5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Martin KaFai Lau kafai@fb.com
[ Upstream commit cae3873c5b3a4fcd9706fb461ff4e91bdf1f0120 ]
The listen sk is currently stored in two hash tables, listening_hash (hashed by port) and lhash2 (hashed by port and address).
After commit 0ee58dad5b06 ("net: tcp6: prefer listeners bound to an address") and commit d9fbc7f6431f ("net: tcp: prefer listeners bound to an address"), the TCP-SYN lookup fast path does not use listening_hash.
The commit 05c0b35709c5 ("tcp: seq_file: Replace listening_hash with lhash2") also moved the seq_file (/proc/net/tcp) iteration usage from listening_hash to lhash2.
There are still a few listening_hash usages left. One of them is inet_reuseport_add_sock() which uses the listening_hash to search a listen sk during the listen() system call. This turns out to be very slow on use cases that listen on many different VIPs at a popular port (e.g. 443). [ On top of the slowness in adding to the tail in the IPv6 case ]. The latter patch has a selftest to demonstrate this case.
This patch takes this chance to move all remaining listening_hash usages to lhash2 and then retire listening_hash.
Since most changes need to be done together, it is hard to cut the listening_hash to lhash2 switch into small patches. The changes in this patch is highlighted here for the review purpose.
1. Because of the listening_hash removal, lhash2 can use the sk->sk_nulls_node instead of the icsk->icsk_listen_portaddr_node. This will also keep the sk_unhashed() check to work as is after stop adding sk to listening_hash.
The union is removed from inet_listen_hashbucket because only nulls_head is needed.
2. icsk->icsk_listen_portaddr_node and its helpers are removed.
3. The current lhash2 users needs to iterate with sk_nulls_node instead of icsk_listen_portaddr_node.
One case is in the inet[6]_lhash2_lookup().
Another case is the seq_file iterator in tcp_ipv4.c. One thing to note is sk_nulls_next() is needed because the old inet_lhash2_for_each_icsk_continue() does a "next" first before iterating.
4. Move the remaining listening_hash usage to lhash2
inet_reuseport_add_sock() which this series is trying to improve.
inet_diag.c and mptcp_diag.c are the final two remaining use cases and is moved to lhash2 now also.
Signed-off-by: Martin KaFai Lau kafai@fb.com Reviewed-by: Eric Dumazet edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: 871019b22d1b ("net: set SOCK_RCU_FREE before inserting socket into hashtable") Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/inet_connection_sock.h | 2 -- include/net/inet_hashtables.h | 41 +------------------------- net/dccp/proto.c | 1 - net/ipv4/inet_diag.c | 5 ++-- net/ipv4/inet_hashtables.c | 47 ++++++------------------------ net/ipv4/tcp.c | 1 - net/ipv4/tcp_ipv4.c | 21 ++++++------- net/ipv6/inet6_hashtables.c | 5 ++-- net/mptcp/mptcp_diag.c | 4 +-- 9 files changed, 26 insertions(+), 101 deletions(-)
diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index 695ed45841f06..d31a18824cd5c 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -66,7 +66,6 @@ struct inet_connection_sock_af_ops { * @icsk_ulp_ops Pluggable ULP control hook * @icsk_ulp_data ULP private data * @icsk_clean_acked Clean acked data hook - * @icsk_listen_portaddr_node hash to the portaddr listener hashtable * @icsk_ca_state: Congestion control state * @icsk_retransmits: Number of unrecovered [RTO] timeouts * @icsk_pending: Scheduled timer event @@ -96,7 +95,6 @@ struct inet_connection_sock { const struct tcp_ulp_ops *icsk_ulp_ops; void __rcu *icsk_ulp_data; void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); - struct hlist_node icsk_listen_portaddr_node; unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); __u8 icsk_ca_state:5, icsk_ca_initialized:1, diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h index 405670d7661da..a7a8e66a1bad0 100644 --- a/include/net/inet_hashtables.h +++ b/include/net/inet_hashtables.h @@ -111,10 +111,7 @@ struct inet_bind_hashbucket { #define LISTENING_NULLS_BASE (1U << 29) struct inet_listen_hashbucket { spinlock_t lock; - union { - struct hlist_head head; - struct hlist_nulls_head nulls_head; - }; + struct hlist_nulls_head nulls_head; };
