batman-adv: tp_meter: keep unacked list for receivers

There is no need to share the unacked list between sender and receivers.
Only receivers will ever write to and read from it. The initialization in
batadv_tp_start() was therefore never needed. After its removal, it is
enough to just store it in struct batadv_tp_receiver.

Signed-off-by: Sven Eckelmann <sven@narfation.org>

2 files changed, 71 insertions, 59 deletions

diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c
index 5cc719c81ea0..f18ce360839d 100644
--- a/net/batman-adv/tp_meter.c
+++ b/net/batman-adv/tp_meter.c
@@ -358,28 +358,16 @@ batadv_tp_list_find_sender_session(struct batadv_priv *bat_priv, const u8 *dst,
 }
 
 /**
- * batadv_tp_vars_common_release() - release batadv_tp_vars_common from lists
+ * batadv_tp_sender_release() - release batadv_tp_sender
  *  and queue for free after rcu grace period
- * @ref: kref pointer of the batadv_tp_vars_common
+ * @ref: kref pointer of the batadv_tp_sender
  */
-static void batadv_tp_vars_common_release(struct kref *ref)
+static void batadv_tp_sender_release(struct kref *ref)
 {
-	struct batadv_tp_vars_common *tp_vars;
-	struct batadv_tp_unacked *un, *safe;
-
-	tp_vars = container_of(ref, struct batadv_tp_vars_common, refcount);
-
-	/* lock should not be needed because this object is now out of any
-	 * context!
-	 */
-	spin_lock_bh(&tp_vars->unacked_lock);
-	list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) {
-		list_del(&un->list);
-		kfree(un);
-	}
-	spin_unlock_bh(&tp_vars->unacked_lock);
+	struct batadv_tp_sender *tp_vars;
 
-	kfree_rcu(tp_vars, rcu);
+	tp_vars = container_of(ref, struct batadv_tp_sender, common.refcount);
+	kfree_rcu(tp_vars, common.rcu);
 }
 
 /**
@@ -392,7 +380,7 @@ static void batadv_tp_sender_put(struct batadv_tp_sender *tp_vars)
 	if (!tp_vars)
 		return;
 
-	kref_put(&tp_vars->common.refcount, batadv_tp_vars_common_release);
+	kref_put(&tp_vars->common.refcount, batadv_tp_sender_release);
 }
 
 /**
@@ -1145,9 +1133,6 @@ void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst,
 	init_waitqueue_head(&tp_vars->more_bytes);
 	init_completion(&tp_vars->finished);
 
-	spin_lock_init(&tp_vars->common.unacked_lock);
-	INIT_LIST_HEAD(&tp_vars->common.unacked_list);
-
 	spin_lock_init(&tp_vars->cc_lock);
 
 	tp_vars->prerandom_offset = 0;
@@ -1252,6 +1237,33 @@ batadv_tp_list_find_receiver_session(struct batadv_priv *bat_priv, const u8 *dst
 }
 
 /**
+ * batadv_tp_receiver_release() - release batadv_tp_receiver
+ *  and queue for free after rcu grace period
+ * @ref: kref pointer of the batadv_tp_receiver
+ */
+static void batadv_tp_receiver_release(struct kref *ref)
+{
+	struct batadv_tp_receiver *tp_vars;
+	struct batadv_tp_unacked *safe;
+	struct batadv_tp_unacked *un;
+
+	tp_vars = container_of(ref, struct batadv_tp_receiver, common.refcount);
+
+	/* lock should not be needed because this object is now out of any
+	 * context!
+	 */
+	spin_lock_bh(&tp_vars->unacked_lock);
+	list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) {
+		list_del(&un->list);
+		kfree(un);
+		tp_vars->unacked_count--;
+	}
+	spin_unlock_bh(&tp_vars->unacked_lock);
+
+	kfree_rcu(tp_vars, common.rcu);
+}
+
+/**
  * batadv_tp_receiver_put() - decrement the batadv_tp_receiver
  *  refcounter and possibly release it
  * @tp_vars: the private data of the current TP meter session to be free'd
@@ -1261,7 +1273,7 @@ static void batadv_tp_receiver_put(struct batadv_tp_receiver *tp_vars)
 	if (!tp_vars)
 		return;
 
-	kref_put(&tp_vars->common.refcount, batadv_tp_vars_common_release);
+	kref_put(&tp_vars->common.refcount, batadv_tp_receiver_release);
 }
 
 /**
@@ -1304,13 +1316,13 @@ static void batadv_tp_receiver_shutdown(struct timer_list *t)
 	if (batadv_tp_list_detach(&tp_vars->common))
 		batadv_tp_receiver_put(tp_vars);
 
