[PATCH 02/14] net: sched: change type of reference and bind counters

Vlad Buslov
2018-05-14T14:32:19Z

Change type of action reference counter to refcount_t.

Change type of action bind counter to atomic_t.
This type is used to allow decrementing bind counter without testing
for 0 result.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
---
include/net/act_api.h | 5 +++--
net/sched/act_api.c | 32 ++++++++++++++++++++++----------
net/sched/act_bpf.c | 4 ++--
net/sched/act_connmark.c | 4 ++--
net/sched/act_csum.c | 4 ++--
net/sched/act_gact.c | 4 ++--
net/sched/act_ife.c | 4 ++--
net/sched/act_ipt.c | 4 ++--
net/sched/act_mirred.c | 4 ++--
net/sched/act_nat.c | 4 ++--
net/sched/act_pedit.c | 4 ++--
net/sched/act_police.c | 4 ++--
net/sched/act_sample.c | 4 ++--
net/sched/act_simple.c | 4 ++--
net/sched/act_skbedit.c | 4 ++--
net/sched/act_skbmod.c | 4 ++--
net/sched/act_tunnel_key.c | 4 ++--
net/sched/act_vlan.c | 4 ++--
18 files changed, 57 insertions(+), 44 deletions(-)

diff --git a/include/net/act_api.h b/include/net/act_api.h
index f7b59ef..e634014 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -6,6 +6,7 @@
* Public action API for classifiers/qdiscs
*/

+#include <linux/refcount.h>
#include <net/sch_generic.h>
#include <net/pkt_sched.h>
#include <net/net_namespace.h>
@@ -26,8 +27,8 @@ struct tc_action {
struct tcf_idrinfo *idrinfo;

u32 tcfa_index;
- int tcfa_refcnt;
- int tcfa_bindcnt;
+ refcount_t tcfa_refcnt;
+ atomic_t tcfa_bindcnt;
u32 tcfa_capab;
int tcfa_action;
struct tcf_t tcfa_tm;
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index ce829a3..96b0878 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -105,14 +105,26 @@ int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)

ASSERT_RTNL();

+ /* Release with strict==1 and bind==0 is only called through act API
+ * interface (classifiers always bind). Only case when action with
+ * positive reference count and zero bind count can exist is when it was
+ * also created with act API (unbinding last classifier will destroy the
+ * action if it was created by classifier). So only case when bind count
+ * can be changed after initial check is when unbound action is
+ * destroyed by act API while classifier binds to action with same id
+ * concurrently. This result either creation of new action(same behavior
+ * as before), or reusing existing action if concurrent process
+ * increments reference count before action is deleted. Both scenarios
+ * are acceptable.
+ */
if (p) {
if (bind)
- p->tcfa_bindcnt--;
- else if (strict && p->tcfa_bindcnt > 0)
+ atomic_dec(&p->tcfa_bindcnt);
+ else if (strict && atomic_read(&p->tcfa_bindcnt) > 0)
return -EPERM;

- p->tcfa_refcnt--;
- if (p->tcfa_bindcnt <= 0 && p->tcfa_refcnt <= 0) {
+ if (atomic_read(&p->tcfa_bindcnt) <= 0 &&
+ refcount_dec_and_test(&p->tcfa_refcnt)) {
if (p->ops->cleanup)
p->ops->cleanup(p);
tcf_idr_remove(p->idrinfo, p);
@@ -304,8 +316,8 @@ bool tcf_idr_check(struct tc_action_net *tn, u32 index, struct tc_action **a,

if (index && p) {
if (bind)
- p->tcfa_bindcnt++;
- p->tcfa_refcnt++;
+ atomic_inc(&p->tcfa_bindcnt);
+ refcount_inc(&p->tcfa_refcnt);
*a = p;
return true;
}
@@ -324,9 +336,9 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,

if (unlikely(!p))
return -ENOMEM;
- p->tcfa_refcnt = 1;
+ refcount_set(&p->tcfa_refcnt, 1);
if (bind)
- p->tcfa_bindcnt = 1;
+ atomic_set(&p->tcfa_bindcnt, 1);

if (cpustats) {
p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
@@ -782,7 +794,7 @@ static void cleanup_a(struct list_head *actions, int ovr)
return;

list_for_each_entry(a, actions, list)
- a->tcfa_refcnt--;
+ refcount_dec(&a->tcfa_refcnt);
}