/* This is for listening sockets, thus all sockets which possess wildcards. */ @@ -142,32 +139,8 @@ struct inet_hashinfo { /* The 2nd listener table hashed by local port and address */ unsigned int lhash2_mask; struct inet_listen_hashbucket *lhash2; - - /* All the above members are written once at bootup and - * never written again _or_ are predominantly read-access. - * - * Now align to a new cache line as all the following members - * might be often dirty. - */ - /* All sockets in TCP_LISTEN state will be in listening_hash. - * This is the only table where wildcard'd TCP sockets can - * exist. listening_hash is only hashed by local port number. - * If lhash2 is initialized, the same socket will also be hashed - * to lhash2 by port and address. - */ - struct inet_listen_hashbucket listening_hash[INET_LHTABLE_SIZE] - ____cacheline_aligned_in_smp; };
-#define inet_lhash2_for_each_icsk_continue(__icsk) \ - hlist_for_each_entry_continue(__icsk, icsk_listen_portaddr_node) - -#define inet_lhash2_for_each_icsk(__icsk, list) \ - hlist_for_each_entry(__icsk, list, icsk_listen_portaddr_node) - -#define inet_lhash2_for_each_icsk_rcu(__icsk, list) \ - hlist_for_each_entry_rcu(__icsk, list, icsk_listen_portaddr_node) - static inline struct inet_listen_hashbucket * inet_lhash2_bucket(struct inet_hashinfo *h, u32 hash) { @@ -218,23 +191,11 @@ static inline u32 inet_bhashfn(const struct net *net, const __u16 lport, void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb, const unsigned short snum);
-/* These can have wildcards, don't try too hard. */ -static inline u32 inet_lhashfn(const struct net *net, const unsigned short num) -{ - return (num + net_hash_mix(net)) & (INET_LHTABLE_SIZE - 1); -} - -static inline int inet_sk_listen_hashfn(const struct sock *sk) -{ - return inet_lhashfn(sock_net(sk), inet_sk(sk)->inet_num); -} - /* Caller must disable local BH processing. */ int __inet_inherit_port(const struct sock *sk, struct sock *child);
void inet_put_port(struct sock *sk);
-void inet_hashinfo_init(struct inet_hashinfo *h); void inet_hashinfo2_init(struct inet_hashinfo *h, const char *name, unsigned long numentries, int scale, unsigned long low_limit, diff --git a/net/dccp/proto.c b/net/dccp/proto.c index 0b0567a692a8f..1b285a57c7aab 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -1131,7 +1131,6 @@ static int __init dccp_init(void)
BUILD_BUG_ON(sizeof(struct dccp_skb_cb) > sizeof_field(struct sk_buff, cb)); - inet_hashinfo_init(&dccp_hashinfo); rc = inet_hashinfo2_init_mod(&dccp_hashinfo); if (rc) goto out_fail; diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index ae70e07c52445..09cabed358fd0 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -1028,12 +1028,13 @@ void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb, if (!(idiag_states & TCPF_LISTEN) || r->id.idiag_dport) goto skip_listen_ht;
- for (i = s_i; i < INET_LHTABLE_SIZE; i++) { + for (i = s_i; i <= hashinfo->lhash2_mask; i++) { struct inet_listen_hashbucket *ilb; struct hlist_nulls_node *node;
