[PATCH net-next 0/9] net: bridge: vlan: minor cleanups and annotations

[PATCH net-next 0/9] net: bridge: vlan: minor cleanups and annotations

[Nikolay Aleksandrov]

Hi,
In preparation for a complete vlan fast-path re-work, this set cleans up
a few minor things - removing legacy code barriers that don't help,
                     annotating lockless accesses and using proper helpers.
No functional changes are intended. Sashiko will find many pre-existing
problems, none of them are related to this set. I will try to fix
everything pre-existing separately in -net, there will probably be a few
critical items. So if there are missed places to annotate, or if there're
actual functional changes, these obviously should be addressed in this set.

Thanks,
 Nik

Nikolay Aleksandrov (9):
  net: bridge: vlan: drop legacy memory barriers
  net: bridge: vlan: annotate lockless pvid use
  net: bridge: mst: use br_get_pvid helper
  net: bridge: vlan: annotate lockless vlan flags use
  net: bridge: vlan: annotate lockless use of private flags
  net: bridge: vlan: annotate lockless use of num_vlans
  net: bridge: vlan: annotate lockless use of msti
  net: bridge: vlan: add missing tinfo.tunnel_id annotations
  net: bridge: vlan: use br_vlan_get_state to get vlan state

 net/bridge/br_arp_nd_proxy.c   |  6 ++++--
 net/bridge/br_mst.c            | 12 ++++++-----
 net/bridge/br_multicast.c      | 18 ++++++++++------
 net/bridge/br_netlink.c        | 10 ++++-----
 net/bridge/br_netlink_tunnel.c | 12 +++++------
 net/bridge/br_private.h        | 16 ++++++++------
 net/bridge/br_vlan.c           | 39 +++++++++++++++++-----------------
 net/bridge/br_vlan_options.c   |  6 ++++--
 net/bridge/br_vlan_tunnel.c    |  2 +-
 9 files changed, 67 insertions(+), 54 deletions(-)

-- 
2.47.3

[PATCH net-next 1/9] net: bridge: vlan: drop legacy memory barriers

[Nikolay Aleksandrov]

These memory barriers are legacy code from the old vlan implementation
that is not needed anymore. They're also affecting the fast-path.
The pvid is changed under lock and is read with rcu only in the fast-path
there is no need for a barrier, nothing to commit prior to changing it nor
invalidate prior to reading.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
 net/bridge/br_private.h | 1 -
 net/bridge/br_vlan.c    | 2 --
 2 files changed, 3 deletions(-)

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index d337b1cfb980..5b2c22ad669e 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1687,7 +1687,6 @@ static inline u16 br_get_pvid(const struct net_bridge_vlan_group *vg)
 	if (!vg)
 		return 0;
 
-	smp_rmb();
 	return vg->pvid;
 }
 
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 1e0e436629ec..2ae6ffb23399 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -40,7 +40,6 @@ static void __vlan_add_pvid(struct net_bridge_vlan_group *vg,
 	if (vg->pvid == v->vid)
 		return;
 
-	smp_wmb();
 	br_vlan_set_pvid_state(vg, v->state);
 	vg->pvid = v->vid;
 }
@@ -50,7 +49,6 @@ static void __vlan_delete_pvid(struct net_bridge_vlan_group *vg, u16 vid)
 	if (vg->pvid != vid)
 		return;
 
-	smp_wmb();
 	vg->pvid = 0;
 }
 
-- 
2.47.3

[PATCH net-next 2/9] net: bridge: vlan: annotate lockless pvid use

[Nikolay Aleksandrov]

Use READ/WRITE_ONCE to annotate lockless pvid use, br_get_pvid() is the
helper that should be used outside of the bridge vlan code. The rest of
the vlan places that access pvid directly all have rtnl.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
 net/bridge/br_private.h | 2 +-
 net/bridge/br_vlan.c    | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 5b2c22ad669e..0efd2e79e255 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1687,7 +1687,7 @@ static inline u16 br_get_pvid(const struct net_bridge_vlan_group *vg)
 	if (!vg)
 		return 0;
 
