Merge Linus master into drm-next

The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.

I've included the patch into the merge to fix the build.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 86 insertions, 54 deletions

diff --git a/include/net/request_sock.h b/include/net/request_sock.h
index 7f830ff67f08..fe41f3ceb008 100644
--- a/include/net/request_sock.h
+++ b/include/net/request_sock.h
@@ -39,8 +39,7 @@ struct request_sock_ops {
 	void		(*send_reset)(struct sock *sk,
 				      struct sk_buff *skb);
 	void		(*destructor)(struct request_sock *req);
-	void		(*syn_ack_timeout)(struct sock *sk,
-					   struct request_sock *req);
+	void		(*syn_ack_timeout)(const struct request_sock *req);
 };
 
 int inet_rtx_syn_ack(struct sock *parent, struct request_sock *req);
@@ -49,7 +48,11 @@ int inet_rtx_syn_ack(struct sock *parent, struct request_sock *req);
  */
 struct request_sock {
 	struct sock_common		__req_common;
+#define rsk_refcnt			__req_common.skc_refcnt
+#define rsk_hash			__req_common.skc_hash
+
 	struct request_sock		*dl_next;
+	struct sock			*rsk_listener;
 	u16				mss;
 	u8				num_retrans; /* number of retransmits */
 	u8				cookie_ts:1; /* syncookie: encode tcpopts in timestamp */
@@ -58,32 +61,56 @@ struct request_sock {
 	u32				window_clamp; /* window clamp at creation time */
 	u32				rcv_wnd;	  /* rcv_wnd offered first time */
 	u32				ts_recent;
-	unsigned long			expires;
+	struct timer_list		rsk_timer;
 	const struct request_sock_ops	*rsk_ops;
 	struct sock			*sk;
 	u32				secid;
 	u32				peer_secid;
 };
 
-static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops)
+static inline struct request_sock *
+reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk_listener)
 {
 	struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC);
 
-	if (req != NULL)
+	if (req) {
 		req->rsk_ops = ops;
-
+		sock_hold(sk_listener);
+		req->rsk_listener = sk_listener;
+
+		/* Following is temporary. It is coupled with debugging
+		 * helpers in reqsk_put() & reqsk_free()
+		 */
+		atomic_set(&req->rsk_refcnt, 0);
+	}
 	return req;
 }
 
-static inline void __reqsk_free(struct request_sock *req)
+static inline struct request_sock *inet_reqsk(struct sock *sk)
 {
-	kmem_cache_free(req->rsk_ops->slab, req);
+	return (struct request_sock *)sk;
+}
+
+static inline struct sock *req_to_sk(struct request_sock *req)
+{
+	return (struct sock *)req;
 }
 
 static inline void reqsk_free(struct request_sock *req)
 {
+	/* temporary debugging */
+	WARN_ON_ONCE(atomic_read(&req->rsk_refcnt) != 0);
+
 	req->rsk_ops->destructor(req);
-	__reqsk_free(req);
+	if (req->rsk_listener)
+		sock_put(req->rsk_listener);
+	kmem_cache_free(req->rsk_ops->slab, req);
+}
+
+static inline void reqsk_put(struct request_sock *req)
+{
+	if (atomic_dec_and_test(&req->rsk_refcnt))
+		reqsk_free(req);
 }
 
 extern int sysctl_max_syn_backlog;
@@ -93,12 +120,16 @@ extern int sysctl_max_syn_backlog;
  * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs
  */
 struct listen_sock {
-	u8			max_qlen_log;
+	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;
+
+	u8			max_qlen_log ____cacheline_aligned_in_smp;
 	u8			synflood_warned;
 	/* 2 bytes hole, try to use */
-	int			qlen;
-	int			qlen_young;
-	int			clock_hand;
 	u32			hash_rnd;
 	u32			nr_table_entries;
 	struct request_sock	*syn_table[0];
@@ -142,18 +173,11 @@ struct fastopen_queue {
  * %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).
  *
- * This lock is acquired in read mode only from listening_get_next() seq_file
- * op and it's acquired in write mode _only_ from code that is actively
- * changing rskq_accept_head. All readers that are holding the master sock lock
- * don't need to grab this lock in read mode too as rskq_accept_head. writes
- * are always protected from the main sock lock.
  */
 struct request_sock_queue {
 	struct request_sock	*rskq_accept_head;
 	struct request_sock	*rskq_accept_tail;
-	rwlock_t		syn_wait_lock;
 	u8			rskq_defer_accept;
-	/* 3 bytes hole, try to pack */
 	struct listen_sock	*listen_opt;
 	struct fastopen_queue	*fastopenq; /* This is non-NULL iff TFO has been
 					     * enabled on this listener. Check
@@ -161,6 +185,9 @@ struct request_sock_queue {
 					     * to determine if TFO is enabled
 					     * right at this moment.
 					     */
+
+	/* 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,
@@ -186,12 +213,21 @@ static inline int reqsk_queue_empty(struct request_sock_queue *queue)
 }
 
