From f3f05f7046e7c85b04af390d95a82a27160dd5d0 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Tue, 9 Aug 2005 20:08:09 -0700 Subject: [PATCH] [INET]: Generalise the tcp_listen_ lock routines Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- include/net/inet_hashtables.h | 48 +++++++++++++++++++++++++++++ include/net/tcp.h | 21 ------------- net/ipv4/inet_hashtables.c | 32 ++++++++++++++++++++ net/ipv4/tcp_diag.c | 8 ++--- net/ipv4/tcp_ipv4.c | 70 ++++++------------------------------------- net/ipv6/tcp_ipv6.c | 2 +- 6 files changed, 94 insertions(+), 87 deletions(-) diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h index da07411b36d..f5d65121f7b 100644 --- a/include/net/inet_hashtables.h +++ b/include/net/inet_hashtables.h @@ -19,10 +19,14 @@ #include #include #include +#include /* only for TCP_LISTEN, damn :-( */ #include +#include #include +#include + /* This is for all connections with a full identity, no wildcards. * New scheme, half the table is for TIME_WAIT, the other half is * for the rest. I'll experiment with dynamic table growth later. @@ -192,4 +196,48 @@ static inline void inet_inherit_port(struct inet_hashinfo *table, extern void inet_put_port(struct inet_hashinfo *table, struct sock *sk); +extern void inet_listen_wlock(struct inet_hashinfo *hashinfo); + +/* + * - We may sleep inside this lock. + * - If sleeping is not required (or called from BH), + * use plain read_(un)lock(&inet_hashinfo.lhash_lock). + */ +static inline void inet_listen_lock(struct inet_hashinfo *hashinfo) +{ + /* read_lock synchronizes to candidates to writers */ + read_lock(&hashinfo->lhash_lock); + atomic_inc(&hashinfo->lhash_users); + read_unlock(&hashinfo->lhash_lock); +} + +static inline void inet_listen_unlock(struct inet_hashinfo *hashinfo) +{ + if (atomic_dec_and_test(&hashinfo->lhash_users)) + wake_up(&hashinfo->lhash_wait); +} + +static inline void __inet_hash(struct inet_hashinfo *hashinfo, + struct sock *sk, const int listen_possible) +{ + struct hlist_head *list; + rwlock_t *lock; + + BUG_TRAP(sk_unhashed(sk)); + if (listen_possible && sk->sk_state == TCP_LISTEN) { + list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; + lock = &hashinfo->lhash_lock; + inet_listen_wlock(hashinfo); + } else { + sk->sk_hashent = inet_sk_ehashfn(sk, hashinfo->ehash_size); + list = &hashinfo->ehash[sk->sk_hashent].chain; + lock = &hashinfo->ehash[sk->sk_hashent].lock; + write_lock(lock); + } + __sk_add_node(sk, list); + sock_prot_inc_use(sk->sk_prot); + write_unlock(lock); + if (listen_possible && sk->sk_state == TCP_LISTEN) + wake_up(&hashinfo->lhash_wait); +} #endif /* _INET_HASHTABLES_H */ diff --git a/include/net/tcp.h b/include/net/tcp.h index 99e47695d4b..bc110cc7022 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1447,27 +1447,6 @@ static __inline__ void tcp_openreq_init(struct request_sock *req, extern void tcp_enter_memory_pressure(void); -extern void tcp_listen_wlock(void); - -/* - We may sleep inside this lock. - * - If sleeping is not required (or called from BH), - * use plain read_(un)lock(&inet_hashinfo.lhash_lock). - */ - -static inline void tcp_listen_lock(void) -{ - /* read_lock synchronizes to candidates to writers */ - read_lock(&tcp_hashinfo.lhash_lock); - atomic_inc(&tcp_hashinfo.lhash_users); - read_unlock(&tcp_hashinfo.lhash_lock); -} - -static inline void tcp_listen_unlock(void) -{ - if (atomic_dec_and_test(&tcp_hashinfo.lhash_users)) - wake_up(&tcp_hashinfo.lhash_wait); -} - static inline int keepalive_intvl_when(const struct