From: Nikolay Aleksandrov <razor@blackwall.org>
To: netdev@vger.kernel.org
Cc: idosch@nvidia.com, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, horms@kernel.org,
bridge@lists.linux.dev, Nikolay Aleksandrov <razor@blackwall.org>
Subject: [PATCH net-next 6/9] net: bridge: vlan: annotate lockless use of num_vlans
Date: Tue, 1 Sep 2026 15:07:18 +0300 [thread overview]
Message-ID: <20260901120721.747908-7-razor@blackwall.org> (raw)
In-Reply-To: <20260901120721.747908-1-razor@blackwall.org>
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
next prev parent reply other threads:[~2026-09-01 12:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-01 12:07 [PATCH net-next 0/9] net: bridge: vlan: minor cleanups and annotations Nikolay Aleksandrov
2026-09-01 12:07 ` [PATCH net-next 1/9] net: bridge: vlan: drop legacy memory barriers Nikolay Aleksandrov
2026-09-01 12:07 ` [PATCH net-next 2/9] net: bridge: vlan: annotate lockless pvid use Nikolay Aleksandrov
2026-09-01 12:07 ` [PATCH net-next 3/9] net: bridge: mst: use br_get_pvid helper Nikolay Aleksandrov
2026-09-01 12:07 ` [PATCH net-next 4/9] net: bridge: vlan: annotate lockless vlan flags use Nikolay Aleksandrov
2026-09-01 12:07 ` [PATCH net-next 5/9] net: bridge: vlan: annotate lockless use of private flags Nikolay Aleksandrov
2026-09-01 12:07 ` Nikolay Aleksandrov [this message]
2026-09-01 12:07 ` [PATCH net-next 7/9] net: bridge: vlan: annotate lockless use of msti Nikolay Aleksandrov
2026-09-01 12:07 ` [PATCH net-next 8/9] net: bridge: vlan: add missing tinfo.tunnel_id annotations Nikolay Aleksandrov
2026-09-01 12:07 ` [PATCH net-next 9/9] net: bridge: vlan: use br_vlan_get_state to get vlan state Nikolay Aleksandrov
2026-09-02 17:22 ` [PATCH net-next 0/9] net: bridge: vlan: minor cleanups and annotations Nikolay Aleksandrov
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