* [PATCH net-next 1/2] geneve: convert config to RCU-protected pointer
2026-07-01 12:04 [PATCH net-next 0/2] geneve: make geneve_fill_info() RTNL-less Eric Dumazet
@ 2026-07-01 12:04 ` Eric Dumazet
2026-07-01 12:04 ` [PATCH net-next 2/2] geneve: make geneve_fill_info() RTNL independent Eric Dumazet
1 sibling, 0 replies; 3+ messages in thread
From: Eric Dumazet @ 2026-07-01 12:04 UTC (permalink / raw)
To: David S . Miller, Jakub Kicinski, Paolo Abeni
Cc: Simon Horman, Kuniyuki Iwashima, Andrew Lunn, netdev,
eric.dumazet, Eric Dumazet
geneve_changelink() currently updates configuration by copying it over
the old one using memcpy() under RTNL, forcing data path pause via
geneve_quiesce() and synchronize_net() to avoid reading torn values.
Convert geneve->cfg to an RCU-protected pointer, allowing lockless
and safe reads under RCU read lock without synchronization overhead.
Key changes:
- Introduced geneve_config_alloc/free() helpers for lifecycle.
- geneve_configure() allocates config and publishes it via RCU.
- geneve_changelink() performs RCU swap; old config is freed via call_rcu_hurry().
- Allocates new dst_cache during changelink to prevent pcpu sharing.
- Removed geneve_quiesce/unquiesce() and synchronize_net() from changelink.
- Added rcu_barrier() to module exit to wait for pending callbacks.
- Updated data path to use rcu_dereference().
- Updated geneve_fill_info() to use rtnl_dereference() for now.
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
drivers/net/geneve.c | 366 +++++++++++++++++++++++++------------------
1 file changed, 210 insertions(+), 156 deletions(-)
diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 396e1a113cd49e9a43bfe6c7cd78f15ca8963906..c777c1a1fa930d74768a659e16380d719f12a6b2 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -82,6 +82,7 @@ struct geneve_config {
u16 port_min;
u16 port_max;
+ struct rcu_head rcu;
/* Must be last --ends in a flexible-array member. */
struct ip_tunnel_info info;
};
@@ -100,7 +101,7 @@ struct geneve_dev {
#endif
struct list_head next; /* geneve's per namespace list */
struct gro_cells gro_cells;
- struct geneve_config cfg;
+ struct geneve_config __rcu *cfg;
};
struct geneve_sock {
@@ -182,8 +183,10 @@ static struct geneve_dev *geneve_lookup(struct geneve_sock *gs,
hash = geneve_net_vni_hash(vni);
vni_list_head = &gs->vni_list[hash];
hlist_for_each_entry_rcu(node, vni_list_head, hlist) {
- if (eq_tun_id_and_vni((u8 *)&node->geneve->cfg.info.key.tun_id, vni) &&
- addr == node->geneve->cfg.info.key.u.ipv4.dst)
+ const struct geneve_config *cfg = rcu_dereference(node->geneve->cfg);
+
+ if (eq_tun_id_and_vni((u8 *)&cfg->info.key.tun_id, vni) &&
+ addr == cfg->info.key.u.ipv4.dst)
return node->geneve;
}
return NULL;
@@ -201,8 +204,10 @@ static struct geneve_dev *geneve6_lookup(struct geneve_sock *gs,
hash = geneve_net_vni_hash(vni);
vni_list_head = &gs->vni_list[hash];
hlist_for_each_entry_rcu(node, vni_list_head, hlist) {
- if (eq_tun_id_and_vni((u8 *)&node->geneve->cfg.info.key.tun_id, vni) &&
- ipv6_addr_equal(&addr6, &node->geneve->cfg.info.key.u.ipv6.dst))
+ const struct geneve_config *cfg = rcu_dereference(node->geneve->cfg);
+
+ if (eq_tun_id_and_vni((u8 *)&cfg->info.key.tun_id, vni) &&
+ ipv6_addr_equal(&addr6, &cfg->info.key.u.ipv6.dst))
return node->geneve;
}
return NULL;
@@ -386,11 +391,6 @@ static int geneve_init(struct net_device *dev)
if (err)
return err;
- err = dst_cache_init(&geneve->cfg.info.dst_cache, GFP_KERNEL);
- if (err) {
- gro_cells_destroy(&geneve->gro_cells);
- return err;
- }
netdev_lockdep_set_classes(dev);
return 0;
}
@@ -399,7 +399,6 @@ static void geneve_uninit(struct net_device *dev)
{
struct geneve_dev *geneve = netdev_priv(dev);
- dst_cache_destroy(&geneve->cfg.info.dst_cache);