-	return vg->pvid;
+	return READ_ONCE(vg->pvid);
 }
 
 static inline u16 br_vlan_flags(const struct net_bridge_vlan *v, u16 pvid)
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 2ae6ffb23399..a53054fcc093 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -41,7 +41,7 @@ static void __vlan_add_pvid(struct net_bridge_vlan_group *vg,
 		return;
 
 	br_vlan_set_pvid_state(vg, v->state);
-	vg->pvid = v->vid;
+	WRITE_ONCE(vg->pvid, v->vid);
 }
 
 static void __vlan_delete_pvid(struct net_bridge_vlan_group *vg, u16 vid)
@@ -49,7 +49,7 @@ static void __vlan_delete_pvid(struct net_bridge_vlan_group *vg, u16 vid)
 	if (vg->pvid != vid)
 		return;
 
-	vg->pvid = 0;
+	WRITE_ONCE(vg->pvid, 0);
 }
 
 /* Update the BRIDGE_VLAN_INFO_PVID and BRIDGE_VLAN_INFO_UNTAGGED flags of @v.
-- 
2.47.3

[PATCH net-next 3/9] net: bridge: mst: use br_get_pvid helper

[Nikolay Aleksandrov]

The only place that accessed pvid directly outside of the bridge vlan code
was mst, change it to use the br_get_pvid helper.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
 net/bridge/br_mst.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
index 43a300ae6bfa..95e49ec8065e 100644
--- a/net/bridge/br_mst.c
+++ b/net/bridge/br_mst.c
@@ -86,7 +86,7 @@ static void br_mst_vlan_set_state(struct net_bridge_vlan_group *vg,
 	if (br_vlan_get_state(v) == state)
 		return;
 
-	if (v->vid == vg->pvid)
+	if (v->vid == br_get_pvid(vg))
 		br_vlan_set_pvid_state(vg, state);
 
 	br_vlan_set_state(v, state);
-- 
2.47.3

[PATCH net-next 4/9] net: bridge: vlan: annotate lockless vlan flags use

[Nikolay Aleksandrov]

Annotate vlan flags data races, they can be read lockless.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
 net/bridge/br_multicast.c |  2 +-
 net/bridge/br_netlink.c   |  6 +++---
 net/bridge/br_private.h   |  4 ++--
 net/bridge/br_vlan.c      | 19 +++++++++++--------
 4 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 3ef5d8bbf552..bbcaedf15ca1 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -912,7 +912,7 @@ static void __br_multicast_query_handle_vlan(struct net_bridge_mcast *brmctx,
 	else if (br_multicast_ctx_is_vlan(brmctx))
 		vlan = brmctx->vlan;
 
-	if (vlan && !(vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED)) {
+	if (vlan && !(READ_ONCE(vlan->flags) & BRIDGE_VLAN_INFO_UNTAGGED)) {
 		u16 vlan_proto;
 
 		if (br_vlan_get_proto(brmctx->br->dev, &vlan_proto) != 0)
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index b2cd4e39326d..62ce96d9ba32 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -41,7 +41,7 @@ static int __get_num_vlan_infos(struct net_bridge_vlan_group *vg,
 		if (v->vid == pvid)
 			flags |= BRIDGE_VLAN_INFO_PVID;
 
-		if (v->flags & BRIDGE_VLAN_INFO_UNTAGGED)
+		if (READ_ONCE(v->flags) & BRIDGE_VLAN_INFO_UNTAGGED)
 			flags |= BRIDGE_VLAN_INFO_UNTAGGED;
 
 		if (vid_range_start == 0) {
@@ -385,7 +385,7 @@ static int br_fill_ifvlaninfo_compressed(struct sk_buff *skb,
 		if (v->vid == pvid)
 			flags |= BRIDGE_VLAN_INFO_PVID;
 
-		if (v->flags & BRIDGE_VLAN_INFO_UNTAGGED)
+		if (READ_ONCE(v->flags) & BRIDGE_VLAN_INFO_UNTAGGED)
 			flags |= BRIDGE_VLAN_INFO_UNTAGGED;
 
 		if (vid_range_start == 0) {
@@ -437,7 +437,7 @@ static int br_fill_ifvlaninfo(struct sk_buff *skb,
 		if (v->vid == pvid)
 			vinfo.flags |= BRIDGE_VLAN_INFO_PVID;
 