num = 0; - ilb = &hashinfo->listening_hash[i]; + ilb = &hashinfo->lhash2[i]; + spin_lock(&ilb->lock); sk_nulls_for_each(sk, node, &ilb->nulls_head) { struct inet_sock *inet = inet_sk(sk); diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index 637d806090b00..a673f4ec1b429 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -246,12 +246,11 @@ static struct sock *inet_lhash2_lookup(struct net *net, const __be32 daddr, const unsigned short hnum, const int dif, const int sdif) { - struct inet_connection_sock *icsk; struct sock *sk, *result = NULL; + struct hlist_nulls_node *node; int score, hiscore = 0;
- inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) { - sk = (struct sock *)icsk; + sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) { score = compute_score(sk, net, hnum, daddr, dif, sdif); if (score > hiscore) { result = lookup_reuseport(net, sk, skb, doff, @@ -593,7 +592,6 @@ int __inet_hash(struct sock *sk, struct sock *osk) { struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; struct inet_listen_hashbucket *ilb2; - struct inet_listen_hashbucket *ilb; int err = 0;
if (sk->sk_state != TCP_LISTEN) { @@ -603,31 +601,23 @@ int __inet_hash(struct sock *sk, struct sock *osk) return 0; } WARN_ON(!sk_unhashed(sk)); - ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; ilb2 = inet_lhash2_bucket_sk(hashinfo, sk);
- spin_lock(&ilb->lock); spin_lock(&ilb2->lock); if (sk->sk_reuseport) { - err = inet_reuseport_add_sock(sk, ilb); + err = inet_reuseport_add_sock(sk, ilb2); if (err) goto unlock; } if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && - sk->sk_family == AF_INET6) { - hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node, - &ilb2->head); - __sk_nulls_add_node_tail_rcu(sk, &ilb->nulls_head); - } else { - hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node, - &ilb2->head); - __sk_nulls_add_node_rcu(sk, &ilb->nulls_head); - } + sk->sk_family == AF_INET6) + __sk_nulls_add_node_tail_rcu(sk, &ilb2->nulls_head); + else + __sk_nulls_add_node_rcu(sk, &ilb2->nulls_head); sock_set_flag(sk, SOCK_RCU_FREE); sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); unlock: spin_unlock(&ilb2->lock); - spin_unlock(&ilb->lock);
return err; } @@ -653,29 +643,23 @@ void inet_unhash(struct sock *sk)
if (sk->sk_state == TCP_LISTEN) { struct inet_listen_hashbucket *ilb2; - struct inet_listen_hashbucket *ilb;
- ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; ilb2 = inet_lhash2_bucket_sk(hashinfo, sk); /* Don't disable bottom halves while acquiring the lock to * avoid circular locking dependency on PREEMPT_RT. */ - spin_lock(&ilb->lock); spin_lock(&ilb2->lock); if (sk_unhashed(sk)) { spin_unlock(&ilb2->lock); - spin_unlock(&ilb->lock); return; }
if (rcu_access_pointer(sk->sk_reuseport_cb)) reuseport_stop_listen_sock(sk);
- hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node); __sk_nulls_del_node_init_rcu(sk); sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); spin_unlock(&ilb2->lock); - spin_unlock(&ilb->lock); } else { spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
@@ -833,27 +817,14 @@ int inet_hash_connect(struct inet_timewait_death_row *death_row, } EXPORT_SYMBOL_GPL(inet_hash_connect);
-void inet_hashinfo_init(struct inet_hashinfo *h) -{ - int i; - - for (i = 0; i < INET_LHTABLE_SIZE; i++) { - spin_lock_init(&h->listening_hash[i].lock); - INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].nulls_head, - i + LISTENING_NULLS_BASE); - } - - h->lhash2 = NULL; -} -EXPORT_SYMBOL_GPL(inet_hashinfo_init); - static void init_hashinfo_lhash2(struct inet_hashinfo *h) { int i;
for (i = 0; i <= h->lhash2_mask; i++) { spin_lock_init(&h->lhash2[i].lock); - INIT_HLIST_HEAD(&h->lhash2[i].head); + INIT_HLIST_NULLS_HEAD(&h->lhash2[i].nulls_head, + i + LISTENING_NULLS_BASE); } }
