Merge branch 'net_sched-act-extend-rcu-use-in-dump-methods'

Eric Dumazet says:

====================
net_sched: act: extend RCU use in dump() methods

We are trying to get away from central RTNL in favor of fine-grained
mutexes. While looking at net/sched, I found that act already uses
RCU in the fast path for the most cases, and could also be used
in dump() methods.

This series is not complete and will be followed by a second one.

v1: https://lore.kernel.org/20250707130110.619822-1-edumazet@google.com
====================

Link: https://patch.msgid.link/20250709090204.797558-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

10 files changed, 27 insertions, 14 deletions

diff --git a/include/net/act_api.h b/include/net/act_api.h
index 04781c92b43d..2894cfff2da3 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -76,19 +76,24 @@ static inline void tcf_lastuse_update(struct tcf_t *tm)
 {
 	unsigned long now = jiffies;
 
-	if (tm->lastuse != now)
-		tm->lastuse = now;
-	if (unlikely(!tm->firstuse))
-		tm->firstuse = now;
+	if (READ_ONCE(tm->lastuse) != now)
+		WRITE_ONCE(tm->lastuse, now);
+	if (unlikely(!READ_ONCE(tm->firstuse)))
+		WRITE_ONCE(tm->firstuse, now);
 }
 
 static inline void tcf_tm_dump(struct tcf_t *dtm, const struct tcf_t *stm)
 {
-	dtm->install = jiffies_to_clock_t(jiffies - stm->install);
-	dtm->lastuse = jiffies_to_clock_t(jiffies - stm->lastuse);
-	dtm->firstuse = stm->firstuse ?
-		jiffies_to_clock_t(jiffies - stm->firstuse) : 0;
-	dtm->expires = jiffies_to_clock_t(stm->expires);
+	unsigned long firstuse, now = jiffies;
+
+	dtm->install = jiffies_to_clock_t(now - READ_ONCE(stm->install));
+	dtm->lastuse = jiffies_to_clock_t(now - READ_ONCE(stm->lastuse));
+
+	firstuse = READ_ONCE(stm->firstuse);
+	dtm->firstuse = firstuse ?
+		jiffies_to_clock_t(now - firstuse) : 0;
+
+	dtm->expires = jiffies_to_clock_t(READ_ONCE(stm->expires));
 }
 
 static inline enum flow_action_hw_stats tc_act_hw_stats(u8 hw_stats)
diff --git a/include/net/tc_act/tc_connmark.h b/include/net/tc_act/tc_connmark.h
index e8dd77a96748..a5ce83f3eea4 100644
--- a/include/net/tc_act/tc_connmark.h
+++ b/include/net/tc_act/tc_connmark.h
@@ -7,6 +7,7 @@
 struct tcf_connmark_parms {
 	struct net *net;
 	u16 zone;
+	int action;
 	struct rcu_head rcu;
 };
 
diff --git a/include/net/tc_act/tc_csum.h b/include/net/tc_act/tc_csum.h
index 2515da0142a6..8d0c7a9f9345 100644
--- a/include/net/tc_act/tc_csum.h
+++ b/include/net/tc_act/tc_csum.h
@@ -8,6 +8,7 @@
 
 struct tcf_csum_params {
 	u32 update_flags;
+	int action;
 	struct rcu_head rcu;
 };
 
diff --git a/include/net/tc_act/tc_ct.h b/include/net/tc_act/tc_ct.h
index e6b45cb27ebf..8b90c86c0b0d 100644
--- a/include/net/tc_act/tc_ct.h
+++ b/include/net/tc_act/tc_ct.h
@@ -13,7 +13,7 @@ struct tcf_ct_params {
 	struct nf_conntrack_helper *helper;
 	struct nf_conn *tmpl;
 	u16 zone;
-
+	int action;
 	u32 mark;
 	u32 mark_mask;
 