-		if (v->flags & BRIDGE_VLAN_INFO_UNTAGGED)
+		if (READ_ONCE(v->flags) & BRIDGE_VLAN_INFO_UNTAGGED)
 			vinfo.flags |= BRIDGE_VLAN_INFO_UNTAGGED;
 
 		if (nla_put(skb, IFLA_BRIDGE_VLAN_INFO,
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 0efd2e79e255..96554d293d22 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -665,13 +665,13 @@ static inline int br_is_root_bridge(const struct net_bridge *br)
 /* check if a VLAN entry is global */
 static inline bool br_vlan_is_master(const struct net_bridge_vlan *v)
 {
-	return v->flags & BRIDGE_VLAN_INFO_MASTER;
+	return READ_ONCE(v->flags) & BRIDGE_VLAN_INFO_MASTER;
 }
 
 /* check if a VLAN entry is used by the bridge */
 static inline bool br_vlan_is_brentry(const struct net_bridge_vlan *v)
 {
-	return v->flags & BRIDGE_VLAN_INFO_BRENTRY;
+	return READ_ONCE(v->flags) & BRIDGE_VLAN_INFO_BRENTRY;
 }
 
 /* check if we should use the vlan entry, returns false if it's only context */
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index a53054fcc093..c8b2e3bfd42d 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -60,6 +60,7 @@ static bool __vlan_flags_update(struct net_bridge_vlan *v, u16 flags,
 				bool commit)
 {
 	struct net_bridge_vlan_group *vg;
+	u16 vlan_flags;
 	bool change;
 
 	if (br_vlan_is_master(v))
@@ -68,8 +69,9 @@ static bool __vlan_flags_update(struct net_bridge_vlan *v, u16 flags,
 		vg = nbp_vlan_group(v->port);
 
 	/* check if anything would be changed on commit */
+	vlan_flags = v->flags;
 	change = !!(flags & BRIDGE_VLAN_INFO_PVID) == !!(vg->pvid != v->vid) ||
-		 ((flags ^ v->flags) & BRIDGE_VLAN_INFO_UNTAGGED);
+		 ((flags ^ vlan_flags) & BRIDGE_VLAN_INFO_UNTAGGED);
 
 	if (!commit)
 		goto out;
@@ -80,9 +82,10 @@ static bool __vlan_flags_update(struct net_bridge_vlan *v, u16 flags,
 		__vlan_delete_pvid(vg, v->vid);
 
 	if (flags & BRIDGE_VLAN_INFO_UNTAGGED)
-		v->flags |= BRIDGE_VLAN_INFO_UNTAGGED;
+		vlan_flags |= BRIDGE_VLAN_INFO_UNTAGGED;
 	else
-		v->flags &= ~BRIDGE_VLAN_INFO_UNTAGGED;
+		vlan_flags &= ~BRIDGE_VLAN_INFO_UNTAGGED;
+	WRITE_ONCE(v->flags, vlan_flags);
 
 out:
 	return change;
@@ -413,7 +416,7 @@ static int __vlan_del(struct net_bridge_vlan *v)
 	}
 
 	if (br_vlan_should_use(v)) {
-		v->flags &= ~BRIDGE_VLAN_INFO_BRENTRY;
+		WRITE_ONCE(v->flags, v->flags & ~BRIDGE_VLAN_INFO_BRENTRY);
 		vg->num_vlans--;
 	}
 
@@ -522,7 +525,7 @@ struct sk_buff *br_handle_vlan(struct net_bridge *br,
 	 * hardware on each egress port as appropriate. So only strip the VLAN
 	 * header if forwarding offload is not being used.
 	 */
-	if (v->flags & BRIDGE_VLAN_INFO_UNTAGGED &&
+	if (READ_ONCE(v->flags) & BRIDGE_VLAN_INFO_UNTAGGED &&
 	    !br_switchdev_frame_uses_tx_fwd_offload(skb))
 		__vlan_hwaccel_clear_tag(skb);
 
@@ -753,7 +756,7 @@ static int br_vlan_add_existing(struct net_bridge *br,
 		}
 
 		refcount_inc(&vlan->refcnt);
-		vlan->flags |= BRIDGE_VLAN_INFO_BRENTRY;
+		WRITE_ONCE(vlan->flags, vlan->flags | BRIDGE_VLAN_INFO_BRENTRY);
 		vg->num_vlans++;
 		*changed = true;
 		br_multicast_toggle_one_vlan(vlan, true);
@@ -1489,7 +1492,7 @@ int br_vlan_fill_forward_path_mode(struct net_bridge *br,
 	if (!v || !br_vlan_should_use(v))
 		return -EINVAL;
 
