On Fri, 2005-01-21 at 15:23 -0800, David S. Miller wrote:
> On Thu, 30 Dec 2004 03:48:35 -0500
> David Dillow <dave@xxxxxxxxxxxxxx> wrote:
> > # This is a BitKeeper generated diff -Nru style patch.
> > #
> > # ChangeSet
> > # 2004/12/30 00:37:44-05:00 dave@xxxxxxxxxxxxxx
> > # Give device drivers a method to allow the use of crypto
> > # offload features for existing xfrm_states and bundles, as
> > # well as dynamically remove crypto offload capabilities.
> > #
> > # Signed-off-by: David Dillow <dave@xxxxxxxxxxxxxx>
> This change looks fine, but it reminds me of something.
> We have to make sure there is no way for xfrm_offloads to
> refer to a device when it is brought down.
> One way to ensure that, is to make each xfrm_offload attached
> grab a reference to the device it is for. The refcounting will
> help catch cases where stale xfrm_offload are around at
> unregister_netdev() time.
You're right, it would be a problem, and I have the oopsen to prove
In patch 3 of the series, xfrm_offload_add() grabs a reference to the
device, and xfrm_offload_release() releases it when the offload's own
reference count hits zero.
David Dillow <dave@xxxxxxxxxxxxxx>