vxlan: drop sock_lock

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>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20250616162117.287806-3-stfomichev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index a6cc1de4d8b85ba9a15f989cc8f7fab56ebad47e..bcde95cb2a2ec174007e36d7906385d408b6f704 100644 (file)
--- 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;
 }
@@ -2857,26 +2854,23 @@ 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 */
@@ -3301,9 +3295,10 @@ 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)
@@ -3317,7 +3312,6 @@ 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. */
@@ -3548,12 +3542,13 @@ 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);
@@ -3571,13 +3566,11 @@ 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));
@@ -3601,26 +3594,27 @@ 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,
@@ -4894,7 +4888,6 @@ 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 d328aed9feefdd91c4bda53ef81ccf26ce9336ad..6c625fb29c6cea639cf75e7f1a5aa3d1c2ae08e7 100644 (file)
--- 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 186d0660669aab1d13f793d45e6d7115ce33ff01..4ff56d9f8f2822be9a28902e201820fd039be3df 100644 (file)
--- 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,