-	if (!(v->flags & BRIDGE_VLAN_INFO_UNTAGGED))
+	if (!(READ_ONCE(v->flags) & BRIDGE_VLAN_INFO_UNTAGGED))
 		return 0;
 
 	if (path->bridge.vlan_mode == DEV_PATH_BR_VLAN_TAG)
@@ -1550,7 +1553,7 @@ int br_vlan_get_info_rcu(const struct net_device *dev, u16 vid,
 		return -ENOENT;
 
 	p_vinfo->vid = vid;
-	p_vinfo->flags = v->flags;
+	p_vinfo->flags = READ_ONCE(v->flags);
 	if (vid == br_get_pvid(vg))
 		p_vinfo->flags |= BRIDGE_VLAN_INFO_PVID;
 	return 0;
-- 
2.47.3

[PATCH net-next 5/9] net: bridge: vlan: annotate lockless use of private flags

[Nikolay Aleksandrov]

Annotate vlan private flags data races, they can be read lockless.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
 net/bridge/br_arp_nd_proxy.c |  6 ++++--
 net/bridge/br_multicast.c    | 16 ++++++++++------
 net/bridge/br_private.h      |  9 ++++++---
 net/bridge/br_vlan.c         |  2 +-
 net/bridge/br_vlan_options.c |  6 ++++--
 5 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c
index 87a40e2f1c50..b82fa6589ab9 100644
--- a/net/bridge/br_arp_nd_proxy.c
+++ b/net/bridge/br_arp_nd_proxy.c
@@ -521,7 +521,8 @@ bool br_is_neigh_suppress_enabled(const struct net_bridge_port *p, u16 vid)
 		v = br_vlan_find(vg, vid);
 		if (!v)
 			return false;
-		return !!(v->priv_flags & BR_VLFLAG_NEIGH_SUPPRESS_ENABLED);
+		return !!(READ_ONCE(v->priv_flags) &
+			  BR_VLFLAG_NEIGH_SUPPRESS_ENABLED);
 	}
 	return test_bit(BR_NEIGH_SUPPRESS_BIT, &p->flags);
 }
@@ -535,7 +536,8 @@ bool br_is_neigh_forward_grat_enabled(const struct net_bridge_port *p, u16 vid)
 		v = br_vlan_find(vg, vid);
 		if (!v)
 			return false;
-		return !!(v->priv_flags & BR_VLFLAG_NEIGH_FORWARD_GRAT_ENABLED);
+		return !!(READ_ONCE(v->priv_flags) &
+			  BR_VLFLAG_NEIGH_FORWARD_GRAT_ENABLED);
 	}
 	return test_bit(BR_NEIGH_FORWARD_GRAT_BIT, &p->flags);
 }
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index bbcaedf15ca1..cd984173320f 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -2172,7 +2172,7 @@ static void br_multicast_enable_port_ctx(struct net_bridge_mcast_port *pmctx)
 
 	spin_lock_bh(&br->multicast_lock);
 	if (br_multicast_port_ctx_is_vlan(pmctx) &&
-	    !(pmctx->vlan->priv_flags & BR_VLFLAG_MCAST_ENABLED)) {
+	    !(READ_ONCE(pmctx->vlan->priv_flags) & BR_VLFLAG_MCAST_ENABLED)) {
 		spin_unlock_bh(&br->multicast_lock);
 		return;
 	}
@@ -2209,7 +2209,7 @@ static void br_multicast_disable_port_ctx(struct net_bridge_mcast_port *pmctx)
 
 	spin_lock_bh(&br->multicast_lock);
 	if (br_multicast_port_ctx_is_vlan(pmctx) &&
-	    !(pmctx->vlan->priv_flags & BR_VLFLAG_MCAST_ENABLED)) {
+	    !(READ_ONCE(pmctx->vlan->priv_flags) & BR_VLFLAG_MCAST_ENABLED)) {
 		spin_unlock_bh(&br->multicast_lock);
 		return;
 	}
@@ -4083,7 +4083,8 @@ int br_multicast_rcv(struct net_bridge_mcast **brmctx,
 			*pmctx = &vlan->port_mcast_ctx;
 		}
 
-		if (!(masterv->priv_flags & BR_VLFLAG_GLOBAL_MCAST_ENABLED))
+		if (!(READ_ONCE(masterv->priv_flags) &
+		      BR_VLFLAG_GLOBAL_MCAST_ENABLED))
 			return 0;
 	}
 