-	spin_lock_bh(&tp_vars->common.unacked_lock);
-	list_for_each_entry_safe(un, safe, &tp_vars->common.unacked_list, list) {
+	spin_lock_bh(&tp_vars->unacked_lock);
+	list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) {
 		list_del(&un->list);
 		kfree(un);
-		tp_vars->common.unacked_count--;
+		tp_vars->unacked_count--;
 	}
-	spin_unlock_bh(&tp_vars->common.unacked_lock);
+	spin_unlock_bh(&tp_vars->unacked_lock);
 
 	/* drop reference of timer */
 	if (WARN_ON(atomic_xchg(&tp_vars->receiving, 0) != 1))
@@ -1403,7 +1415,7 @@ out:
  */
 static bool batadv_tp_handle_out_of_order(struct batadv_tp_receiver *tp_vars,
 					  u32 seqno, u32 payload_len)
-	__must_hold(&tp_vars->common.unacked_lock)
+	__must_hold(&tp_vars->unacked_lock)
 {
 	struct batadv_tp_unacked *un, *new;
 	struct batadv_tp_unacked *safe;
@@ -1417,9 +1429,9 @@ static bool batadv_tp_handle_out_of_order(struct batadv_tp_receiver *tp_vars,
 	new->len = payload_len;
 
 	/* if the list is empty immediately attach this new object */
-	if (list_empty(&tp_vars->common.unacked_list)) {
-		list_add(&new->list, &tp_vars->common.unacked_list);
-		tp_vars->common.unacked_count++;
+	if (list_empty(&tp_vars->unacked_list)) {
+		list_add(&new->list, &tp_vars->unacked_list);
+		tp_vars->unacked_count++;
 		return true;
 	}
 
@@ -1430,7 +1442,7 @@ static bool batadv_tp_handle_out_of_order(struct batadv_tp_receiver *tp_vars,
 	 * the last received packet (the one being processed now) has a bigger
 	 * seqno than all the others already stored.
 	 */
-	list_for_each_entry_reverse(un, &tp_vars->common.unacked_list, list) {
+	list_for_each_entry_reverse(un, &tp_vars->unacked_list, list) {
 		/* look for the right position - an un which is smaller */
 		if (batadv_seq_before(new->seqno, un->seqno))
 			continue;
@@ -1476,19 +1488,19 @@ static bool batadv_tp_handle_out_of_order(struct batadv_tp_receiver *tp_vars,
 		 */
 		list_add(&new->list, &un->list);
 		added = true;
-		tp_vars->common.unacked_count++;
+		tp_vars->unacked_count++;
 		break;
 	}
 
 	/* received packet with smallest seqno out of order; add it to front */
 	if (!added) {
-		list_add(&new->list, &tp_vars->common.unacked_list);
-		tp_vars->common.unacked_count++;
+		list_add(&new->list, &tp_vars->unacked_list);
+		tp_vars->unacked_count++;
 	}
 
 	/* check if new filled the gap to the next list entries */
 	un = new;
-	list_for_each_entry_safe_continue(un, safe, &tp_vars->common.unacked_list, list) {
+	list_for_each_entry_safe_continue(un, safe, &tp_vars->unacked_list, list) {
 		if (batadv_seq_before(new->seqno + new->len, un->seqno))
 			break;
 
@@ -1499,16 +1511,16 @@ static bool batadv_tp_handle_out_of_order(struct batadv_tp_receiver *tp_vars,
 
 		list_del(&un->list);
 		kfree(un);
-		tp_vars->common.unacked_count--;
+		tp_vars->unacked_count--;
 	}
 
 	/* remove the last (biggest) unacked seqno when list is too large */
-	if (tp_vars->common.unacked_count > BATADV_TP_MAX_UNACKED) {
-		un = list_last_entry(&tp_vars->common.unacked_list,
+	if (tp_vars->unacked_count > BATADV_TP_MAX_UNACKED) {
+		un = list_last_entry(&tp_vars->unacked_list,
 				     struct batadv_tp_unacked, list);
 		list_del(&un->list);
 		kfree(un);
-		tp_vars->common.unacked_count--;
+		tp_vars->unacked_count--;
 	}
 