gro_cells_destroy(&geneve->gro_cells);
}
@@ -675,10 +674,14 @@ static int geneve_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
inner_proto = geneveh->proto_type;
- if (unlikely((!geneve->cfg.inner_proto_inherit &&
- inner_proto != htons(ETH_P_TEB)))) {
- dev_dstats_rx_dropped(geneve->dev);
- goto drop;
+ {
+ const struct geneve_config *cfg = rcu_dereference(geneve->cfg);
+
+ if (unlikely(!cfg || (!cfg->inner_proto_inherit &&
+ inner_proto != htons(ETH_P_TEB)))) {
+ dev_dstats_rx_dropped(geneve->dev);
+ goto drop;
+ }
}
opts_len = geneveh->opt_len * 4;
@@ -762,9 +765,10 @@ static int geneve_udp_encap_err_lookup(struct sock *sk, struct sk_buff *skb)
}
static struct sock *geneve_create_sock(struct net *net,
- struct geneve_dev *geneve, bool ipv6)
+ struct geneve_dev *geneve,
+ const struct geneve_config *cfg, bool ipv6)
{
- struct ip_tunnel_info *info = &geneve->cfg.info;
+ const struct ip_tunnel_info *info = &cfg->info;
struct udp_port_cfg udp_conf;
struct socket *sock;
int err;
@@ -775,7 +779,7 @@ static struct sock *geneve_create_sock(struct net *net,
if (ipv6) {
udp_conf.family = AF_INET6;
udp_conf.ipv6_v6only = 1;
- udp_conf.use_udp6_rx_checksums = geneve->cfg.use_udp6_rx_checksums;
+ udp_conf.use_udp6_rx_checksums = cfg->use_udp6_rx_checksums;
udp_conf.local_ip6 = info->key.u.ipv6.src;
} else
#endif
@@ -991,7 +995,8 @@ static int geneve_gro_complete(struct sock *sk, struct sk_buff *skb,
/* Create new listen socket if needed */
static struct geneve_sock *geneve_socket_create(struct net *net,
- struct geneve_dev *geneve, bool ipv6)
+ struct geneve_dev *geneve,
+ const struct geneve_config *cfg, bool ipv6)
{
struct geneve_net *gn = net_generic(net, geneve_net_id);
struct udp_tunnel_sock_cfg tunnel_cfg;
@@ -1003,7 +1008,7 @@ static struct geneve_sock *geneve_socket_create(struct net *net,
if (!gs)
return ERR_PTR(-ENOMEM);
- sk = geneve_create_sock(net, geneve, ipv6);
+ sk = geneve_create_sock(net, geneve, cfg, ipv6);
if (IS_ERR(sk)) {
kfree(gs);
return ERR_CAST(sk);
@@ -1060,12 +1065,13 @@ static void geneve_sock_release(struct geneve_dev *geneve)
}
static struct geneve_sock *geneve_find_sock(struct net *net,
- struct geneve_dev *geneve, bool ipv6)
+ struct geneve_dev *geneve,
+ const struct geneve_config *cfg, bool ipv6)
{
struct geneve_net *gn = net_generic(net, geneve_net_id);
- struct ip_tunnel_info *info = &geneve->cfg.info;
+ const struct ip_tunnel_info *info = &cfg->info;
sa_family_t family = ipv6 ? AF_INET6 : AF_INET;
- bool gro_hint = geneve->cfg.gro_hint;
+ bool gro_hint = cfg->gro_hint;
__be16 dst_port = info->key.tp_dst;
struct geneve_sock *gs;
@@ -1095,7 +1101,8 @@ static struct geneve_sock *geneve_find_sock(struct net *net,
return NULL;
}
-static int geneve_sock_add(struct geneve_dev *geneve, bool ipv6)
+static int geneve_sock_add(struct geneve_dev *geneve,
+ const struct geneve_config *cfg, bool ipv6)
{
struct net *net = geneve->net;
struct geneve_dev_node *node;
@@ -1103,19 +1110,19 @@ static int geneve_sock_add(struct geneve_dev *geneve, bool ipv6)
__u8 vni[3];
__u32 hash;
- gs = geneve_find_sock(net, geneve, ipv6);
+ gs = geneve_find_sock(net, geneve, cfg, ipv6);
if (gs) {
gs->refcnt++;
goto out;
}
- gs = geneve_socket_create(net, geneve, ipv6);
+ gs = geneve_socket_create(net, geneve, cfg, ipv6);
if (IS_ERR(gs))
return PTR_ERR(gs);
out:
- gs->collect_md = geneve->cfg.collect_md;
- gs->gro_hint = geneve->cfg.gro_hint;
+ gs->collect_md = cfg->collect_md;
+ gs->gro_hint = cfg->gro_hint;
#if IS_ENABLED(CONFIG_IPV6)
if (ipv6) {
rcu_assign_pointer(geneve->sock6, gs);
@@ -1128,7 +1135,7 @@ static int geneve_sock_add(struct geneve_dev *geneve, bool ipv6)
}
node->geneve = geneve;
- tunnel_id_to_vni(geneve->cfg.info.key.tun_id, vni);
