v->vlan_p);
-
p->tcfv_action = action;
p->tcfv_push_vid = push_vid;
p->tcfv_push_prio = push_prio;
p->tcfv_push_proto = push_proto;
- rcu_assign_pointer(v->vlan_p, p);
+ spin_lock(&v->tcf_lock);
+ v->tcf_action = parm->action;
+ rcu_swap_protected(v->vlan_p, p, lockdep_is_held(&v->tcf_lock));
+ spin_unlock(&v->tcf_lock);
- if (p_old)
- kfree_rcu(p_old, rcu);
+ if (p)
+ kfree_rcu(p, rcu);
if (ret == ACT_P_CREATED)
tcf_idr_insert(tn, *a);
@@ -243,16 +241,18 @@ static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_vlan *v = to_vlan(a);
- struct tcf_vlan_params *p = rtnl_dereference(v->vlan_p);
+ struct tcf_vlan_params *p;
struct tc_vlan opt = {
.index = v->tcf_index,
.refcnt = refcount_read(&v->tcf_refcnt) - ref,
.bindcnt = atomic_read(&v->tcf_bindcnt) - bind,
- .action = v->tcf_action,
- .v_action = p->tcfv_action,
};
struct tcf_t t;
+ spin_lock(&v->tcf_lock);
+ opt.action = v->tcf_action;
+ p = rcu_dereference_protected(v->vlan_p, lockdep_is_held(&v->tcf_lock));
+ opt.v_action = p->tcfv_action;
if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
@@ -268,9 +268,12 @@ static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
tcf_tm_dump(&t, &v->tcf_tm);
if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
goto nla_put_failure;
+ spin_unlock(&v->tcf_lock);
+
return skb->len;
nla_put_failure:
+ spin_unlock(&v->tcf_lock);
nlmsg_trim(skb, b);
return -1;
}