[PATCH net-next v3 2/2] 8021q: publish vlan_devices_arrays entries with acquire/release
From: Jinjie Ruan <hidden>
Date: 2026-09-02 07:32:47
Also in:
lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Replace the smp_wmb()/smp_rmb() barrier pair with smp_store_release()/smp_load_acquire() on vg->vlan_devices_arrays[pidx][vidx]. vlan_group_prealloc_vid() publishes the array pointer via release; __vlan_group_get_device() acquires it before accessing the array, ensuring the allocated entries are visible. No functional change intended. Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Simon Horman <horms@kernel.org> Cc: Nicolai Buchwitz <redacted> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Hangbin Liu <redacted> Cc: Kuniyuki Iwashima <kuniyu@google.com> Assisted-by: DeepSeek:DeepSeek-V3 Signed-off-by: Jinjie Ruan <redacted> --- net/8021q/vlan.c | 6 ++---- net/8021q/vlan.h | 8 +++----- 2 files changed, 5 insertions(+), 9 deletions(-)
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 6df80cad40a2..ec9a7cc8afc7 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c@@ -70,10 +70,8 @@ static int vlan_group_prealloc_vid(struct vlan_group *vg, if (array == NULL) return -ENOBUFS; - /* paired with smp_rmb() in __vlan_group_get_device() */ - smp_wmb(); - - vg->vlan_devices_arrays[pidx][vidx] = array; + /* paired with smp_load_acquire() in __vlan_group_get_device() */ + smp_store_release(&vg->vlan_devices_arrays[pidx][vidx], array); return 0; }
diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h
index 3cb4c8294130..d874ab323d32 100644
--- a/net/8021q/vlan.h
+++ b/net/8021q/vlan.h@@ -56,11 +56,9 @@ static inline struct net_device *__vlan_group_get_device(struct vlan_group *vg, { struct net_device __rcu **array; - array = vg->vlan_devices_arrays[pidx] - [vlan_id / VLAN_GROUP_ARRAY_PART_LEN]; - - /* paired with smp_wmb() in vlan_group_prealloc_vid() */ - smp_rmb(); + /* Pairs with smp_store_release() in vlan_group_prealloc_vid() */ + array = smp_load_acquire(&vg->vlan_devices_arrays[pidx] + [vlan_id / VLAN_GROUP_ARRAY_PART_LEN]); return array ? rcu_dereference_raw(array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN]) : NULL; }
--
2.34.1