+ tunnel_id_to_vni(cfg->info.key.tun_id, vni);
hash = geneve_net_vni_hash(vni);
hlist_add_head_rcu(&node->hlist, &gs->vni_list[hash]);
return 0;
@@ -1137,21 +1144,22 @@ static int geneve_sock_add(struct geneve_dev *geneve, bool ipv6)
static int geneve_open(struct net_device *dev)
{
struct geneve_dev *geneve = netdev_priv(dev);
- bool dualstack = geneve->cfg.dualstack;
+ const struct geneve_config *cfg = rtnl_dereference(geneve->cfg);
+ bool dualstack = cfg->dualstack;
bool ipv4, ipv6;
int ret = 0;
- ipv6 = geneve->cfg.info.mode & IP_TUNNEL_INFO_IPV6 || dualstack;
+ ipv6 = cfg->info.mode & IP_TUNNEL_INFO_IPV6 || dualstack;
ipv4 = !ipv6 || dualstack;
#if IS_ENABLED(CONFIG_IPV6)
if (ipv6) {
- ret = geneve_sock_add(geneve, true);
+ ret = geneve_sock_add(geneve, cfg, true);
if (ret < 0 && ret != -EAFNOSUPPORT)
ipv4 = false;
}
#endif
if (ipv4)
- ret = geneve_sock_add(geneve, false);
+ ret = geneve_sock_add(geneve, cfg, false);
if (ret < 0)
geneve_sock_release(geneve);
@@ -1189,6 +1197,7 @@ static void geneve_build_header(struct genevehdr *geneveh,
}
static int geneve_build_gro_hint_opt(const struct geneve_dev *geneve,
+ const struct geneve_config *cfg,
struct sk_buff *skb)
{
struct geneve_skb_cb *cb = GENEVE_SKB_CB(skb);
@@ -1201,7 +1210,7 @@ static int geneve_build_gro_hint_opt(const struct geneve_dev *geneve,
cb->gro_hint_len = 0;
/* Try to add the GRO hint only in case of double encap. */
- if (!geneve->cfg.gro_hint || !skb->encapsulation)
+ if (!cfg->gro_hint || !skb->encapsulation)
return 0;
/*
@@ -1262,10 +1271,11 @@ static void geneve_put_gro_hint_opt(struct genevehdr *gnvh, int opt_size,
static int geneve_build_skb(struct dst_entry *dst, struct sk_buff *skb,
const struct ip_tunnel_info *info,
- const struct geneve_dev *geneve, int ip_hdr_len)
+ const struct geneve_dev *geneve,
+ const struct geneve_config *cfg, int ip_hdr_len)
{
bool udp_sum = test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
- bool inner_proto_inherit = geneve->cfg.inner_proto_inherit;
+ bool inner_proto_inherit = cfg->inner_proto_inherit;
bool xnet = !net_eq(geneve->net, dev_net(geneve->dev));
struct geneve_skb_cb *cb = GENEVE_SKB_CB(skb);
struct genevehdr *gnvh;
@@ -1306,14 +1316,14 @@ static int geneve_build_skb(struct dst_entry *dst, struct sk_buff *skb,
}
static u8 geneve_get_dsfield(struct sk_buff *skb, struct net_device *dev,
+ const struct geneve_config *cfg,
const struct ip_tunnel_info *info,
bool *use_cache)
{
- struct geneve_dev *geneve = netdev_priv(dev);
u8 dsfield;
dsfield = info->key.tos;
- if (dsfield == 1 && !geneve->cfg.collect_md) {
+ if (cfg && dsfield == 1 && !cfg->collect_md) {
dsfield = ip_tunnel_get_dsfield(ip_hdr(skb), skb);
*use_cache = false;
}
@@ -1323,6 +1333,7 @@ static u8 geneve_get_dsfield(struct sk_buff *skb, struct net_device *dev,
static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
struct geneve_dev *geneve,
+ const struct geneve_config *cfg,
const struct ip_tunnel_info *info)
{
struct geneve_sock *gs4 = rcu_dereference(geneve->sock4);
@@ -1335,35 +1346,35 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
__be16 sport;
int err;
- if (skb_vlan_inet_prepare(skb, geneve->cfg.inner_proto_inherit))
+ if (skb_vlan_inet_prepare(skb, cfg->inner_proto_inherit))
return -EINVAL;
if (!gs4)
return -EIO;
use_cache = ip_tunnel_dst_cache_usable(skb, info);
- tos = geneve_get_dsfield(skb, dev, info, &use_cache);
+ tos = geneve_get_dsfield(skb, dev, cfg, info, &use_cache);
sport = udp_flow_src_port(geneve->net, skb,
- geneve->cfg.port_min,
- geneve->cfg.port_max, true);
+ cfg->port_min,
+ cfg->port_max, true);
rt = udp_tunnel_dst_lookup(skb, dev, geneve->net, 0, &saddr,
&info->key,
- sport, geneve->cfg.info.key.tp_dst, tos,
+ sport, cfg->info.key.tp_dst, tos,
use_cache ?
