[PATCH net-next v5 2/6] vxlan: drop sock_lock

16 Jun 2025

We won't be able to sleep soon in vxlan_offload_rx_ports and won't be
able to grab sock_lock. Instead of having separate spinlock to
manage sockets, rely on rtnl lock. This is similar to how geneve
manages its sockets.
Signed-off-by: Stanislav Fomichev stfomichev@gmail.com
---
 drivers/net/vxlan/vxlan_core.c      | 35 ++++++++++++-----------------
 drivers/net/vxlan/vxlan_private.h   |  2 +-
 drivers/net/vxlan/vxlan_vnifilter.c | 18 ++++++---------
 3 files changed, 22 insertions(+), 33 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 97792de896b7..9d7249caf137 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1485,21 +1485,18 @@ static enum skb_drop_reason vxlan_snoop(struct net_device *dev,
static bool __vxlan_sock_release_prep(struct vxlan_sock *vs)
 {
-	struct vxlan_net *vn;
+	ASSERT_RTNL();
if (!vs)
    	return false;
    if (!refcount_dec_and_test(&vs->refcnt))
    	return false;
-	vn = net_generic(sock_net(vs->sock->sk), vxlan_net_id);
-	spin_lock(&vn->sock_lock);
    hlist_del_rcu(&vs->hlist);
    udp_tunnel_notify_del_rx_port(vs->sock,
    			      (vs->flags & VXLAN_F_GPE) ?
    			      UDP_TUNNEL_TYPE_VXLAN_GPE :
    			      UDP_TUNNEL_TYPE_VXLAN);
-	spin_unlock(&vn->sock_lock);
return true;
 }
@@ -2847,26 +2844,23 @@ static void vxlan_cleanup(struct timer_list *t)
static void vxlan_vs_del_dev(struct vxlan_dev *vxlan)
 {
-	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
+	ASSERT_RTNL();
-	spin_lock(&vn->sock_lock);
    hlist_del_init_rcu(&vxlan->hlist4.hlist);
 #if IS_ENABLED(CONFIG_IPV6)
    hlist_del_init_rcu(&vxlan->hlist6.hlist);
 #endif
-	spin_unlock(&vn->sock_lock);
 }
static void vxlan_vs_add_dev(struct vxlan_sock *vs, struct vxlan_dev *vxlan,
    		     struct vxlan_dev_node *node)
 {
-	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
    __be32 vni = vxlan->default_dst.remote_vni;
+	ASSERT_RTNL();
+
    node->vxlan = vxlan;
-	spin_lock(&vn->sock_lock);
    hlist_add_head_rcu(&node->hlist, vni_head(vs, vni));
-	spin_unlock(&vn->sock_lock);
 }
/* Setup stats when device is created */
@@ -3291,9 +3285,10 @@ static void vxlan_offload_rx_ports(struct net_device *dev, bool push)
    struct vxlan_net *vn = net_generic(net, vxlan_net_id);
    unsigned int i;
-	spin_lock(&vn->sock_lock);
+	ASSERT_RTNL();
+
    for (i = 0; i < PORT_HASH_SIZE; ++i) {
-		hlist_for_each_entry_rcu(vs, &vn->sock_list[i], hlist) {
+		hlist_for_each_entry(vs, &vn->sock_list[i], hlist) {
    		unsigned short type;
if (vs->flags & VXLAN_F_GPE)
@@ -3307,7 +3302,6 @@ static void vxlan_offload_rx_ports(struct net_device *dev, bool push)
    			udp_tunnel_drop_rx_port(dev, vs->sock, type);
    	}
    }
-	spin_unlock(&vn->sock_lock);
 }
/* Initialize the device structure. */
@@ -3537,12 +3531,13 @@ static struct vxlan_sock *vxlan_socket_create(struct net *net, bool ipv6,
    				      __be16 port, u32 flags,
    				      int ifindex)
 {
-	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
    struct vxlan_sock *vs;
    struct socket *sock;
    unsigned int h;
    struct udp_tunnel_sock_cfg tunnel_cfg;
+	ASSERT_RTNL();
+
    vs = kzalloc(sizeof(*vs), GFP_KERNEL);
    if (!vs)
    	return ERR_PTR(-ENOMEM);
@@ -3560,13 +3555,11 @@ static struct vxlan_sock *vxlan_socket_create(struct net *net, bool ipv6,
    refcount_set(&vs->refcnt, 1);
    vs->flags = (flags & VXLAN_F_RCV_FLAGS);
-	spin_lock(&vn->sock_lock);
    hlist_add_head_rcu(&vs->hlist, vs_head(net, port));
    udp_tunnel_notify_add_rx_port(sock,
    			      (vs->flags & VXLAN_F_GPE) ?
    			      UDP_TUNNEL_TYPE_VXLAN_GPE :
    			      UDP_TUNNEL_TYPE_VXLAN);
-	spin_unlock(&vn->sock_lock);
/* Mark socket as an encapsulation socket. */
    memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
@@ -3590,26 +3583,27 @@ static struct vxlan_sock *vxlan_socket_create(struct net *net, bool ipv6,
static int __vxlan_sock_add(struct vxlan_dev *vxlan, bool ipv6)
 {
-	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