@@ -4383,7 +4384,8 @@ void br_multicast_toggle_one_vlan(struct net_bridge_vlan *vlan, bool on)
 			return;
 
 		spin_lock_bh(&br->multicast_lock);
-		vlan->priv_flags ^= BR_VLFLAG_MCAST_ENABLED;
+		WRITE_ONCE(vlan->priv_flags, vlan->priv_flags ^
+					    BR_VLFLAG_MCAST_ENABLED);
 		spin_unlock_bh(&br->multicast_lock);
 
 		if (on)
@@ -4399,7 +4401,8 @@ void br_multicast_toggle_one_vlan(struct net_bridge_vlan *vlan, bool on)
 
 		br = vlan->port->br;
 		spin_lock_bh(&br->multicast_lock);
-		vlan->priv_flags ^= BR_VLFLAG_MCAST_ENABLED;
+		WRITE_ONCE(vlan->priv_flags, vlan->priv_flags ^
+					    BR_VLFLAG_MCAST_ENABLED);
 		if (on)
 			__br_multicast_enable_port_ctx(&vlan->port_mcast_ctx);
 		else
@@ -4477,7 +4480,8 @@ bool br_multicast_toggle_global_vlan(struct net_bridge_vlan *vlan, bool on)
 	if (on == !!(vlan->priv_flags & BR_VLFLAG_GLOBAL_MCAST_ENABLED))
 		return false;
 
-	vlan->priv_flags ^= BR_VLFLAG_GLOBAL_MCAST_ENABLED;
+	WRITE_ONCE(vlan->priv_flags, vlan->priv_flags ^
+				    BR_VLFLAG_GLOBAL_MCAST_ENABLED);
 	br_multicast_toggle_vlan(vlan, on);
 
 	return true;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 96554d293d22..c7b64b5da012 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1273,21 +1273,24 @@ br_multicast_ctx_vlan_global_disabled(const struct net_bridge_mcast *brmctx)
 {
 	return br_multicast_ctx_is_vlan(brmctx) &&
 	       (!br_opt_get(brmctx->br, BROPT_MCAST_VLAN_SNOOPING_ENABLED) ||
-		!(brmctx->vlan->priv_flags & BR_VLFLAG_GLOBAL_MCAST_ENABLED));
+		!(READ_ONCE(brmctx->vlan->priv_flags) &
+		  BR_VLFLAG_GLOBAL_MCAST_ENABLED));
 }
 
 static inline bool
 br_multicast_ctx_vlan_disabled(const struct net_bridge_mcast *brmctx)
 {
 	return br_multicast_ctx_is_vlan(brmctx) &&
-	       !(brmctx->vlan->priv_flags & BR_VLFLAG_MCAST_ENABLED);
+	       !(READ_ONCE(brmctx->vlan->priv_flags) &
+		 BR_VLFLAG_MCAST_ENABLED);
 }
 
 static inline bool
 br_multicast_port_ctx_vlan_disabled(const struct net_bridge_mcast_port *pmctx)
 {
 	return br_multicast_port_ctx_is_vlan(pmctx) &&
-	       !(pmctx->vlan->priv_flags & BR_VLFLAG_MCAST_ENABLED);
+	       !(READ_ONCE(pmctx->vlan->priv_flags) &
+		 BR_VLFLAG_MCAST_ENABLED);
 }
 
 static inline bool
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index c8b2e3bfd42d..102792f20a5e 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -1497,7 +1497,7 @@ int br_vlan_fill_forward_path_mode(struct net_bridge *br,
 
 	if (path->bridge.vlan_mode == DEV_PATH_BR_VLAN_TAG)
 		path->bridge.vlan_mode = DEV_PATH_BR_VLAN_KEEP;
-	else if (v->priv_flags & BR_VLFLAG_TAGGING_BY_SWITCHDEV)
+	else if (READ_ONCE(v->priv_flags) & BR_VLFLAG_TAGGING_BY_SWITCHDEV)
 		path->bridge.vlan_mode = DEV_PATH_BR_VLAN_UNTAG_HW;
 	else
 		path->bridge.vlan_mode = DEV_PATH_BR_VLAN_UNTAG;
diff --git a/net/bridge/br_vlan_options.c b/net/bridge/br_vlan_options.c
index cb0f556ff40d..bd049d268fe7 100644
--- a/net/bridge/br_vlan_options.c
+++ b/net/bridge/br_vlan_options.c
@@ -276,7 +276,8 @@ static int br_vlan_process_one_opts(const struct net_bridge *br,
 		}
 