(struct dst_cache *)&info->dst_cache : NULL);
if (IS_ERR(rt))
return PTR_ERR(rt);
- if (geneve->cfg.info.key.u.ipv4.src &&
- saddr != geneve->cfg.info.key.u.ipv4.src) {
+ if (cfg->info.key.u.ipv4.src &&
+ saddr != cfg->info.key.u.ipv4.src) {
dst_release(&rt->dst);
return -EADDRNOTAVAIL;
}
err = skb_tunnel_check_pmtu(skb, &rt->dst,
GENEVE_IPV4_HLEN + info->options_len +
- geneve_build_gro_hint_opt(geneve, skb),
+ geneve_build_gro_hint_opt(geneve, cfg, skb),
netif_is_any_bridge_port(dev));
if (err < 0) {
dst_release(&rt->dst);
@@ -1397,21 +1408,21 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
}
tos = ip_tunnel_ecn_encap(tos, ip_hdr(skb), skb);
- if (geneve->cfg.collect_md) {
+ if (cfg->collect_md) {
ttl = key->ttl;
df = test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, key->tun_flags) ?
htons(IP_DF) : 0;
} else {
- if (geneve->cfg.ttl_inherit)
+ if (cfg->ttl_inherit)
ttl = ip_tunnel_get_ttl(ip_hdr(skb), skb);
else
ttl = key->ttl;
ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);
- if (geneve->cfg.df == GENEVE_DF_SET) {
+ if (cfg->df == GENEVE_DF_SET) {
df = htons(IP_DF);
- } else if (geneve->cfg.df == GENEVE_DF_INHERIT) {
+ } else if (cfg->df == GENEVE_DF_INHERIT) {
struct ethhdr *eth = skb_eth_hdr(skb);
if (ntohs(eth->h_proto) == ETH_P_IPV6) {
@@ -1425,13 +1436,13 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
}
}
- err = geneve_build_skb(&rt->dst, skb, info, geneve,
+ err = geneve_build_skb(&rt->dst, skb, info, geneve, cfg,
sizeof(struct iphdr));
if (unlikely(err))
return err;
udp_tunnel_xmit_skb(rt, gs4->sk, skb, saddr, info->key.u.ipv4.dst,
- tos, ttl, df, sport, geneve->cfg.info.key.tp_dst,
+ tos, ttl, df, sport, cfg->info.key.tp_dst,
!net_eq(geneve->net, dev_net(geneve->dev)),
!test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags),
0);
@@ -1441,6 +1452,7 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
#if IS_ENABLED(CONFIG_IPV6)
static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
struct geneve_dev *geneve,
+ const struct geneve_config *cfg,
const struct ip_tunnel_info *info)
{
struct geneve_sock *gs6 = rcu_dereference(geneve->sock6);
@@ -1452,35 +1464,35 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
__be16 sport;
int err;
- if (skb_vlan_inet_prepare(skb, geneve->cfg.inner_proto_inherit))
+ if (skb_vlan_inet_prepare(skb, cfg->inner_proto_inherit))
return -EINVAL;
if (!gs6)
return -EIO;
use_cache = ip_tunnel_dst_cache_usable(skb, info);
- prio = geneve_get_dsfield(skb, dev, info, &use_cache);
+ prio = geneve_get_dsfield(skb, dev, cfg, info, &use_cache);
sport = udp_flow_src_port(geneve->net, skb,
- geneve->cfg.port_min,
- geneve->cfg.port_max, true);
+ cfg->port_min,
+ cfg->port_max, true);
dst = udp_tunnel6_dst_lookup(skb, dev, geneve->net, gs6->sk, 0,
&saddr, key, sport,
- geneve->cfg.info.key.tp_dst, prio,
+ cfg->info.key.tp_dst, prio,
use_cache ?