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 6dcb77a2bde60..86dff7abdfd69 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4554,7 +4554,6 @@ void __init tcp_init(void) timer_setup(&tcp_orphan_timer, tcp_orphan_update, TIMER_DEFERRABLE); mod_timer(&tcp_orphan_timer, jiffies + TCP_ORPHAN_TIMER_PERIOD);
- inet_hashinfo_init(&tcp_hashinfo); inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash", thash_entries, 21, /* one slot per 2 MB*/ 0, 64 * 1024); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index f89cb184649ec..0666be6b9ec93 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2343,16 +2343,15 @@ static void *listening_get_first(struct seq_file *seq) st->offset = 0; for (; st->bucket <= tcp_hashinfo.lhash2_mask; st->bucket++) { struct inet_listen_hashbucket *ilb2; - struct inet_connection_sock *icsk; + struct hlist_nulls_node *node; struct sock *sk;
ilb2 = &tcp_hashinfo.lhash2[st->bucket]; - if (hlist_empty(&ilb2->head)) + if (hlist_nulls_empty(&ilb2->nulls_head)) continue;
spin_lock(&ilb2->lock); - inet_lhash2_for_each_icsk(icsk, &ilb2->head) { - sk = (struct sock *)icsk; + sk_nulls_for_each(sk, node, &ilb2->nulls_head) { if (seq_sk_match(seq, sk)) return sk; } @@ -2371,15 +2370,14 @@ static void *listening_get_next(struct seq_file *seq, void *cur) { struct tcp_iter_state *st = seq->private; struct inet_listen_hashbucket *ilb2; - struct inet_connection_sock *icsk; + struct hlist_nulls_node *node; struct sock *sk = cur;
++st->num; ++st->offset;
- icsk = inet_csk(sk); - inet_lhash2_for_each_icsk_continue(icsk) { - sk = (struct sock *)icsk; + sk = sk_nulls_next(sk); + sk_nulls_for_each_from(sk, node) { if (seq_sk_match(seq, sk)) return sk; } @@ -2788,16 +2786,15 @@ static unsigned int bpf_iter_tcp_listening_batch(struct seq_file *seq, { struct bpf_tcp_iter_state *iter = seq->private; struct tcp_iter_state *st = &iter->state; - struct inet_connection_sock *icsk; + struct hlist_nulls_node *node; unsigned int expected = 1; struct sock *sk;
sock_hold(start_sk); iter->batch[iter->end_sk++] = start_sk;
- icsk = inet_csk(start_sk); - inet_lhash2_for_each_icsk_continue(icsk) { - sk = (struct sock *)icsk; + sk = sk_nulls_next(start_sk); + sk_nulls_for_each_from(sk, node) { if (seq_sk_match(seq, sk)) { if (iter->end_sk < iter->max_sk) { sock_hold(sk); diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c index b4a5e01e12016..c40cbdfc6247f 100644 --- a/net/ipv6/inet6_hashtables.c +++ b/net/ipv6/inet6_hashtables.c @@ -138,12 +138,11 @@ static struct sock *inet6_lhash2_lookup(struct net *net, const __be16 sport, const struct in6_addr *daddr, const unsigned short hnum, const int dif, const int sdif) { - struct inet_connection_sock *icsk; struct sock *sk, *result = NULL; + struct hlist_nulls_node *node; int score, hiscore = 0;
- inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) { - sk = (struct sock *)icsk; + sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) { score = compute_score(sk, net, hnum, daddr, dif, sdif); if (score > hiscore) { result = lookup_reuseport(net, sk, skb, doff, diff --git a/net/mptcp/mptcp_diag.c b/net/mptcp/mptcp_diag.c index 4d8625d0b179a..520ee65850553 100644 --- a/net/mptcp/mptcp_diag.c +++ b/net/mptcp/mptcp_diag.c @@ -83,13 +83,13 @@ static void mptcp_diag_dump_listeners(struct sk_buff *skb, struct netlink_callba struct net *net = sock_net(skb->sk); int i;
- for (i = diag_ctx->l_slot; i < INET_LHTABLE_SIZE; i++) { + for (i = diag_ctx->l_slot; i <= tcp_hashinfo.lhash2_mask; i++) { struct inet_listen_hashbucket *ilb; struct hlist_nulls_node *node; struct sock *sk; int num = 0;
- ilb = &tcp_hashinfo.listening_hash[i]; + ilb = &tcp_hashinfo.lhash2[i];
rcu_read_lock(); spin_lock(&ilb->lock);