 		if (val != enabled) {
-			v->priv_flags ^= BR_VLFLAG_NEIGH_SUPPRESS_ENABLED;
+			WRITE_ONCE(v->priv_flags, v->priv_flags ^
+				   BR_VLFLAG_NEIGH_SUPPRESS_ENABLED);
 			*changed = true;
 		}
 	}
@@ -292,7 +293,8 @@ static int br_vlan_process_one_opts(const struct net_bridge *br,
 		}
 
 		if (val != enabled) {
-			v->priv_flags ^= BR_VLFLAG_NEIGH_FORWARD_GRAT_ENABLED;
+			WRITE_ONCE(v->priv_flags, v->priv_flags ^
+				   BR_VLFLAG_NEIGH_FORWARD_GRAT_ENABLED);
 			*changed = true;
 		}
 	}
-- 
2.47.3

[PATCH net-next 6/9] net: bridge: vlan: annotate lockless use of num_vlans

[Nikolay Aleksandrov]

Annotate data races around vlan group's num_vlans, it can be read lockless.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
 net/bridge/br_netlink.c |  4 ++--
 net/bridge/br_vlan.c    | 10 +++++-----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 62ce96d9ba32..ae76df0de05a 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -81,7 +81,7 @@ static int br_get_num_vlan_infos(struct net_bridge_vlan_group *vg,
 		return 0;
 
 	if (filter_mask & RTEXT_FILTER_BRVLAN)
-		return vg->num_vlans;
+		return READ_ONCE(vg->num_vlans);
 
 	rcu_read_lock();
 	num_vlans = __get_num_vlan_infos(vg, filter_mask);
@@ -531,7 +531,7 @@ static int br_fill_ifinfo(struct sk_buff *skb,
 		else
 			vg = br_vlan_group_rcu(br);
 
-		if (!vg || !vg->num_vlans) {
+		if (!vg || !READ_ONCE(vg->num_vlans)) {
 			rcu_read_unlock();
 			goto done;
 		}
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 102792f20a5e..95187a607ec2 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -344,7 +344,7 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags,
 				goto out_filt;
 			}
 		}
-		vg->num_vlans++;
+		WRITE_ONCE(vg->num_vlans, vg->num_vlans + 1);
 	}
 
 	/* set the state before publishing */
@@ -367,7 +367,7 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags,
 out_fdb_insert:
 	if (br_vlan_should_use(v)) {
 		br_fdb_find_delete_local(br, p, dev->dev_addr, v->vid);
-		vg->num_vlans--;
+		WRITE_ONCE(vg->num_vlans, vg->num_vlans - 1);
 	}
 
 out_filt:
@@ -417,7 +417,7 @@ static int __vlan_del(struct net_bridge_vlan *v)
 
 	if (br_vlan_should_use(v)) {
 		WRITE_ONCE(v->flags, v->flags & ~BRIDGE_VLAN_INFO_BRENTRY);
-		vg->num_vlans--;
+		WRITE_ONCE(vg->num_vlans, vg->num_vlans - 1);
 	}
 
 	if (masterv != v) {
@@ -695,7 +695,7 @@ bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid)
 		return true;
 
 	vg = nbp_vlan_group_rcu(p);
-	if (!vg || !vg->num_vlans)
+	if (!vg || !READ_ONCE(vg->num_vlans))
 		return false;
 
 	if (!br_vlan_get_tag(skb, vid) && skb->vlan_proto != br->vlan_proto)
@@ -757,7 +757,7 @@ static int br_vlan_add_existing(struct net_bridge *br,
 
 		refcount_inc(&vlan->refcnt);
 		WRITE_ONCE(vlan->flags, vlan->flags | BRIDGE_VLAN_INFO_BRENTRY);
-		vg->num_vlans++;
+		WRITE_ONCE(vg->num_vlans, vg->num_vlans + 1);
 		*changed = true;
 		br_multicast_toggle_one_vlan(vlan, true);
 	}
-- 
2.47.3

[PATCH net-next 7/9] net: bridge: vlan: annotate lockless use of msti

[Nikolay Aleksandrov]

