From 5110effee8fde2edfacac9cd12a9960ab2dc39ea Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Mon, 2 Jul 2012 02:21:03 -0700 Subject: [PATCH] net: Do delayed neigh confirmation. When a dst_confirm() happens, mark the confirmation as pending in the dst. Then on the next packet out, when we have the neigh in-hand, do the update. This removes the dependency in dst_confirm() of dst's having an attached neigh. While we're here, remove the explicit 'dst' NULL check, all except 2 or 3 call sites ensure it's not NULL. So just fix those cases up. Signed-off-by: David S. Miller --- include/net/dst.h | 29 +++++++++++++++++++++-------- include/net/neighbour.h | 15 --------------- net/core/dst.c | 3 ++- net/ipv4/ip_output.c | 2 +- net/ipv4/tcp_input.c | 19 +++++++++++++------ net/ipv6/ip6_output.c | 2 +- 6 files changed, 38 insertions(+), 32 deletions(-) diff --git a/include/net/dst.h b/include/net/dst.h index f0bf3b8d5911..84e7a3ff968d 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -51,7 +51,7 @@ struct dst_entry { int (*input)(struct sk_buff *); int (*output)(struct sk_buff *); - int flags; + unsigned short flags; #define DST_HOST 0x0001 #define DST_NOXFRM 0x0002 #define DST_NOPOLICY 0x0004 @@ -62,6 +62,8 @@ struct dst_entry { #define DST_FAKE_RTABLE 0x0080 #define DST_XFRM_TUNNEL 0x0100 + unsigned short pending_confirm; + short error; short obsolete; unsigned short header_len; /* more space at head required */ @@ -371,7 +373,8 @@ static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb) extern int dst_discard(struct sk_buff *skb); extern void *dst_alloc(struct dst_ops *ops, struct net_device *dev, - int initial_ref, int initial_obsolete, int flags); + int initial_ref, int initial_obsolete, + unsigned short flags); extern void __dst_free(struct dst_entry *dst); extern struct dst_entry *dst_destroy(struct dst_entry *dst); @@ -395,14 +398,24 @@ static inline void dst_rcu_free(struct rcu_head *head) static inline void dst_confirm(struct dst_entry *dst) { - if (dst) { - struct neighbour *n; + dst->pending_confirm = 1; +} - rcu_read_lock(); - n = dst_get_neighbour_noref(dst); - neigh_confirm(n); - rcu_read_unlock(); +static inline int dst_neigh_output(struct dst_entry *dst, struct neighbour *n, + struct sk_buff *skb) +{ + struct hh_cache *hh; + + if (unlikely(dst->pending_confirm)) { + n->confirmed = jiffies; + dst->pending_confirm = 0; } + + hh = &n->hh; + if ((n->nud_state & NUD_CONNECTED) && hh->hh_len) + return neigh_hh_output(hh, skb); + else + return n->output(n, skb); } static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr) diff --git a/include/net/neighbour.h b/include/net/neighbour.h index e1d18bdeebb8..344d8988842a 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -309,12 +309,6 @@ static inline struct neighbour * neigh_clone(struct neighbour *neigh) #define neigh_hold(n) atomic_inc(&(n)->refcnt) -static inline void neigh_confirm(struct neighbour *neigh) -{ - if (neigh) - neigh->confirmed = jiffies; -} - static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) { unsigned long now = jiffies; @@ -358,15 +352,6 @@ static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb) return dev_queue_xmit(skb); } -static inline int neigh_output(struct neighbour *n, struct sk_buff *skb) -{ - struct hh_cache *hh = &n->hh; - if ((n->nud_state & NUD_CONNECTED) && hh->hh_len) - return neigh_hh_output(hh, skb); - else - return n->output(n, skb); -} - static inline struct neighbour * __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) { diff --git a/net/core/dst.c b/net/core/dst.c index 43d94cedbf7c..a6e19a23a745 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -152,7 +152,7 @@ EXPORT_SYMBOL(dst_discard); const u32 dst_default_metrics[RTAX_MAX]; void *dst_alloc(struct dst_ops *ops, struct net_device *dev, - int initial_ref, int initial_obsolete, int flags) + int initial_ref, int initial_obsolete, unsigned short flags) { struct dst_entry *dst; @@ -188,6 +188,7 @@ void *dst_alloc(struct dst_ops *ops, struct net_device *dev, dst->__use = 0; dst->lastuse = jiffies; dst->flags = flags; + dst->pending_confirm = 0; dst->next = NULL; if (!(flags & DST_NOCOUNT)) dst_entries_add(ops, 1); diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 6e9a266a0535..cc52679790b2 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -198,7 +198,7 @@ static inline int ip_finish_output2(struct sk_buff *skb) if (unlikely(!neigh)) neigh = __neigh_create(&arp_tbl, &nexthop, dev, false); if (neigh) { - int res = neigh_output(neigh, skb); + int res = dst_neigh_output(dst, neigh, skb); rcu_read_unlock_bh(); return res; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 8416f8a68e65..ca0d0e7c9778 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -740,13 +740,13 @@ void tcp_update_metrics(struct sock *sk) if (sysctl_tcp_nometrics_save) return; - dst_confirm(dst); - if (dst && (dst->flags & DST_HOST)) { const struct inet_connection_sock *icsk = inet_csk(sk); int m; unsigned long rtt; + dst_confirm(dst); + if (icsk->icsk_backoff || !tp->srtt) { /* This session failed to estimate rtt. Why? * Probably, no packets returned in time. @@ -3869,9 +3869,11 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) tcp_cong_avoid(sk, ack, prior_in_flight); } - if ((flag & FLAG_FORWARD_PROGRESS) || !(flag & FLAG_NOT_DUP)) - dst_confirm(__sk_dst_get(sk)); - + if ((flag & FLAG_FORWARD_PROGRESS) || !(flag & FLAG_NOT_DUP)) { + struct dst_entry *dst = __sk_dst_get(sk); + if (dst) + dst_confirm(dst); + } return 1; no_queue: @@ -6140,9 +6142,14 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb, case TCP_FIN_WAIT1: if (tp->snd_una == tp->write_seq) { + struct dst_entry *dst; + tcp_set_state(sk, TCP_FIN_WAIT2); sk->sk_shutdown |= SEND_SHUTDOWN; - dst_confirm(__sk_dst_get(sk)); + + dst = __sk_dst_get(sk); + if (dst) + dst_confirm(dst); if (!sock_flag(sk, SOCK_DEAD)) /* Wake up lingering close() */ diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index a233a7ccbc3a..c94e4aabe11b 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -125,7 +125,7 @@ static int ip6_finish_output2(struct sk_buff *skb) rcu_read_lock(); neigh = dst_get_neighbour_noref(dst); if (neigh) { - int res = neigh_output(neigh, skb); + int res = dst_neigh_output(dst, neigh, skb); rcu_read_unlock(); return res; -- 2.39.2