(struct dst_cache *)&info->dst_cache : NULL);
if (IS_ERR(dst))
return PTR_ERR(dst);
- if (!ipv6_addr_any(&geneve->cfg.info.key.u.ipv6.src) &&
- !ipv6_addr_equal(&saddr, &geneve->cfg.info.key.u.ipv6.src)) {
+ if (!ipv6_addr_any(&cfg->info.key.u.ipv6.src) &&
+ !ipv6_addr_equal(&saddr, &cfg->info.key.u.ipv6.src)) {
dst_release(dst);
return -EADDRNOTAVAIL;
}
err = skb_tunnel_check_pmtu(skb, dst,
GENEVE_IPV6_HLEN + info->options_len +
- geneve_build_gro_hint_opt(geneve, skb),
+ geneve_build_gro_hint_opt(geneve, cfg, skb),
netif_is_any_bridge_port(dev));
if (err < 0) {
dst_release(dst);
@@ -1513,22 +1525,22 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
}
prio = ip_tunnel_ecn_encap(prio, ip_hdr(skb), skb);
- if (geneve->cfg.collect_md) {
+ if (cfg->collect_md) {
ttl = key->ttl;
} else {
- if (geneve->cfg.ttl_inherit)
+ if (cfg->ttl_inherit)
ttl = ip_tunnel_get_ttl(ip_hdr(skb), skb);
else
ttl = key->ttl;
ttl = ttl ? : ip6_dst_hoplimit(dst);
}
- err = geneve_build_skb(dst, skb, info, geneve, sizeof(struct ipv6hdr));
+ err = geneve_build_skb(dst, skb, info, geneve, cfg, sizeof(struct ipv6hdr));
if (unlikely(err))
return err;
udp_tunnel6_xmit_skb(dst, gs6->sk, skb, dev,
&saddr, &key->u.ipv6.dst, prio, ttl,
- info->key.label, sport, geneve->cfg.info.key.tp_dst,
+ info->key.label, sport, cfg->info.key.tp_dst,
!test_bit(IP_TUNNEL_CSUM_BIT,
info->key.tun_flags),
0);
@@ -1539,28 +1551,36 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
static netdev_tx_t geneve_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct geneve_dev *geneve = netdev_priv(dev);
- struct ip_tunnel_info *info = NULL;
+ const struct ip_tunnel_info *info = NULL;
+ const struct geneve_config *cfg;
int err;
- if (geneve->cfg.collect_md) {
+ rcu_read_lock();
+ cfg = rcu_dereference(geneve->cfg);
+ if (unlikely(!cfg)) {
+ err = -ENODEV;
+ goto tx_err;
+ }
+
+ if (cfg->collect_md) {
info = skb_tunnel_info(skb);
if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
netdev_dbg(dev, "no tunnel metadata\n");
dev_kfree_skb(skb);
dev_dstats_tx_dropped(dev);
+ rcu_read_unlock();
return NETDEV_TX_OK;
}
} else {
- info = &geneve->cfg.info;
+ info = &cfg->info;
}
- rcu_read_lock();
#if IS_ENABLED(CONFIG_IPV6)
if (info->mode & IP_TUNNEL_INFO_IPV6)
- err = geneve6_xmit_skb(skb, dev, geneve, info);
+ err = geneve6_xmit_skb(skb, dev, geneve, cfg, info);
else
#endif
- err = geneve_xmit_skb(skb, dev, geneve, info);
+ err = geneve_xmit_skb(skb, dev, geneve, cfg, info);
rcu_read_unlock();
if (likely(!err))
@@ -1576,6 +1596,12 @@ static netdev_tx_t geneve_xmit(struct sk_buff *skb, struct net_device *dev)
DEV_STATS_INC(dev, tx_errors);
return NETDEV_TX_OK;
+
+tx_err:
+ rcu_read_unlock();
+ dev_kfree_skb(skb);
+ DEV_STATS_INC(dev, tx_errors);
+ return NETDEV_TX_OK;
}
static int geneve_change_mtu(struct net_device *dev, int new_mtu)
@@ -1593,8 +1619,13 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
{
struct ip_tunnel_info *info = skb_tunnel_info(skb);
struct geneve_dev *geneve = netdev_priv(dev);
+ const struct geneve_config *cfg;
__be16 sport;
+ cfg = rcu_dereference(geneve->cfg);
+ if (unlikely(!cfg))
+ return -ENODEV;
+
if (ip_tunnel_info_af(info) == AF_INET) {
struct rtable *rt;
struct geneve_sock *gs4 = rcu_dereference(geneve->sock4);
@@ -1606,14 +1637,14 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
return -EIO;
use_cache = ip_tunnel_dst_cache_usable(skb, info);
- tos = geneve_get_dsfield(skb, dev, info, &use_cache);
+ tos = geneve_get_dsfield(skb, dev, cfg, info, &use_cache);
sport = udp_flow_src_port(geneve->net, skb,
