leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

mctp: Add refcounts to mctp_dev

Browse Source 
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 <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jeremy Kerr
2021-09-29 15:26:08 +08:00
committed by David S. Miller
parent 73c618456d
commit 43f55f23f7
4 changed files with 25 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
net/mctp/route.c
View File

@@ -455,7 +455,7 @@ static int mctp_route_output(struct mctp_route *route, struct sk_buff *skb)
static void mctp_route_release(struct mctp_route *rt)
{
if (refcount_dec_and_test(&rt->refs)) {
dev_put(rt->dev->dev);
mctp_dev_put(rt->dev);
kfree_rcu(rt, rcu);
}
}
@@ -815,7 +815,7 @@ static int mctp_route_add(struct mctp_dev *mdev, mctp_eid_t daddr_start,
rt->max = daddr_start + daddr_extent;
rt->mtu = mtu;
rt->dev = mdev;
dev_hold(rt->dev->dev);
mctp_dev_hold(rt->dev);
rt->type = type;
rt->output = rtfn;