tcp_sock *tp) { return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl; diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index 33d6cbe32cd..06cbc6f689c 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -15,7 +15,9 @@ #include #include +#include #include +#include #include @@ -89,3 +91,33 @@ void inet_put_port(struct inet_hashinfo *hashinfo, struct sock *sk) } EXPORT_SYMBOL(inet_put_port); + +/* + * This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP. + * Look, when several writers sleep and reader wakes them up, all but one + * immediately hit write lock and grab all the cpus. Exclusive sleep solves + * this, _but_ remember, it adds useless work on UP machines (wake up each + * exclusive lock release). It should be ifdefed really. + */ +void inet_listen_wlock(struct inet_hashinfo *hashinfo) +{ + write_lock(&hashinfo->lhash_lock); + + if (atomic_read(&hashinfo->lhash_users)) { + DEFINE_WAIT(wait); + + for (;;) { + prepare_to_wait_exclusive(&hashinfo->lhash_wait, + &wait, TASK_UNINTERRUPTIBLE); + if (!atomic_read(&hashinfo->lhash_users)) + break; + write_unlock_bh(&hashinfo->lhash_lock); + schedule(); + write_lock_bh(&hashinfo->lhash_lock); + } + + finish_wait(&hashinfo->lhash_wait, &wait); + } +} + +EXPORT_SYMBOL(inet_listen_wlock); diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c index 0ae738b455f..1a89a03c449 100644 --- a/net/ipv4/tcp_diag.c +++ b/net/ipv4/tcp_diag.c @@ -589,7 +589,7 @@ static int tcpdiag_dump(struct sk_buff *skb, struct netlink_callback *cb) if (cb->args[0] == 0) { if (!(r->tcpdiag_states&(TCPF_LISTEN|TCPF_SYN_RECV))) goto skip_listen_ht; - tcp_listen_lock(); + inet_listen_lock(&tcp_hashinfo); for (i = s_i; i < INET_LHTABLE_SIZE; i++) { struct sock *sk; struct hlist_node *node; @@ -613,7 +613,7 @@ static int tcpdiag_dump(struct sk_buff *skb, struct netlink_callback *cb) goto syn_recv; if (tcpdiag_dump_sock(skb, sk, cb) < 0) { - tcp_listen_unlock(); + inet_listen_unlock(&tcp_hashinfo); goto done; } @@ -622,7 +622,7 @@ syn_recv: goto next_listen; if (tcpdiag_dump_reqs(skb, sk, cb) < 0) { - tcp_listen_unlock(); + inet_listen_unlock(&tcp_hashinfo); goto done; } @@ -636,7 +636,7 @@ next_listen: cb->args[3] = 0; cb->args[4] = 0; } - tcp_listen_unlock(); + inet_listen_unlock(&tcp_hashinfo); skip_listen_ht: cb->args[0] = 1; s_i = num = s_num = 0; diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index f5373f9f00a..5f9ad95304c 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -228,62 +228,11 @@ fail: return ret; } -/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP. - * Look, when several writers sleep and reader wakes them up, all but one - * immediately hit write lock and grab all the cpus. Exclusive sleep solves - * this, _but_ remember, it adds useless work on UP machines (wake up each - * exclusive lock release). It should be ifdefed really. - */ - -void tcp_listen_wlock(void) -{ - write_lock(&tcp_hashinfo.lhash_lock); - - if (atomic_read(&tcp_hashinfo.lhash_users)) { - DEFINE_WAIT(wait); - - for (;;) { - prepare_to_wait_exclusive(&tcp_hashinfo.lhash_wait, - &wait, TASK_UNINTERRUPTIBLE); - if (!atomic_read(&tcp_hashinfo.lhash_users)) - break; - write_unlock_bh(&tcp_hashinfo.lhash_lock); - schedule(); - write_lock_bh(&tcp_hashinfo.lhash_lock); - } - - finish_wait(&tcp_hashinfo.lhash_wait, &wait); - } -} - -static __inline__ void __tcp_v4_hash(struct sock *sk, const int listen_possible) -{ - struct hlist_head *list; - rwlock_t *lock; - - BUG_TRAP(sk_unhashed(sk)); - if (listen_possible && sk->sk_state == TCP_LISTEN) { - list = &tcp_hashinfo.listening_hash[inet_sk_listen_hashfn(sk)]; - lock = &tcp_hashinfo.lhash_lock; - tcp_listen_wlock(); - } else { - sk->sk_hashent = inet_sk_ehashfn(sk, tcp_hashinfo.ehash_size); - list = &tcp_hashinfo.ehash[sk->sk_hashent].chain; - lock = &tcp_hashinfo.ehash[sk->sk_hashent].lock; - write_lock(lock); - } - __sk_add_node(sk, list); - sock_prot_inc_use(sk->sk_prot); - write_unlock(lock); - if (listen_possible && sk->sk_state == TCP_LISTEN) - wake_up(&tcp_hashinfo.lhash_wait); -} - static void tcp_v4_hash(struct sock *sk) { if (sk->sk_state != TCP_CLOSE) { local_bh_disable(); - __tcp_v4_hash(sk, 1); + __inet_hash(&tcp_hashinfo, sk, 1); local_bh_enable(); } } @@ -297,7 +246,7 @@ void tcp_unhash(struct sock *sk) if (sk->sk_state == TCP_LISTEN) { local_bh_disable(); - tcp_listen_wlock(); + inet_listen_wlock(&tcp_hashinfo); lock = &tcp_hashinfo.lhash_lock; } else { struct inet_ehash_bucket *head = &tcp_hashinfo.ehash[sk->sk_hashent]; @@ -624,7 +573,7 @@ ok: inet_bind_hash(sk, tb, port); if (sk_unhashed(sk)) { inet_sk(sk)->sport = htons(port); - __tcp_v4_hash(sk, 0); + __inet_hash(&tcp_hashinfo, sk, 0); } spin_unlock(&head->lock); @@ -641,7 +590,7 @@ ok: tb = inet_sk(sk)->bind_hash; spin_lock_bh(&head->lock); if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) { - __tcp_v4_hash(sk, 0); + __inet_hash(&tcp_hashinfo, sk, 0); spin_unlock_bh(&head->lock); return 0; } else { @@ -1479,7 +1428,7 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, newtp->advmss = dst_metric(dst, RTAX_ADVMSS); tcp_initialize_rcv_mss(newsk); - __tcp_v4_hash(newsk, 0); + __inet_hash(&tcp_hashinfo, newsk, 0); __inet_inherit_port(&tcp_hashinfo, sk, newsk); return newsk; @@ -2102,12 +2051,12 @@ static void *tcp_get_idx(struct seq_file *seq, loff_t pos) void *rc; struct tcp_iter_state* st = seq->private; - tcp_listen_lock(); + inet_listen_lock(&tcp_hashinfo); st->state = TCP_SEQ_STATE_LISTENING; rc = listening_get_idx(seq, &pos); if (!rc) { - tcp_listen_unlock(); + inet_listen_unlock(&tcp_hashinfo); local_bh_disable(); st->state = TCP_SEQ_STATE_ESTABLISHED; rc = established_get_idx(seq, pos); @@ -2140,7 +2089,7 @@ static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) case TCP_SEQ_STATE_LISTENING: rc = listening_get_next(seq, v); if (!rc) { - tcp_listen_unlock(); + inet_listen_unlock(&tcp_hashinfo); local_bh_disable(); st->state = TCP_SEQ_STATE_ESTABLISHED; rc = established_get_first(seq); @@ -2168,7 +2117,7 @@ static void tcp_seq_stop(struct seq_file *seq, void *v) } case TCP_SEQ_STATE_LISTENING: if (v != SEQ_START_TOKEN) - tcp_listen_unlock(); + inet_listen_unlock(&tcp_hashinfo); break; case TCP_SEQ_STATE_TIME_WAIT: case TCP_SEQ_STATE_ESTABLISHED: @@ -2431,7 +2380,6 @@ void __init tcp_v4_init(struct net_proto_family *ops) EXPORT_SYMBOL(ipv4_specific); EXPORT_SYMBOL(inet_bind_bucket_create); EXPORT_SYMBOL(tcp_hashinfo); -EXPORT_SYMBOL(tcp_listen_wlock); EXPORT_SYMBOL(tcp_prot); EXPORT_SYMBOL(tcp_unhash); EXPORT_SYMBOL(tcp_v4_conn_request); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 362ef5a6406..93a66b9a76e 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -229,7 +229,7 @@ static __inline__ void __tcp_v6_hash(struct sock *sk) if (sk->sk_state == TCP_LISTEN) { list = &tcp_hashinfo.listening_hash[inet_sk_listen_hashfn(sk)]; lock = &tcp_hashinfo.lhash_lock; - tcp_listen_wlock(); + inet_listen_wlock(&tcp_hashinfo); } else { sk->sk_hashent = tcp_v6_sk_hashfn(sk); list = &tcp_hashinfo.ehash[sk->sk_hashent].chain; -- 2.11.4.GIT