- geneve->cfg.port_min,
- geneve->cfg.port_max, true);
+ cfg->port_min,
+ cfg->port_max, true);
rt = udp_tunnel_dst_lookup(skb, dev, geneve->net, 0, &saddr,
&info->key,
- sport, geneve->cfg.info.key.tp_dst,
+ sport, cfg->info.key.tp_dst,
tos,
use_cache ? &info->dst_cache : NULL);
if (IS_ERR(rt))
@@ -1633,14 +1664,14 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
return -EIO;
use_cache = ip_tunnel_dst_cache_usable(skb, info);
- prio = geneve_get_dsfield(skb, dev, info, &use_cache);
+ prio = geneve_get_dsfield(skb, dev, cfg, info, &use_cache);
sport = udp_flow_src_port(geneve->net, skb,
- geneve->cfg.port_min,
- geneve->cfg.port_max, true);
+ cfg->port_min,
+ cfg->port_max, true);
dst = udp_tunnel6_dst_lookup(skb, dev, geneve->net, gs6->sk, 0,
&saddr, &info->key, sport,
- geneve->cfg.info.key.tp_dst, prio,
+ cfg->info.key.tp_dst, prio,
use_cache ? &info->dst_cache : NULL);
if (IS_ERR(dst))
return PTR_ERR(dst);
@@ -1653,7 +1684,7 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
}
info->key.tp_src = sport;
- info->key.tp_dst = geneve->cfg.info.key.tp_dst;
+ info->key.tp_dst = cfg->info.key.tp_dst;
return 0;
}
@@ -1709,7 +1740,49 @@ static void geneve_offload_rx_ports(struct net_device *dev, bool push)
}
}
+static struct geneve_config *geneve_config_alloc(const struct geneve_config *src)
+{
+ struct geneve_config *cfg;
+ int err;
+
+ cfg = kmemdup(src, sizeof(*src), GFP_KERNEL);
+ if (!cfg)
+ return ERR_PTR(-ENOMEM);
+
+ cfg->info.dst_cache.cache = NULL;
+ err = dst_cache_init(&cfg->info.dst_cache, GFP_KERNEL);
+ if (err) {
+ kfree(cfg);
+ return ERR_PTR(err);
+ }
+
+ return cfg;
+}
+
+static void geneve_config_free(struct geneve_config *cfg)
+{
+ if (cfg) {
+ dst_cache_destroy(&cfg->info.dst_cache);
+ kfree(cfg);
+ }
+}
+
+static void geneve_config_free_rcu(struct rcu_head *head)
+{
+ struct geneve_config *cfg = container_of(head, struct geneve_config, rcu);
+
+ geneve_config_free(cfg);
+}
+
/* Initialize the device structure. */
+static void geneve_free_dev(struct net_device *dev)
+{
+ struct geneve_dev *geneve = netdev_priv(dev);
+ struct geneve_config *cfg = rcu_dereference_protected(geneve->cfg, 1);
+
+ geneve_config_free(cfg);
+}
+
static void geneve_setup(struct net_device *dev)
{
ether_setup(dev);
@@ -1717,6 +1790,8 @@ static void geneve_setup(struct net_device *dev)
dev->netdev_ops = &geneve_netdev_ops;
dev->ethtool_ops = &geneve_ethtool_ops;
dev->needs_free_netdev = true;
+ dev->priv_destructor = geneve_free_dev;
+
SET_NETDEV_DEVTYPE(dev, &geneve_type);
@@ -1878,15 +1953,17 @@ static struct geneve_dev *geneve_find_dev(struct geneve_net *gn,
*tun_on_same_port = false;
*tun_collect_md = false;
list_for_each_entry(geneve, &gn->geneve_list, next) {
- if (info->key.tp_dst == geneve->cfg.info.key.tp_dst &&
- (cfg->dualstack || geneve->cfg.dualstack ||
- geneve_saddr_conflict(info, &geneve->cfg.info))) {
- *tun_collect_md |= geneve->cfg.collect_md;
+ const struct geneve_config *gcfg = rtnl_dereference(geneve->cfg);
+
+ if (info->key.tp_dst == gcfg->info.key.tp_dst &&
+ (cfg->dualstack || gcfg->dualstack ||
+ geneve_saddr_conflict(info, &gcfg->info))) {
+ *tun_collect_md |= gcfg->collect_md;
*tun_on_same_port = true;
}
- if (info->key.tun_id == geneve->cfg.info.key.tun_id &&
- info->key.tp_dst == geneve->cfg.info.key.tp_dst &&
- !memcmp(&info->key.u, &geneve->cfg.info.key.u, sizeof(info->key.u)))
+ if (info->key.tun_id == gcfg->info.key.tun_id &&
+ info->key.tp_dst == gcfg->info.key.tp_dst &&
+ !memcmp(&info->key.u, &gcfg->info.key.u, sizeof(info->key.u)))
