From aac065c50aba0c534a929aeb687eb68c58e523b8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 2 Oct 2015 11:43:24 -0700 Subject: [PATCH] tcp: move qlen/young out of struct listen_sock qlen_inc & young_inc were protected by listener lock, while qlen_dec & young_dec were atomic fields. Everything needs to be atomic for upcoming lockless listener. Also move qlen/young in request_sock_queue as we'll get rid of struct listen_sock eventually. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/request_sock.h | 40 +++++++++------------------------ net/core/request_sock.c | 8 +++---- net/ipv4/inet_connection_sock.c | 6 ++--- net/ipv4/inet_diag.c | 2 +- 4 files changed, 18 insertions(+), 38 deletions(-) diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 202e36163ae3..d128e7f89042 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -122,14 +122,7 @@ extern int sysctl_max_syn_backlog; * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs */ struct listen_sock { - int qlen_inc; /* protected by listener lock */ - int young_inc;/* protected by listener lock */ - - /* following fields can be updated by timer */ - atomic_t qlen_dec; /* qlen = qlen_inc - qlen_dec */ - atomic_t young_dec; - - u32 max_qlen_log ____cacheline_aligned_in_smp; + u32 max_qlen_log; u32 synflood_warned; u32 hash_rnd; u32 nr_table_entries; @@ -179,6 +172,9 @@ struct request_sock_queue { spinlock_t rskq_lock; u8 rskq_defer_accept; + atomic_t qlen; + atomic_t young; + struct request_sock *rskq_accept_head; struct request_sock *rskq_accept_tail; struct listen_sock *listen_opt; @@ -242,41 +238,25 @@ static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue static inline void reqsk_queue_removed(struct request_sock_queue *queue, const struct request_sock *req) { - struct listen_sock *lopt = queue->listen_opt; - if (req->num_timeout == 0) - atomic_inc(&lopt->young_dec); - atomic_inc(&lopt->qlen_dec); + atomic_dec(&queue->young); + atomic_dec(&queue->qlen); } static inline void reqsk_queue_added(struct request_sock_queue *queue) { - struct listen_sock *lopt = queue->listen_opt; - - lopt->young_inc++; - lopt->qlen_inc++; -} - -static inline int listen_sock_qlen(const struct listen_sock *lopt) -{ - return lopt->qlen_inc - atomic_read(&lopt->qlen_dec); -} - -static inline int listen_sock_young(const struct listen_sock *lopt) -{ - return lopt->young_inc - atomic_read(&lopt->young_dec); + atomic_inc(&queue->young); + atomic_inc(&queue->qlen); } static inline int reqsk_queue_len(const struct request_sock_queue *queue) { - const struct listen_sock *lopt = queue->listen_opt; - - return lopt ? listen_sock_qlen(lopt) : 0; + return atomic_read(&queue->qlen); } static inline int reqsk_queue_len_young(const struct request_sock_queue *queue) { - return listen_sock_young(queue->listen_opt); + return atomic_read(&queue->young); } static inline int reqsk_queue_is_full(const struct request_sock_queue *queue) diff --git a/net/core/request_sock.c b/net/core/request_sock.c index 8d9fd31d3d06..5ca624cea04c 100644 --- a/net/core/request_sock.c +++ b/net/core/request_sock.c @@ -102,7 +102,7 @@ void reqsk_queue_destroy(struct request_sock_queue *queue) /* make all the listen_opt local to us */ struct listen_sock *lopt = reqsk_queue_yank_listen_sk(queue); - if (listen_sock_qlen(lopt) != 0) { + if (reqsk_queue_len(queue) != 0) { unsigned int i; for (i = 0; i < lopt->nr_table_entries; i++) { @@ -116,7 +116,7 @@ void reqsk_queue_destroy(struct request_sock_queue *queue) * or risk a dead lock. */ spin_unlock_bh(&queue->syn_wait_lock); - atomic_inc(&lopt->qlen_dec); + atomic_dec(&queue->qlen); if (del_timer_sync(&req->rsk_timer)) reqsk_put(req); reqsk_put(req); @@ -126,8 +126,8 @@ void reqsk_queue_destroy(struct request_sock_queue *queue) } } - if (WARN_ON(listen_sock_qlen(lopt) != 0)) - pr_err("qlen %u\n", listen_sock_qlen(lopt)); + if (WARN_ON(reqsk_queue_len(queue) != 0)) + pr_err("qlen %u\n", reqsk_queue_len(queue)); kvfree(lopt); } diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 0085612b9e49..093ef04e6ebf 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -640,9 +640,9 @@ static void reqsk_timer_handler(unsigned long data) * embrions; and abort old ones without pity, if old * ones are about to clog our table. */ - qlen = listen_sock_qlen(lopt); + qlen = reqsk_queue_len(queue); if (qlen >> (lopt->max_qlen_log - 1)) { - int young = listen_sock_young(lopt) << 1; + int young = reqsk_queue_len_young(queue) << 1; while (thresh > 2) { if (qlen < young) @@ -664,7 +664,7 @@ static void reqsk_timer_handler(unsigned long data) unsigned long timeo; if (req->num_timeout++ == 0) - atomic_inc(&lopt->young_dec); + atomic_dec(&queue->young); timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX); mod_timer_pinned(&req->rsk_timer, jiffies + timeo); return; diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index c3b1f3a0f4cf..0ac1d68dc8a6 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -753,7 +753,7 @@ static int inet_diag_dump_reqs(struct sk_buff *skb, struct sock *sk, spin_lock(&icsk->icsk_accept_queue.syn_wait_lock); lopt = icsk->icsk_accept_queue.listen_opt; - if (!lopt || !listen_sock_qlen(lopt)) + if (!lopt || !reqsk_queue_len(&icsk->icsk_accept_queue)) goto out; if (bc) {