diff --git a/include/net/tc_act/tc_ctinfo.h b/include/net/tc_act/tc_ctinfo.h
index f071c1d70a25..7fe01ab236da 100644
--- a/include/net/tc_act/tc_ctinfo.h
+++ b/include/net/tc_act/tc_ctinfo.h
@@ -7,6 +7,7 @@
 struct tcf_ctinfo_params {
 	struct rcu_head rcu;
 	struct net *net;
+	int action;
 	u32 dscpmask;
 	u32 dscpstatemask;
 	u32 cpmarkmask;
@@ -18,9 +19,9 @@ struct tcf_ctinfo_params {
 struct tcf_ctinfo {
 	struct tc_action common;
 	struct tcf_ctinfo_params __rcu *params;
-	u64 stats_dscp_set;
-	u64 stats_dscp_error;
-	u64 stats_cpmark_set;
+	atomic64_t stats_dscp_set;
+	atomic64_t stats_dscp_error;
+	atomic64_t stats_cpmark_set;
 };
 
 enum {
diff --git a/include/net/tc_act/tc_mpls.h b/include/net/tc_act/tc_mpls.h
index d452e5e94fd0..dd067bd4018d 100644
--- a/include/net/tc_act/tc_mpls.h
+++ b/include/net/tc_act/tc_mpls.h
@@ -10,6 +10,7 @@
 struct tcf_mpls_params {
 	int tcfm_action;
 	u32 tcfm_label;
+	int action; /* tcf_action */
 	u8 tcfm_tc;
 	u8 tcfm_ttl;
 	u8 tcfm_bos;
diff --git a/include/net/tc_act/tc_nat.h b/include/net/tc_act/tc_nat.h
index c869274ac529..ae35f4009445 100644
--- a/include/net/tc_act/tc_nat.h
+++ b/include/net/tc_act/tc_nat.h
@@ -6,6 +6,7 @@
 #include <net/act_api.h>
 
 struct tcf_nat_parms {
+	int action;
 	__be32 old_addr;
 	__be32 new_addr;
 	__be32 mask;
diff --git a/include/net/tc_act/tc_pedit.h b/include/net/tc_act/tc_pedit.h
index 83fe39931781..f58ee15cd858 100644
--- a/include/net/tc_act/tc_pedit.h
+++ b/include/net/tc_act/tc_pedit.h
@@ -14,6 +14,7 @@ struct tcf_pedit_key_ex {
 struct tcf_pedit_parms {
 	struct tc_pedit_key	*tcfp_keys;
 	struct tcf_pedit_key_ex	*tcfp_keys_ex;
+	int action;
 	u32 tcfp_off_max_hint;
 	unsigned char tcfp_nkeys;
 	unsigned char tcfp_flags;
diff --git a/include/net/tc_act/tc_police.h b/include/net/tc_act/tc_police.h
index 490d88cb5233..a89fc8e68b1e 100644
--- a/include/net/tc_act/tc_police.h
+++ b/include/net/tc_act/tc_police.h
@@ -5,10 +5,11 @@
 #include <net/act_api.h>
 
 struct tcf_police_params {
+	int			action;
 	int			tcfp_result;
 	u32			tcfp_ewma_rate;
-	s64			tcfp_burst;
 	u32			tcfp_mtu;
+	s64			tcfp_burst;
 	s64			tcfp_mtu_ptoks;
 	s64			tcfp_pkt_burst;
 	struct psched_ratecfg	rate;
diff --git a/include/net/tc_act/tc_skbedit.h b/include/net/tc_act/tc_skbedit.h
index 9649600fb3dc..31b2cd0bebb5 100644
--- a/include/net/tc_act/tc_skbedit.h
+++ b/include/net/tc_act/tc_skbedit.h
@@ -12,6 +12,7 @@
 #include <linux/tc_act/tc_skbedit.h>
 
 struct tcf_skbedit_params {
+	int action;
 	u32 flags;
 	u32 priority;
 	u32 mark;