Annotate data races around vlan msti field, it can be read lockless.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
 net/bridge/br_mst.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
index 95e49ec8065e..76a5bf287578 100644
--- a/net/bridge/br_mst.c
+++ b/net/bridge/br_mst.c
@@ -123,7 +123,7 @@ int br_mst_set_state(struct net_bridge_port *p, u16 msti, u8 state,
 
 	err = 0;
 	list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
-		if (v->brvlan->msti != msti)
+		if (READ_ONCE(v->brvlan->msti) != msti)
 			continue;
 
 		br_mst_vlan_set_state(vg, v, state);
@@ -176,7 +176,7 @@ int br_mst_vlan_set_msti(struct net_bridge_vlan *mv, u16 msti)
 	if (err && err != -EOPNOTSUPP)
 		return err;
 
-	mv->msti = msti;
+	WRITE_ONCE(mv->msti, msti);
 
 	list_for_each_entry(p, &mv->br->port_list, list) {
 		vg = nbp_vlan_group(p);
@@ -249,7 +249,9 @@ size_t br_mst_info_size(const struct net_bridge_vlan_group *vg)
 	sz = nla_total_size(0);
 
 	list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
-		if (test_bit(v->brvlan->msti, seen))
+		u16 msti = READ_ONCE(v->brvlan->msti);
+
+		if (test_bit(msti, seen))
 			continue;
 
 		/* IFLA_BRIDGE_MST_ENTRY */
@@ -259,7 +261,7 @@ size_t br_mst_info_size(const struct net_bridge_vlan_group *vg)
 			/* IFLA_BRIDGE_MST_ENTRY_STATE */
 			nla_total_size(sizeof(u8));
 
-		__set_bit(v->brvlan->msti, seen);
+		__set_bit(msti, seen);
 	}
 
 	return sz;
-- 
2.47.3

[PATCH net-next 8/9] net: bridge: vlan: add missing tinfo.tunnel_id annotations

[Nikolay Aleksandrov]

When I annotated data races around tinfo.tunnel_id before, I missed a few
places (e.g. bridge notifications, rhashtable compare), so add them now.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
 net/bridge/br_netlink_tunnel.c | 12 ++++++------
 net/bridge/br_vlan_tunnel.c    |  2 +-
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/net/bridge/br_netlink_tunnel.c b/net/bridge/br_netlink_tunnel.c
index e7eceab5b515..58ec7bf1d8f5 100644
--- a/net/bridge/br_netlink_tunnel.c
+++ b/net/bridge/br_netlink_tunnel.c
@@ -29,8 +29,8 @@ static size_t __get_vlan_tinfo_size(void)
 bool vlan_tunid_inrange(const struct net_bridge_vlan *v_curr,
 			const struct net_bridge_vlan *v_last)
 {
-	__be32 tunid_curr = tunnel_id_to_key32(v_curr->tinfo.tunnel_id);
-	__be32 tunid_last = tunnel_id_to_key32(v_last->tinfo.tunnel_id);
+	__be32 tunid_curr = tunnel_id_to_key32(READ_ONCE(v_curr->tinfo.tunnel_id));
+	__be32 tunid_last = tunnel_id_to_key32(READ_ONCE(v_last->tinfo.tunnel_id));
 
 	return (be32_to_cpu(tunid_curr) - be32_to_cpu(tunid_last)) == 1;
 }
@@ -43,7 +43,7 @@ static int __get_num_vlan_tunnel_infos(struct net_bridge_vlan_group *vg)
 	/* Count number of vlan infos */
 	list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
 		/* only a context, bridge vlan not activated */
-		if (!br_vlan_should_use(v) || !v->tinfo.tunnel_id)
+		if (!br_vlan_should_use(v) || !READ_ONCE(v->tinfo.tunnel_id))
 			continue;
 
 		if (!vtbegin) {
@@ -124,19 +124,19 @@ static int br_fill_vlan_tinfo_range(struct sk_buff *skb,
 	if (vtend && (vtend->vid - vtbegin->vid) > 0) {
 		/* add range to skb */
 		err = br_fill_vlan_tinfo(skb, vtbegin->vid,
-					 vtbegin->tinfo.tunnel_id,
+					 READ_ONCE(vtbegin->tinfo.tunnel_id),
 					 BRIDGE_VLAN_INFO_RANGE_BEGIN);
 		if (err)
 			return err;
 