    bool metadata = vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA;
    struct vxlan_sock *vs = NULL;
    struct vxlan_dev_node *node;
    int l3mdev_index = 0;
+	ASSERT_RTNL();
+
    if (vxlan->cfg.remote_ifindex)
    	l3mdev_index = l3mdev_master_upper_ifindex_by_index(
    		vxlan->net, vxlan->cfg.remote_ifindex);
if (!vxlan->cfg.no_share) {
-		spin_lock(&vn->sock_lock);
+		rcu_read_lock();
    	vs = vxlan_find_sock(vxlan->net, ipv6 ? AF_INET6 : AF_INET,
    			     vxlan->cfg.dst_port, vxlan->cfg.flags,
    			     l3mdev_index);
    	if (vs && !refcount_inc_not_zero(&vs->refcnt)) {
-			spin_unlock(&vn->sock_lock);
+			rcu_read_unlock();
    		return -EBUSY;
    	}
-		spin_unlock(&vn->sock_lock);
+		rcu_read_unlock();
    }
    if (!vs)
    	vs = vxlan_socket_create(vxlan->net, ipv6,
@@ -4875,7 +4869,6 @@ static __net_init int vxlan_init_net(struct net *net)
    unsigned int h;
INIT_LIST_HEAD(&vn->vxlan_list);
-	spin_lock_init(&vn->sock_lock);
    vn->nexthop_notifier_block.notifier_call = vxlan_nexthop_event;
for (h = 0; h < PORT_HASH_SIZE; ++h)
diff --git a/drivers/net/vxlan/vxlan_private.h b/drivers/net/vxlan/vxlan_private.h
index d328aed9feef..6c625fb29c6c 100644
--- a/drivers/net/vxlan/vxlan_private.h
+++ b/drivers/net/vxlan/vxlan_private.h
@@ -19,8 +19,8 @@ extern const struct rhashtable_params vxlan_vni_rht_params;
 /* per-network namespace private data for this module */
 struct vxlan_net {
    struct list_head  vxlan_list;
+	/* sock_list is protected by rtnl lock */
    struct hlist_head sock_list[PORT_HASH_SIZE];
-	spinlock_t	  sock_lock;
    struct notifier_block nexthop_notifier_block;
 };
diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c
index 186d0660669a..4ff56d9f8f28 100644
--- a/drivers/net/vxlan/vxlan_vnifilter.c
+++ b/drivers/net/vxlan/vxlan_vnifilter.c
@@ -40,11 +40,11 @@ static void vxlan_vs_add_del_vninode(struct vxlan_dev *vxlan,
    			     struct vxlan_vni_node *v,
    			     bool del)
 {
-	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
    struct vxlan_dev_node *node;
    struct vxlan_sock *vs;
-	spin_lock(&vn->sock_lock);
+	ASSERT_RTNL();
+
    if (del) {
    	if (!hlist_unhashed(&v->hlist4.hlist))
    		hlist_del_init_rcu(&v->hlist4.hlist);
@@ -52,7 +52,7 @@ static void vxlan_vs_add_del_vninode(struct vxlan_dev *vxlan,
    	if (!hlist_unhashed(&v->hlist6.hlist))
    		hlist_del_init_rcu(&v->hlist6.hlist);
 #endif
-		goto out;
+		return;
    }
#if IS_ENABLED(CONFIG_IPV6)
@@ -67,23 +67,21 @@ static void vxlan_vs_add_del_vninode(struct vxlan_dev *vxlan,
    	node = &v->hlist4;
    	hlist_add_head_rcu(&node->hlist, vni_head(vs, v->vni));
    }
-out:
-	spin_unlock(&vn->sock_lock);
 }
void vxlan_vs_add_vnigrp(struct vxlan_dev *vxlan,
    		 struct vxlan_sock *vs,
    		 bool ipv6)
 {
-	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
    struct vxlan_vni_group *vg = rtnl_dereference(vxlan->vnigrp);
    struct vxlan_vni_node *v, *tmp;
    struct vxlan_dev_node *node;
+	ASSERT_RTNL();
+
    if (!vg)
    	return;
-	spin_lock(&vn->sock_lock);
    list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
 #if IS_ENABLED(CONFIG_IPV6)
    	if (ipv6)
@@ -94,26 +92,24 @@ void vxlan_vs_add_vnigrp(struct vxlan_dev *vxlan,
    	node->vxlan = vxlan;
    	hlist_add_head_rcu(&node->hlist, vni_head(vs, v->vni));
    }
-	spin_unlock(&vn->sock_lock);
 }
void vxlan_vs_del_vnigrp(struct vxlan_dev *vxlan)
 {
    struct vxlan_vni_group *vg = rtnl_dereference(vxlan->vnigrp);
-	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
    struct vxlan_vni_node *v, *tmp;
+	ASSERT_RTNL();
+
    if (!vg)
    	return;
-	spin_lock(&vn->sock_lock);
    list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
    	hlist_del_init_rcu(&v->hlist4.hlist);
 #if IS_ENABLED(CONFIG_IPV6)
    	hlist_del_init_rcu(&v->hlist6.hlist);
 #endif
    }
-	spin_unlock(&vn->sock_lock);
 }
static void vxlan_vnifilter_stats_get(const struct vxlan_vni_node *vninode,
-- 
2.49.0



    

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[PATCH net-next v5 2/6] vxlan: drop sock_lock