 static inline void reqsk_queue_unlink(struct request_sock_queue *queue,
-				      struct request_sock *req,
-				      struct request_sock **prev_req)
+				      struct request_sock *req)
 {
-	write_lock(&queue->syn_wait_lock);
-	*prev_req = req->dl_next;
-	write_unlock(&queue->syn_wait_lock);
+	struct listen_sock *lopt = queue->listen_opt;
+	struct request_sock **prev;
+
+	spin_lock(&queue->syn_wait_lock);
+
+	prev = &lopt->syn_table[req->rsk_hash];
+	while (*prev != req)
+		prev = &(*prev)->dl_next;
+	*prev = req->dl_next;
+
+	spin_unlock(&queue->syn_wait_lock);
+	if (del_timer(&req->rsk_timer))
+		reqsk_put(req);
 }
 
 static inline void reqsk_queue_add(struct request_sock_queue *queue,
@@ -224,57 +260,53 @@ static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue
 	return req;
 }
 
-static inline int reqsk_queue_removed(struct request_sock_queue *queue,
-				      struct request_sock *req)
+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)
-		--lopt->qlen_young;
-
-	return --lopt->qlen;
+		atomic_inc(&lopt->young_dec);
+	atomic_inc(&lopt->qlen_dec);
 }
 
-static inline int reqsk_queue_added(struct request_sock_queue *queue)
+static inline void reqsk_queue_added(struct request_sock_queue *queue)
 {
 	struct listen_sock *lopt = queue->listen_opt;
-	const int prev_qlen = lopt->qlen;
 
-	lopt->qlen_young++;
-	lopt->qlen++;
-	return prev_qlen;
+	lopt->young_inc++;
+	lopt->qlen_inc++;
 }
 
-static inline int reqsk_queue_len(const struct request_sock_queue *queue)
+static inline int listen_sock_qlen(const struct listen_sock *lopt)
 {
-	return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0;
+	return lopt->qlen_inc - atomic_read(&lopt->qlen_dec);
 }
 
-static inline int reqsk_queue_len_young(const struct request_sock_queue *queue)
+static inline int listen_sock_young(const struct listen_sock *lopt)
 {
-	return queue->listen_opt->qlen_young;
+	return lopt->young_inc - atomic_read(&lopt->young_dec);
 }
 
-static inline int reqsk_queue_is_full(const struct request_sock_queue *queue)
+static inline int reqsk_queue_len(const struct request_sock_queue *queue)
 {
-	return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log;
+	const struct listen_sock *lopt = queue->listen_opt;
+
+	return lopt ? listen_sock_qlen(lopt) : 0;
 }
 
-static inline void reqsk_queue_hash_req(struct request_sock_queue *queue,
-					u32 hash, struct request_sock *req,
-					unsigned long timeout)
+static inline int reqsk_queue_len_young(const struct request_sock_queue *queue)
 {
-	struct listen_sock *lopt = queue->listen_opt;
-
-	req->expires = jiffies + timeout;
-	req->num_retrans = 0;
-	req->num_timeout = 0;
-	req->sk = NULL;
-	req->dl_next = lopt->syn_table[hash];
+	return listen_sock_young(queue->listen_opt);
+}
 
-	write_lock(&queue->syn_wait_lock);
-	lopt->syn_table[hash] = req;
-	write_unlock(&queue->syn_wait_lock);
+static inline int reqsk_queue_is_full(const struct request_sock_queue *queue)
+{
+	return reqsk_queue_len(queue) >> queue->listen_opt->max_qlen_log;
 }
 
+void reqsk_queue_hash_req(struct request_sock_queue *queue,
+			  u32 hash, struct request_sock *req,
+			  unsigned long timeout);
+
 #endif /* _REQUEST_SOCK_H */