From bb300aedea872033326b0d52703c4df69b299de2 Mon Sep 17 00:00:00 2001
From: Chris Lew <clew@codeaurora.org>
Date: Tue, 17 Jul 2018 14:08:33 -0700
Subject: [PATCH] net: qrtr: Send BYE message for all nodes on ept

An ept can represent multiple nodes in a system. If an ept unregisters,
qrtr should send a BYE control message for all the nodes that it
represents. Iterate through the node tree to find all the nodes that
belong to the ept.

Change-Id: I641bba615e689f59acecc9ac87fec61c3eecc0d1
Signed-off-by: Chris Lew <clew@codeaurora.org>
---
 net/qrtr/qrtr.c | 37 +++++++++++++++++++++++++++++--------
 1 file changed, 29 insertions(+), 8 deletions(-)

diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
index 70e722932538..b93c9ea38480 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -638,28 +638,49 @@ int qrtr_endpoint_register(struct qrtr_endpoint *ep, unsigned int nid)
 }
 EXPORT_SYMBOL_GPL(qrtr_endpoint_register);
 
+static void qrtr_notify_bye(u32 nid)
+{
+	struct sockaddr_qrtr src = {AF_QIPCRTR, nid, QRTR_PORT_CTRL};
+	struct sockaddr_qrtr dst = {AF_QIPCRTR, qrtr_local_nid, QRTR_PORT_CTRL};
+	struct qrtr_ctrl_pkt *pkt;
+	struct sk_buff *skb;
+
+	skb = qrtr_alloc_ctrl_packet(&pkt);
+	if (!skb)
+		return;
+
+	pkt->cmd = cpu_to_le32(QRTR_TYPE_BYE);
+	qrtr_local_enqueue(NULL, skb, QRTR_TYPE_BYE, &src, &dst);
+}
+
 /**
  * qrtr_endpoint_unregister - unregister endpoint
  * @ep: endpoint to unregister
  */
 void qrtr_endpoint_unregister(struct qrtr_endpoint *ep)
 {
+	struct radix_tree_iter iter;
 	struct qrtr_node *node = ep->node;
-	struct sockaddr_qrtr src = {AF_QIPCRTR, node->nid, QRTR_PORT_CTRL};
-	struct sockaddr_qrtr dst = {AF_QIPCRTR, qrtr_local_nid, QRTR_PORT_CTRL};
-	struct qrtr_ctrl_pkt *pkt;
-	struct sk_buff *skb;
+	unsigned long flags;
+	void __rcu **slot;
 
 	mutex_lock(&node->ep_lock);
 	node->ep = NULL;
 	mutex_unlock(&node->ep_lock);
 
 	/* Notify the local controller about the event */
-	skb = qrtr_alloc_ctrl_packet(&pkt);
-	if (skb) {
-		pkt->cmd = cpu_to_le32(QRTR_TYPE_BYE);
-		qrtr_local_enqueue(NULL, skb, QRTR_TYPE_BYE, &src, &dst);
+	down_read(&qrtr_epts_lock);
+	spin_lock_irqsave(&qrtr_nodes_lock, flags);
+	radix_tree_for_each_slot(slot, &qrtr_nodes, &iter, 0) {
+		if (node != *slot)
+			continue;
+
+		spin_unlock_irqrestore(&qrtr_nodes_lock, flags);
+		qrtr_notify_bye(iter.index);
+		spin_lock_irqsave(&qrtr_nodes_lock, flags);
 	}
+	spin_unlock_irqrestore(&qrtr_nodes_lock, flags);
+	up_read(&qrtr_epts_lock);
 
 	/* Wake up any transmitters waiting for resume-tx from the node */
 	wake_up_interruptible_all(&node->resume_tx);