Bluetooth: l2cap: introduce l2cap_conn ref-counting

If we want to use l2cap_conn outside of l2cap_core.c, we need refcounting
for these objects. Otherwise, we cannot synchronize l2cap locks with
outside locks and end up with deadlocks.

Hence, introduce ref-counting for l2cap_conn objects. This doesn't affect
l2cap internals at all, as they use a direct synchronization.
We also keep a reference to the parent hci_conn for locking purposes as
l2cap_conn depends on this. This doesn't affect the connection itself but
only the lifetime of the (dead) object.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 278830ef92cd..7b4cc5b98535 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -583,6 +583,7 @@ struct l2cap_conn {
 
         struct list_head        chan_l;
         struct mutex            chan_lock;
+        struct kref             ref;
 };
 
 #define L2CAP_INFO_CL_MTU_REQ_SENT      0x01
@@ -813,4 +814,7 @@ void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan,
                        u8 status);
 void __l2cap_physical_cfm(struct l2cap_chan *chan, int result);
 
+void l2cap_conn_get(struct l2cap_conn *conn);
+void l2cap_conn_put(struct l2cap_conn *conn);
+
 #endif /* __L2CAP_H */