Commit aac065c5 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

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: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fff1f300

include/net/request_sock.h

+10 −30
Original line number Diff line number Diff line
@@ -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)

net/core/request_sock.c

+4 −4
Original line number Diff line number Diff line
@@ -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);

}

net/ipv4/inet_connection_sock.c

+3 −3
Original line number Diff line number Diff line
@@ -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;

net/ipv4/inet_diag.c

+1 −1
Original line number Diff line number Diff line
@@ -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) {

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