From 43f55f23f70881e9c397557f15c8090b368d0af2 Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Wed, 29 Sep 2021 15:26:08 +0800 Subject: mctp: Add refcounts to mctp_dev Currently, we tie the struct mctp_dev lifetime to the underlying struct net_device, and hold/put that device as a proxy for a separate mctp_dev refcount. This works because we're not holding any references to the mctp_dev that are different from the netdev lifetime. In a future change we'll break that assumption though, as we'll need to hold mctp_dev references in a workqueue, which might live past the netdev unregister notification. In order to support that, this change introduces a refcount on the mctp_dev, currently taken by the net_device->mctp_ptr reference, and released on netdev unregister events. We can then use this for future references that might outlast the net device. Signed-off-by: Jeremy Kerr Signed-off-by: David S. Miller --- include/net/mctpdevice.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/net/mctpdevice.h') diff --git a/include/net/mctpdevice.h b/include/net/mctpdevice.h index 71a11012fac7..3a439463f055 100644 --- a/include/net/mctpdevice.h +++ b/include/net/mctpdevice.h @@ -17,6 +17,8 @@ struct mctp_dev { struct net_device *dev; + refcount_t refs; + unsigned int net; /* Only modified under RTNL. Reads have addrs_lock held */ @@ -32,4 +34,7 @@ struct mctp_dev { struct mctp_dev *mctp_dev_get_rtnl(const struct net_device *dev); struct mctp_dev *__mctp_dev_get(const struct net_device *dev); +void mctp_dev_hold(struct mctp_dev *mdev); +void mctp_dev_put(struct mctp_dev *mdev); + #endif /* __NET_MCTPDEVICE_H */ -- cgit