 		err = br_fill_vlan_tinfo(skb, vtend->vid,
-					 vtend->tinfo.tunnel_id,
+					 READ_ONCE(vtend->tinfo.tunnel_id),
 					 BRIDGE_VLAN_INFO_RANGE_END);
 		if (err)
 			return err;
 	} else {
 		err = br_fill_vlan_tinfo(skb, vtbegin->vid,
-					 vtbegin->tinfo.tunnel_id,
+					 READ_ONCE(vtbegin->tinfo.tunnel_id),
 					 0);
 		if (err)
 			return err;
diff --git a/net/bridge/br_vlan_tunnel.c b/net/bridge/br_vlan_tunnel.c
index 257cae9f1569..04751f15d708 100644
--- a/net/bridge/br_vlan_tunnel.c
+++ b/net/bridge/br_vlan_tunnel.c
@@ -22,7 +22,7 @@ static inline int br_vlan_tunid_cmp(struct rhashtable_compare_arg *arg,
 	const struct net_bridge_vlan *vle = ptr;
 	__be64 tunid = *(__be64 *)arg->key;
 
-	return vle->tinfo.tunnel_id != tunid;
+	return READ_ONCE(vle->tinfo.tunnel_id) != tunid;
 }
 
 static const struct rhashtable_params br_vlan_tunnel_rht_params = {
-- 
2.47.3

[PATCH net-next 9/9] net: bridge: vlan: use br_vlan_get_state to get vlan state

[Nikolay Aleksandrov]

The MST code can change the vlan state with only rcu, so use the helper
to get the state properly.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
 net/bridge/br_vlan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 95187a607ec2..72b75757ac85 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -40,7 +40,7 @@ static void __vlan_add_pvid(struct net_bridge_vlan_group *vg,
 	if (vg->pvid == v->vid)
 		return;
 
-	br_vlan_set_pvid_state(vg, v->state);
+	br_vlan_set_pvid_state(vg, br_vlan_get_state(v));
 	WRITE_ONCE(vg->pvid, v->vid);
 }
 
-- 
2.47.3

Re: [PATCH net-next 0/9] net: bridge: vlan: minor cleanups and annotations

[Nikolay Aleksandrov]

On 01/09/2026 15:07, Nikolay Aleksandrov wrote:
> Hi,
> In preparation for a complete vlan fast-path re-work, this set cleans up
> a few minor things - removing legacy code barriers that don't help,
>                       annotating lockless accesses and using proper helpers.
> No functional changes are intended. Sashiko will find many pre-existing
> problems, none of them are related to this set. I will try to fix
> everything pre-existing separately in -net, there will probably be a few
> critical items. So if there are missed places to annotate, or if there're
> actual functional changes, these obviously should be addressed in this set.
> 
> Thanks,
>   Nik
> 
> Nikolay Aleksandrov (9):
>    net: bridge: vlan: drop legacy memory barriers
>    net: bridge: vlan: annotate lockless pvid use
>    net: bridge: mst: use br_get_pvid helper
>    net: bridge: vlan: annotate lockless vlan flags use
>    net: bridge: vlan: annotate lockless use of private flags
>    net: bridge: vlan: annotate lockless use of num_vlans
>    net: bridge: vlan: annotate lockless use of msti
>    net: bridge: vlan: add missing tinfo.tunnel_id annotations
>    net: bridge: vlan: use br_vlan_get_state to get vlan state
> 
>   net/bridge/br_arp_nd_proxy.c   |  6 ++++--
>   net/bridge/br_mst.c            | 12 ++++++-----
>   net/bridge/br_multicast.c      | 18 ++++++++++------
>   net/bridge/br_netlink.c        | 10 ++++-----
>   net/bridge/br_netlink_tunnel.c | 12 +++++------
>   net/bridge/br_private.h        | 16 ++++++++------
>   net/bridge/br_vlan.c           | 39 +++++++++++++++++-----------------
>   net/bridge/br_vlan_options.c   |  6 ++++--
>   net/bridge/br_vlan_tunnel.c    |  2 +-
>   9 files changed, 67 insertions(+), 54 deletions(-)
> 

Me and Ido had a chat and he commented that patch 09 is far from done, I missed state
accesses outside of br_vlan.c, silly mistake. Anyway, I'll fix it up and post v2.

Cheers,
  Nik

---
pw-bot: cr