t = geneve;
}
return t;
@@ -1922,6 +1999,7 @@ static int geneve_configure(struct net *net, struct net_device *dev,
struct geneve_dev *t, *geneve = netdev_priv(dev);
const struct ip_tunnel_info *info = &cfg->info;
bool tun_collect_md, tun_on_same_port;
+ struct geneve_config *new_cfg;
int err, encap_len;
if (cfg->collect_md && !is_tnl_info_zero(info)) {
@@ -1962,10 +2040,13 @@ static int geneve_configure(struct net *net, struct net_device *dev,
}
}
- dst_cache_reset(&geneve->cfg.info.dst_cache);
- memcpy(&geneve->cfg, cfg, sizeof(*cfg));
+ new_cfg = geneve_config_alloc(cfg);
+ if (IS_ERR(new_cfg))
+ return PTR_ERR(new_cfg);
- if (geneve->cfg.inner_proto_inherit) {
+ rcu_assign_pointer(geneve->cfg, new_cfg);
+
+ if (cfg->inner_proto_inherit) {
dev->header_ops = NULL;
dev->type = ARPHRD_NONE;
dev->hard_header_len = 0;
@@ -1975,10 +2056,15 @@ static int geneve_configure(struct net *net, struct net_device *dev,
err = register_netdevice(dev);
if (err)
- return err;
+ goto err_free_cfg;
list_add(&geneve->next, &gn->geneve_list);
return 0;
+
+err_free_cfg:
+ geneve_config_free(new_cfg);
+ RCU_INIT_POINTER(geneve->cfg, NULL);
+ return err;
}
static void init_tnl_info(struct ip_tunnel_info *info, __u16 dst_port)
@@ -2323,81 +2409,47 @@ static int geneve_newlink(struct net_device *dev,
return 0;
}
-/* Quiesces the geneve device data path for both TX and RX.
- *
- * On transmit geneve checks for non-NULL geneve_sock before it proceeds.
- * So, if we set that socket to NULL under RCU and wait for synchronize_net()
- * to complete for the existing set of in-flight packets to be transmitted,
- * then we would have quiesced the transmit data path. All the future packets
- * will get dropped until we unquiesce the data path.
- *
- * On receive geneve dereference the geneve_sock stashed in the socket. So,
- * if we set that to NULL under RCU and wait for synchronize_net() to
- * complete, then we would have quiesced the receive data path.
+/* Update the device configuration under RTNL.
+ * We use RCU swap to update the configuration atomically, so the data path
+ * (both TX and RX) can continue running without interruption or packet loss.
*/
-static void geneve_quiesce(struct geneve_dev *geneve, struct geneve_sock **gs4,
- struct geneve_sock **gs6)
-{
- *gs4 = rtnl_dereference(geneve->sock4);
- rcu_assign_pointer(geneve->sock4, NULL);
- if (*gs4)
- rcu_assign_sk_user_data((*gs4)->sk, NULL);
-#if IS_ENABLED(CONFIG_IPV6)
- *gs6 = rtnl_dereference(geneve->sock6);
- rcu_assign_pointer(geneve->sock6, NULL);
- if (*gs6)
- rcu_assign_sk_user_data((*gs6)->sk, NULL);
-#else
- *gs6 = NULL;
-#endif
- synchronize_net();
-}
-/* Resumes the geneve device data path for both TX and RX. */
-static void geneve_unquiesce(struct geneve_dev *geneve, struct geneve_sock *gs4,
- struct geneve_sock __maybe_unused *gs6)
-{
- rcu_assign_pointer(geneve->sock4, gs4);
- if (gs4)
- rcu_assign_sk_user_data(gs4->sk, gs4);
-#if IS_ENABLED(CONFIG_IPV6)
- rcu_assign_pointer(geneve->sock6, gs6);
- if (gs6)
- rcu_assign_sk_user_data(gs6->sk, gs6);
-#endif
-}
static int geneve_changelink(struct net_device *dev, struct nlattr *tb[],
struct nlattr *data[],
struct netlink_ext_ack *extack)
{
struct geneve_dev *geneve = netdev_priv(dev);
- struct geneve_sock *gs4, *gs6;
- struct geneve_config cfg;
+ struct geneve_config *old_cfg = rtnl_dereference(geneve->cfg);
+ struct geneve_config *cfg;
int err;
/* If the geneve device is configured for metadata (or externally
* controlled, for example, OVS), then nothing can be changed.