 	return true;
@@ -1520,7 +1532,7 @@ static bool batadv_tp_handle_out_of_order(struct batadv_tp_receiver *tp_vars,
  * @tp_vars: the private data of the current TP meter session
  */
 static void batadv_tp_ack_unordered(struct batadv_tp_receiver *tp_vars)
-	__must_hold(&tp_vars->common.unacked_lock)
+	__must_hold(&tp_vars->unacked_lock)
 {
 	struct batadv_tp_unacked *un, *safe;
 	u32 to_ack;
@@ -1528,7 +1540,7 @@ static void batadv_tp_ack_unordered(struct batadv_tp_receiver *tp_vars)
 	/* go through the unacked packet list and possibly ACK them as
 	 * well
 	 */
-	list_for_each_entry_safe(un, safe, &tp_vars->common.unacked_list, list) {
+	list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) {
 		/* the list is ordered, therefore it is possible to stop as soon
 		 * there is a gap between the last acked seqno and the seqno of
 		 * the packet under inspection
@@ -1543,7 +1555,7 @@ static void batadv_tp_ack_unordered(struct batadv_tp_receiver *tp_vars)
 
 		list_del(&un->list);
 		kfree(un);
-		tp_vars->common.unacked_count--;
+		tp_vars->unacked_count--;
 	}
 }
 
@@ -1590,9 +1602,9 @@ batadv_tp_init_recv(struct batadv_priv *bat_priv,
 	tp_vars->common.bat_priv = bat_priv;
 	kref_init(&tp_vars->common.refcount);
 
-	spin_lock_init(&tp_vars->common.unacked_lock);
-	INIT_LIST_HEAD(&tp_vars->common.unacked_list);
-	tp_vars->common.unacked_count = 0;
+	spin_lock_init(&tp_vars->unacked_lock);
+	INIT_LIST_HEAD(&tp_vars->unacked_list);
+	tp_vars->unacked_count = 0;
 
 	kref_get(&tp_vars->common.refcount);
 	timer_setup(&tp_vars->common.timer, batadv_tp_receiver_shutdown, 0);
@@ -1652,7 +1664,7 @@ static void batadv_tp_recv_msg(struct batadv_priv *bat_priv,
 		WRITE_ONCE(tp_vars->last_recv_time, jiffies);
 	}
 
-	spin_lock_bh(&tp_vars->common.unacked_lock);
+	spin_lock_bh(&tp_vars->unacked_lock);
 
 	/* if the packet is a duplicate, it may be the case that an ACK has been
 	 * lost. Resend the ACK
@@ -1668,7 +1680,7 @@ static void batadv_tp_recv_msg(struct batadv_priv *bat_priv,
 		 * not been enqueued correctly
 		 */
 		if (!batadv_tp_handle_out_of_order(tp_vars, seqno, payload_len)) {
-			spin_unlock_bh(&tp_vars->common.unacked_lock);
+			spin_unlock_bh(&tp_vars->unacked_lock);
 			goto out;
 		}
 
@@ -1684,7 +1696,7 @@ static void batadv_tp_recv_msg(struct batadv_priv *bat_priv,
 
 send_ack:
 	to_ack = tp_vars->last_recv;
-	spin_unlock_bh(&tp_vars->common.unacked_lock);
+	spin_unlock_bh(&tp_vars->unacked_lock);
 
 	/* send the ACK. If the received packet was out of order, the ACK that
 	 * is going to be sent is a duplicate (the sender will count them and
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index c2ab00d8ef16..c194d8069774 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -1334,7 +1334,7 @@ struct batadv_tp_unacked {
 	/** @len: length of the packet */
 	u32 len;
 
-	/** @list: list node for &batadv_tp_vars_common.unacked_list */
+	/** @list: list node for &batadv_tp_receiver.unacked_list */
 	struct list_head list;
 };
 
@@ -1357,15 +1357,6 @@ struct batadv_tp_vars_common {
 	/** @session: TP session identifier */
 	u8 session[2];
 
-	/** @unacked_list: list of unacked packets (meta-info only) */
-	struct list_head unacked_list;
-
-	/** @unacked_lock: protect unacked_list + &batadv_tp_receiver.last_recv */
-	spinlock_t unacked_lock;
-
-	/** @unacked_count: number of unacked entries */
-	size_t unacked_count;
-
 	/** @refcount: number of context where the object is used */
 	struct kref refcount;
 
@@ -1479,6 +1470,15 @@ struct batadv_tp_receiver {
 
 	/** @last_recv_time: time (jiffies) a msg was received */
 	unsigned long last_recv_time;
+
+	/** @unacked_list: list of unacked packets (meta-info only) */
+	struct list_head unacked_list;
+
+	/** @unacked_lock: protect unacked_list + &batadv_tp_receiver.last_recv */
+	spinlock_t unacked_lock;
+
+	/** @unacked_count: number of unacked entries */
+	size_t unacked_count;
 };
 
 /**