[RFC PATCH v1 03/10] net: qrtr: support identical node ids

From: Denis Kenzior
Date: Fri Oct 18 2024 - 14:21:14 EST


Add support for tracking multiple endpoints that may have conflicting
node identifiers. This is achieved by using both the node and endpoint
identifiers as the key inside the radix_tree data structure.

For backward compatibility with existing clients, the previous key
schema (node identifier only) is preserved. However, this schema will
only support the first endpoint/node combination. This is acceptable
for legacy clients as support for multiple endpoints with conflicting
node identifiers was not previously possible.

Signed-off-by: Denis Kenzior <denkenz@xxxxxxxxx>
Reviewed-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Reviewed-by: Andy Gross <agross@xxxxxxxxxx>
---
net/qrtr/af_qrtr.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/net/qrtr/af_qrtr.c b/net/qrtr/af_qrtr.c
index be275871fb2a..e83d491a8da9 100644
--- a/net/qrtr/af_qrtr.c
+++ b/net/qrtr/af_qrtr.c
@@ -418,12 +418,20 @@ static struct qrtr_node *qrtr_node_lookup(unsigned int nid)
static void qrtr_node_assign(struct qrtr_node *node, unsigned int nid)
{
unsigned long flags;
+ unsigned long key;

if (nid == QRTR_EP_NID_AUTO)
return;

spin_lock_irqsave(&qrtr_nodes_lock, flags);
- radix_tree_insert(&qrtr_nodes, nid, node);
+
+ /* Always insert with the endpoint_id + node_id */
+ key = (unsigned long)node->ep->id << 32 | nid;
+ radix_tree_insert(&qrtr_nodes, key, node);
+
+ if (!radix_tree_lookup(&qrtr_nodes, nid))
+ radix_tree_insert(&qrtr_nodes, nid, node);
+
if (node->nid == QRTR_EP_NID_AUTO)
node->nid = nid;
spin_unlock_irqrestore(&qrtr_nodes_lock, flags);
--
2.45.2