*/
- if (geneve->cfg.collect_md)
+ if (old_cfg->collect_md)
return -EOPNOTSUPP;
/* Start with the existing info. */
- memcpy(&cfg, &geneve->cfg, sizeof(cfg));
- err = geneve_nl2info(tb, data, extack, &cfg, true);
+ cfg = geneve_config_alloc(old_cfg);
+ if (IS_ERR(cfg))
+ return PTR_ERR(cfg);
+
+ err = geneve_nl2info(tb, data, extack, cfg, true);
if (err)
- return err;
+ goto err_free_cfg;
- if (!geneve_dst_addr_equal(&geneve->cfg.info, &cfg.info)) {
- dst_cache_reset(&cfg.info.dst_cache);
- geneve_link_config(dev, &cfg.info, tb);
- }
+ if (!geneve_dst_addr_equal(&old_cfg->info, &cfg->info))
+ geneve_link_config(dev, &cfg->info, tb);
- geneve_quiesce(geneve, &gs4, &gs6);
- memcpy(&geneve->cfg, &cfg, sizeof(cfg));
- geneve_unquiesce(geneve, gs4, gs6);
+ rcu_assign_pointer(geneve->cfg, cfg);
+ call_rcu_hurry(&old_cfg->rcu, geneve_config_free_rcu);
return 0;
+
+err_free_cfg:
+ geneve_config_free(cfg);
+ return err;
}
static void geneve_dellink(struct net_device *dev, struct list_head *head)
@@ -2432,12 +2484,13 @@ static size_t geneve_get_size(const struct net_device *dev)
static int geneve_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct geneve_dev *geneve = netdev_priv(dev);
- struct ip_tunnel_info *info = &geneve->cfg.info;
- bool ttl_inherit = geneve->cfg.ttl_inherit;
- bool metadata = geneve->cfg.collect_md;
+ struct geneve_config *cfg = rtnl_dereference(geneve->cfg);
+ struct ip_tunnel_info *info = &cfg->info;
+ bool ttl_inherit = cfg->ttl_inherit;
+ bool metadata = cfg->collect_md;
struct ifla_geneve_port_range ports = {
- .low = htons(geneve->cfg.port_min),
- .high = htons(geneve->cfg.port_max),
+ .low = htons(cfg->port_min),
+ .high = htons(cfg->port_max),
};
__u8 tmp_vni[3];
__u32 vni;
@@ -2468,17 +2521,17 @@ static int geneve_fill_info(struct sk_buff *skb, const struct net_device *dev)
#endif
}
- if (!geneve->cfg.dualstack) {
+ if (!cfg->dualstack) {
if (ip_tunnel_info_af(info) == AF_INET) {
if ((info->key.u.ipv4.src ||
- geneve->cfg.collect_md) &&
+ metadata) &&
nla_put_in_addr(skb, IFLA_GENEVE_LOCAL,
info->key.u.ipv4.src))
goto nla_put_failure;
#if IS_ENABLED(CONFIG_IPV6)
} else {
if ((!ipv6_addr_any(&info->key.u.ipv6.src) ||
- geneve->cfg.collect_md) &&
+ metadata) &&
nla_put_in6_addr(skb, IFLA_GENEVE_LOCAL6,
&info->key.u.ipv6.src))
goto nla_put_failure;
@@ -2491,7 +2544,7 @@ static int geneve_fill_info(struct sk_buff *skb, const struct net_device *dev)
nla_put_be32(skb, IFLA_GENEVE_LABEL, info->key.label))
goto nla_put_failure;
- if (nla_put_u8(skb, IFLA_GENEVE_DF, geneve->cfg.df))
+ if (nla_put_u8(skb, IFLA_GENEVE_DF, cfg->df))
goto nla_put_failure;
if (nla_put_be16(skb, IFLA_GENEVE_PORT, info->key.tp_dst))
@@ -2502,21 +2555,21 @@ static int geneve_fill_info(struct sk_buff *skb, const struct net_device *dev)
#if IS_ENABLED(CONFIG_IPV6)
if (nla_put_u8(skb, IFLA_GENEVE_UDP_ZERO_CSUM6_RX,
- !geneve->cfg.use_udp6_rx_checksums))
+ !cfg->use_udp6_rx_checksums))
goto nla_put_failure;
#endif
if (nla_put_u8(skb, IFLA_GENEVE_TTL_INHERIT, ttl_inherit))
goto nla_put_failure;
- if (geneve->cfg.inner_proto_inherit &&
+ if (cfg->inner_proto_inherit &&
nla_put_flag(skb, IFLA_GENEVE_INNER_PROTO_INHERIT))
goto nla_put_failure;
if (nla_put(skb, IFLA_GENEVE_PORT_RANGE, sizeof(ports), &ports))
goto nla_put_failure;
- if (geneve->cfg.gro_hint &&
+ if (cfg->gro_hint &&
nla_put_flag(skb, IFLA_GENEVE_GRO_HINT))
goto nla_put_failure;
@@ -2671,6 +2724,7 @@ static void __exit geneve_cleanup_module(void)
rtnl_link_unregister(&geneve_link_ops);
unregister_netdevice_notifier(&geneve_notifier_block);
unregister_pernet_subsys(&geneve_net_ops);
+ rcu_barrier();
}
module_exit(geneve_cleanup_module);
--
2.55.0.rc0.799.gd6f94ed593-goog
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