From 10cbc8f179177c1a6d5f56a46ebddc8f602ce5ac Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 2 Oct 2015 11:43:36 -0700 Subject: [PATCH] tcp/dccp: remove struct listen_sock It is enough to check listener sk_state, no need for an extra condition. max_qlen_log can be moved into struct request_sock_queue We can remove syn_wait_lock and the alignment it enforced. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/request_sock.h | 26 +++--------------- net/core/request_sock.c | 47 +++------------------------------ net/ipv4/inet_connection_sock.c | 14 +++------- 3 files changed, 11 insertions(+), 76 deletions(-) diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 353cb61bb399..a66ab1345373 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -119,14 +119,6 @@ static inline void reqsk_put(struct request_sock *req) extern int sysctl_max_syn_backlog; -/** struct listen_sock - listen state - * - * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs - */ -struct listen_sock { - u32 max_qlen_log; -}; - /* * For a TCP Fast Open listener - * lock - protects the access to all the reqsk, which is co-owned by @@ -160,36 +152,26 @@ struct fastopen_queue { * @rskq_accept_head - FIFO head of established children * @rskq_accept_tail - FIFO tail of established children * @rskq_defer_accept - User waits for some data after accept() - * @syn_wait_lock - serializer - * - * %syn_wait_lock is necessary only to avoid proc interface having to grab the main - * lock sock while browsing the listening hash (otherwise it's deadlock prone). * */ struct request_sock_queue { spinlock_t rskq_lock; u8 rskq_defer_accept; + u8 max_qlen_log; u32 synflood_warned; - atomic_t qlen; atomic_t young; struct request_sock *rskq_accept_head; struct request_sock *rskq_accept_tail; - struct listen_sock *listen_opt; struct fastopen_queue fastopenq; /* Check max_qlen != 0 to determine * if TFO is enabled. */ - - /* temporary alignment, our goal is to get rid of this lock */ - spinlock_t syn_wait_lock ____cacheline_aligned_in_smp; }; -int reqsk_queue_alloc(struct request_sock_queue *queue, - unsigned int nr_table_entries); +void reqsk_queue_alloc(struct request_sock_queue *queue, + unsigned int nr_table_entries); -void __reqsk_queue_destroy(struct request_sock_queue *queue); -void reqsk_queue_destroy(struct request_sock_queue *queue); void reqsk_fastopen_remove(struct sock *sk, struct request_sock *req, bool reset); @@ -260,7 +242,7 @@ static inline int reqsk_queue_len_young(const struct request_sock_queue *queue) static inline int reqsk_queue_is_full(const struct request_sock_queue *queue) { - return reqsk_queue_len(queue) >> queue->listen_opt->max_qlen_log; + return reqsk_queue_len(queue) >> queue->max_qlen_log; } #endif /* _REQUEST_SOCK_H */ diff --git a/net/core/request_sock.c b/net/core/request_sock.c index 124f61c5bfef..ecf74189bd3f 100644 --- a/net/core/request_sock.c +++ b/net/core/request_sock.c @@ -37,22 +37,14 @@ int sysctl_max_syn_backlog = 256; EXPORT_SYMBOL(sysctl_max_syn_backlog); -int reqsk_queue_alloc(struct request_sock_queue *queue, - unsigned int nr_table_entries) +void reqsk_queue_alloc(struct request_sock_queue *queue, + unsigned int nr_table_entries) { - size_t lopt_size = sizeof(struct listen_sock); - struct listen_sock *lopt = NULL; - nr_table_entries = min_t(u32, nr_table_entries, sysctl_max_syn_backlog); nr_table_entries = max_t(u32, nr_table_entries, 8); nr_table_entries = roundup_pow_of_two(nr_table_entries + 1); - lopt = kzalloc(lopt_size, GFP_KERNEL); - if (!lopt) - return -ENOMEM; - spin_lock_init(&queue->rskq_lock); - spin_lock_init(&queue->syn_wait_lock); spin_lock_init(&queue->fastopenq.lock); queue->fastopenq.rskq_rst_head = NULL; @@ -61,40 +53,7 @@ int reqsk_queue_alloc(struct request_sock_queue *queue, queue->fastopenq.max_qlen = 0; queue->rskq_accept_head = NULL; - lopt->max_qlen_log = ilog2(nr_table_entries); - - spin_lock_bh(&queue->syn_wait_lock); - queue->listen_opt = lopt; - spin_unlock_bh(&queue->syn_wait_lock); - - return 0; -} - -void __reqsk_queue_destroy(struct request_sock_queue *queue) -{ - /* This is an error recovery path only, no locking needed */ - kfree(queue->listen_opt); -} - -static inline struct listen_sock *reqsk_queue_yank_listen_sk( - struct request_sock_queue *queue) -{ - struct listen_sock *lopt; - - spin_lock_bh(&queue->syn_wait_lock); - lopt = queue->listen_opt; - queue->listen_opt = NULL; - spin_unlock_bh(&queue->syn_wait_lock); - - return lopt; -} - -void reqsk_queue_destroy(struct request_sock_queue *queue) -{ - struct listen_sock *lopt = reqsk_queue_yank_listen_sk(queue); - - /* cleaning is done by req timers */ - kfree(lopt); + queue->max_qlen_log = ilog2(nr_table_entries); } /* diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 099e0ea9242a..775483283fa7 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -552,12 +552,11 @@ static void reqsk_timer_handler(unsigned long data) struct sock *sk_listener = req->rsk_listener; struct inet_connection_sock *icsk = inet_csk(sk_listener); struct request_sock_queue *queue = &icsk->icsk_accept_queue; - struct listen_sock *lopt = queue->listen_opt; int qlen, expire = 0, resend = 0; int max_retries, thresh; u8 defer_accept; - if (sk_listener->sk_state != TCP_LISTEN || !lopt) + if (sk_listener->sk_state != TCP_LISTEN) goto drop; max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries; @@ -580,7 +579,7 @@ static void reqsk_timer_handler(unsigned long data) * ones are about to clog our table. */ qlen = reqsk_queue_len(queue); - if (qlen >> (lopt->max_qlen_log - 1)) { + if (qlen >> (queue->max_qlen_log - 1)) { int young = reqsk_queue_len_young(queue) << 1; while (thresh > 2) { @@ -730,12 +729,10 @@ EXPORT_SYMBOL(inet_csk_prepare_forced_close); int inet_csk_listen_start(struct sock *sk, const int nr_table_entries) { - struct inet_sock *inet = inet_sk(sk); struct inet_connection_sock *icsk = inet_csk(sk); - int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries); + struct inet_sock *inet = inet_sk(sk); - if (rc != 0) - return rc; + reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries); sk->sk_max_ack_backlog = 0; sk->sk_ack_backlog = 0; @@ -757,7 +754,6 @@ int inet_csk_listen_start(struct sock *sk, const int nr_table_entries) } sk->sk_state = TCP_CLOSE; - __reqsk_queue_destroy(&icsk->icsk_accept_queue); return -EADDRINUSE; } EXPORT_SYMBOL_GPL(inet_csk_listen_start); @@ -780,8 +776,6 @@ void inet_csk_listen_stop(struct sock *sk) * To be honest, we are not able to make either * of the variants now. --ANK */ - reqsk_queue_destroy(queue); - while ((req = reqsk_queue_remove(queue, sk)) != NULL) { struct sock *child = req->sk;