int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
@@ -810,7 +822,7 @@ int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
act->order = i;
sz += tcf_action_fill_size(act);
if (ovr)
- act->tcfa_refcnt++;
+ refcount_inc(&act->tcfa_refcnt);
list_add_tail(&act->list, actions);
}

diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c
index 18089c0..15a2a53 100644
--- a/net/sched/act_bpf.c
+++ b/net/sched/act_bpf.c
@@ -141,8 +141,8 @@ static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act,
struct tcf_bpf *prog = to_bpf(act);
struct tc_act_bpf opt = {
.index = prog->tcf_index,
- .refcnt = prog->tcf_refcnt - ref,
- .bindcnt = prog->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&prog->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&prog->tcf_bindcnt) - bind,
.action = prog->tcf_action,
};
struct tcf_t tm;
diff --git a/net/sched/act_connmark.c b/net/sched/act_connmark.c
index e4b880f..1888650 100644
--- a/net/sched/act_connmark.c
+++ b/net/sched/act_connmark.c
@@ -154,8 +154,8 @@ static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a,

struct tc_connmark opt = {
.index = ci->tcf_index,
- .refcnt = ci->tcf_refcnt - ref,
- .bindcnt = ci->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&ci->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind,
.action = ci->tcf_action,
.zone = ci->zone,
};
diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c
index 7e28b2c..0572682 100644
--- a/net/sched/act_csum.c
+++ b/net/sched/act_csum.c
@@ -597,8 +597,8 @@ static int tcf_csum_dump(struct sk_buff *skb, struct tc_action *a, int bind,
struct tcf_csum_params *params;
struct tc_csum opt = {
.index = p->tcf_index,
- .refcnt = p->tcf_refcnt - ref,
- .bindcnt = p->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&p->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&p->tcf_bindcnt) - bind,
};
struct tcf_t t;

diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c
index 4dc4f15..ca83deb 100644
--- a/net/sched/act_gact.c
+++ b/net/sched/act_gact.c
@@ -169,8 +169,8 @@ static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a,
struct tcf_gact *gact = to_gact(a);
struct tc_gact opt = {
.index = gact->tcf_index,
- .refcnt = gact->tcf_refcnt - ref,
- .bindcnt = gact->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&gact->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind,
.action = gact->tcf_action,
};
struct tcf_t t;
diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c
index a5994cf..689f63e 100644
--- a/net/sched/act_ife.c
+++ b/net/sched/act_ife.c
@@ -598,8 +598,8 @@ static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
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,
+ .refcnt = refcount_read(&ife->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&ife->tcf_bindcnt) - bind,
.action = ife->tcf_action,
.flags = p->flags,
};
diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c
index 14c312d..7bce88d 100644
--- a/net/sched/act_ipt.c
+++ b/net/sched/act_ipt.c
@@ -280,8 +280,8 @@ static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind,
if (unlikely(!t))
goto nla_put_failure;

- c.bindcnt = ipt->tcf_bindcnt - bind;
- c.refcnt = ipt->tcf_refcnt - ref;
+ c.bindcnt = atomic_read(&ipt->tcf_bindcnt) - bind;
+ c.refcnt = refcount_read(&ipt->tcf_refcnt) - ref;
strcpy(t->u.user.name, ipt->tcfi_t->u.kernel.target->name);

if (nla_put(skb, TCA_IPT_TARG, ipt->tcfi_t->u.user.target_size, t) ||
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
index fd34015..82a8bdd 100644
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -250,8 +250,8 @@ static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind,
struct tc_mirred opt = {
.index = m->tcf_index,
.action = m->tcf_action,
- .refcnt = m->tcf_refcnt - ref,
- .bindcnt = m->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&m->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
.eaction = m->tcfm_eaction,
.ifindex = dev ? dev->ifindex : 0,
};
diff --git a/net/sched/act_nat.c b/net/sched/act_nat.c
index 4b5848b..457c2ae 100644
--- a/net/sched/act_nat.c
+++ b/net/sched/act_nat.c
@@ -257,8 +257,8 @@ static int tcf_nat_dump(struct sk_buff *skb, struct tc_action *a,

