From 3e61aa8f0a68e6e007c223688f442be04a44b0f4 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Mon, 17 Jun 2013 14:16:12 -0700 Subject: [PATCH] vxlan: convert remotes list to list_rcu Based on initial work by Mike Rapoport Use list macros and RCU for tracking multiple remotes. Note: this code assumes list always has at least one entry, because delete is not supported. Signed-off-by: Stephen Hemminger --- drivers/net/vxlan.c | 97 +++++++++++++++++++++++++-------------------- 1 file changed, 55 insertions(+), 42 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index e65241c3d176..117b7fa6f33b 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -102,7 +102,7 @@ struct vxlan_rdst { __be16 remote_port; u32 remote_vni; u32 remote_ifindex; - struct vxlan_rdst *remote_next; + struct list_head list; }; /* Forwarding table entry */ @@ -111,7 +111,7 @@ struct vxlan_fdb { struct rcu_head rcu; unsigned long updated; /* jiffies */ unsigned long used; - struct vxlan_rdst remote; + struct list_head remotes; u16 state; /* see ndm_state */ u8 flags; /* see ndm_flags */ u8 eth_addr[ETH_ALEN]; @@ -170,6 +170,14 @@ static inline struct hlist_head *vs_head(struct net *net, __be16 port) return &vn->sock_list[hash_32(ntohs(port), PORT_HASH_BITS)]; } +/* First remote destination for a forwarding entry. + * Guaranteed to be non-NULL because remotes are never deleted. + */ +static inline struct vxlan_rdst *first_remote(struct vxlan_fdb *fdb) +{ + return list_first_or_null_rcu(&fdb->remotes, struct vxlan_rdst, list); +} + /* Find VXLAN socket based on network namespace and UDP port */ static struct vxlan_sock *vxlan_find_port(struct net *net, __be16 port) { @@ -275,7 +283,7 @@ static inline size_t vxlan_nlmsg_size(void) } static void vxlan_fdb_notify(struct vxlan_dev *vxlan, - const struct vxlan_fdb *fdb, int type) + struct vxlan_fdb *fdb, int type) { struct net *net = dev_net(vxlan->dev); struct sk_buff *skb; @@ -285,7 +293,7 @@ static void vxlan_fdb_notify(struct vxlan_dev *vxlan, if (skb == NULL) goto errout; - err = vxlan_fdb_info(skb, vxlan, fdb, 0, 0, type, 0, &fdb->remote); + err = vxlan_fdb_info(skb, vxlan, fdb, 0, 0, type, 0, first_remote(fdb)); if (err < 0) { /* -EMSGSIZE implies BUG in vxlan_nlmsg_size() */ WARN_ON(err == -EMSGSIZE); @@ -304,11 +312,16 @@ static void vxlan_ip_miss(struct net_device *dev, __be32 ipa) { struct vxlan_dev *vxlan = netdev_priv(dev); struct vxlan_fdb f; + struct vxlan_rdst remote; memset(&f, 0, sizeof f); f.state = NUD_STALE; - f.remote.remote_ip = ipa; /* goes to NDA_DST */ - f.remote.remote_vni = VXLAN_N_VID; + + remote.remote_ip = ipa; /* goes to NDA_DST */ + remote.remote_vni = VXLAN_N_VID; + + INIT_LIST_HEAD(&f.remotes); + list_add_rcu(&remote.list, &f.remotes); vxlan_fdb_notify(vxlan, &f, RTM_GETNEIGH); } @@ -318,6 +331,7 @@ static void vxlan_fdb_miss(struct vxlan_dev *vxlan, const u8 eth_addr[ETH_ALEN]) struct vxlan_fdb f; memset(&f, 0, sizeof f); + INIT_LIST_HEAD(&f.remotes); f.state = NUD_STALE; memcpy(f.eth_addr, eth_addr, ETH_ALEN); @@ -377,17 +391,17 @@ static struct vxlan_fdb *vxlan_find_mac(struct vxlan_dev *vxlan, static int vxlan_fdb_append(struct vxlan_fdb *f, __be32 ip, __be16 port, __u32 vni, __u32 ifindex) { - struct vxlan_rdst *rd_prev, *rd; + struct vxlan_rdst *rd; - rd_prev = NULL; - for (rd = &f->remote; rd; rd = rd->remote_next) { + /* protected by vxlan->hash_lock */ + list_for_each_entry(rd, &f->remotes, list) { if (rd->remote_ip == ip && rd->remote_port == port && rd->remote_vni == vni && rd->remote_ifindex == ifindex) return 0; - rd_prev = rd; } + rd = kmalloc(sizeof(*rd), GFP_ATOMIC); if (rd == NULL) return -ENOBUFS; @@ -395,8 +409,9 @@ static int vxlan_fdb_append(struct vxlan_fdb *f, rd->remote_port = port; rd->remote_vni = vni; rd->remote_ifindex = ifindex; - rd->remote_next = NULL; - rd_prev->remote_next = rd; + + list_add_tail_rcu(&rd->list, &f->remotes); + return 1; } @@ -448,16 +463,14 @@ static int vxlan_fdb_create(struct vxlan_dev *vxlan, return -ENOMEM; notify = 1; - f->remote.remote_ip = ip; - f->remote.remote_port = port; - f->remote.remote_vni = vni; - f->remote.remote_ifindex = ifindex; - f->remote.remote_next = NULL; f->state = state; f->flags = ndm_flags; f->updated = f->used = jiffies; + INIT_LIST_HEAD(&f->remotes); memcpy(f->eth_addr, mac, ETH_ALEN); + vxlan_fdb_append(f, ip, port, vni, ifindex); + ++vxlan->addrcnt; hlist_add_head_rcu(&f->hlist, vxlan_fdb_head(vxlan, mac)); @@ -472,13 +485,10 @@ static int vxlan_fdb_create(struct vxlan_dev *vxlan, static void vxlan_fdb_free(struct rcu_head *head) { struct vxlan_fdb *f = container_of(head, struct vxlan_fdb, rcu); + struct vxlan_rdst *rd, *nd; - while (f->remote.remote_next) { - struct vxlan_rdst *rd = f->remote.remote_next; - - f->remote.remote_next = rd->remote_next; + list_for_each_entry_safe(rd, nd, &f->remotes, list) kfree(rd); - } kfree(f); } @@ -588,23 +598,24 @@ static int vxlan_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb, hlist_for_each_entry_rcu(f, &vxlan->fdb_head[h], hlist) { struct vxlan_rdst *rd; - for (rd = &f->remote; rd; rd = rd->remote_next) { - if (idx < cb->args[0]) - goto skip; + if (idx < cb->args[0]) + goto skip; + + list_for_each_entry_rcu(rd, &f->remotes, list) { err = vxlan_fdb_info(skb, vxlan, f, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, RTM_NEWNEIGH, NLM_F_MULTI, rd); if (err < 0) - break; -skip: - ++idx; + goto out; } +skip: + ++idx; } } - +out: return idx; } @@ -620,7 +631,9 @@ static bool vxlan_snoop(struct net_device *dev, f = vxlan_find_mac(vxlan, src_mac); if (likely(f)) { - if (likely(f->remote.remote_ip == src_ip)) + struct vxlan_rdst *rdst = first_remote(f); + + if (likely(rdst->remote_ip == src_ip)) return false; /* Don't migrate static entries, drop packets */ @@ -630,9 +643,9 @@ static bool vxlan_snoop(struct net_device *dev, if (net_ratelimit()) netdev_info(dev, "%pM migrated from %pI4 to %pI4\n", - src_mac, &f->remote.remote_ip, &src_ip); + src_mac, &rdst->remote_ip, &src_ip); - f->remote.remote_ip = src_ip; + rdst->remote_ip = src_ip; f->updated = jiffies; vxlan_fdb_notify(vxlan, f, RTM_NEWNEIGH); } else { @@ -866,7 +879,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb) } f = vxlan_find_mac(vxlan, n->ha); - if (f && f->remote.remote_ip == htonl(INADDR_ANY)) { + if (f && first_remote(f)->remote_ip == htonl(INADDR_ANY)) { /* bridge-local neighbor */ neigh_release(n); goto out; @@ -1165,17 +1178,17 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev) (vxlan->flags & VXLAN_F_L2MISS) && !is_multicast_ether_addr(eth->h_dest)) vxlan_fdb_miss(vxlan, eth->h_dest); - } else - rdst0 = &f->remote; - + } else { + rdst = rdst0 = first_remote(f); - /* if there are multiple destinations, send copies */ - for (rdst = rdst0->remote_next; rdst; rdst = rdst->remote_next) { - struct sk_buff *skb1; + /* if there are multiple destinations, send copies */ + list_for_each_entry_continue_rcu(rdst, &f->remotes, list) { + struct sk_buff *skb1; - skb1 = skb_clone(skb, GFP_ATOMIC); - if (skb1) - vxlan_xmit_one(skb1, dev, rdst, did_rsc); + skb1 = skb_clone(skb, GFP_ATOMIC); + if (skb1) + vxlan_xmit_one(skb1, dev, rdst, did_rsc); + } } vxlan_xmit_one(skb, dev, rdst0, did_rsc); -- 2.34.1