.index = p->tcf_index,
.action = p->tcf_action,
- .refcnt = p->tcf_refcnt - ref,
- .bindcnt = p->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&p->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&p->tcf_bindcnt) - bind,
};
struct tcf_t t;

diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c
index 8a925c7..0102b29 100644
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -391,8 +391,8 @@ static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
opt->nkeys = p->tcfp_nkeys;
opt->flags = p->tcfp_flags;
opt->action = p->tcf_action;
- opt->refcnt = p->tcf_refcnt - ref;
- opt->bindcnt = p->tcf_bindcnt - bind;
+ opt->refcnt = refcount_read(&p->tcf_refcnt) - ref;
+ opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind;

if (p->tcfp_keys_ex) {
tcf_pedit_key_ex_dump(skb, p->tcfp_keys_ex, p->tcfp_nkeys);
diff --git a/net/sched/act_police.c b/net/sched/act_police.c
index 4e72bc2..a789b80 100644
--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -274,8 +274,8 @@ static int tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a,
.action = police->tcf_action,
.mtu = police->tcfp_mtu,
.burst = PSCHED_NS2TICKS(police->tcfp_burst),
- .refcnt = police->tcf_refcnt - ref,
- .bindcnt = police->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&police->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&police->tcf_bindcnt) - bind,
};
struct tcf_t t;

diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c
index 5db3584..4a46978 100644
--- a/net/sched/act_sample.c
+++ b/net/sched/act_sample.c
@@ -173,8 +173,8 @@ static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a,
struct tc_sample opt = {
.index = s->tcf_index,
.action = s->tcf_action,
- .refcnt = s->tcf_refcnt - ref,
- .bindcnt = s->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&s->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&s->tcf_bindcnt) - bind,
};
struct tcf_t t;

diff --git a/net/sched/act_simple.c b/net/sched/act_simple.c
index 9618b4a8..95d5985 100644
--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c
@@ -148,8 +148,8 @@ static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
struct tcf_defact *d = to_defact(a);
struct tc_defact opt = {
.index = d->tcf_index,
- .refcnt = d->tcf_refcnt - ref,
- .bindcnt = d->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&d->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
.action = d->tcf_action,
};
struct tcf_t t;
diff --git a/net/sched/act_skbedit.c b/net/sched/act_skbedit.c
index ddf69fc..adf0a72 100644
--- a/net/sched/act_skbedit.c
+++ b/net/sched/act_skbedit.c
@@ -172,8 +172,8 @@ static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
struct tcf_skbedit *d = to_skbedit(a);
struct tc_skbedit opt = {
.index = d->tcf_index,
- .refcnt = d->tcf_refcnt - ref,
- .bindcnt = d->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&d->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
.action = d->tcf_action,
};
struct tcf_t t;
diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
index bbcbdce..a0d9abb 100644
--- a/net/sched/act_skbmod.c
+++ b/net/sched/act_skbmod.c
@@ -202,8 +202,8 @@ static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a,
struct tcf_skbmod_params *p = rtnl_dereference(d->skbmod_p);
struct tc_skbmod opt = {
.index = d->tcf_index,
- .refcnt = d->tcf_refcnt - ref,
- .bindcnt = d->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&d->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
.action = d->tcf_action,
};
struct tcf_t t;
diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c
index 626dac8..c6e5069 100644
--- a/net/sched/act_tunnel_key.c
+++ b/net/sched/act_tunnel_key.c
@@ -252,8 +252,8 @@ static int tunnel_key_dump(struct sk_buff *skb, struct tc_action *a,
struct tcf_tunnel_key_params *params;
struct tc_tunnel_key opt = {
.index = t->tcf_index,
- .refcnt = t->tcf_refcnt - ref,
- .bindcnt = t->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&t->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&t->tcf_bindcnt) - bind,
};
struct tcf_t tm;

diff --git a/net/sched/act_vlan.c b/net/sched/act_vlan.c
index 8536046..8dda784 100644
--- a/net/sched/act_vlan.c
+++ b/net/sched/act_vlan.c
@@ -237,8 +237,8 @@ static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
struct tcf_vlan_params *p = rtnl_dereference(v->vlan_p);
struct tc_vlan opt = {
.index = v->tcf_index,
- .refcnt = v->tcf_refcnt - ref,
- .bindcnt = v->tcf_bindcnt - bind,
+ .refcnt = refcount_read(&v->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&v->tcf_bindcnt) - bind,
.action = v->tcf_action,
.v_action = p->tcfv_action,
};
--
2.7.5