On Mon, Oct 29, 2018 at 2:54 PM John Hurley [off-list ref] wrote:

On Sun, Oct 28, 2018 at 11:10 AM Or Gerlitz [off-list ref] wrote:

quoted

On Thu, Oct 25, 2018 at 3:28 PM John Hurley [off-list ref] wrote:

quoted

Currently drivers can register to receive TC block bind/unbind callbacks
by implementing the setup_tc ndo in any of their given netdevs. However,
drivers may also be interested in binds to higher level devices (e.g.
tunnel drivers) to potentially offload filters applied to them.

quoted

Introduce indirect block devs which allows drivers to register callbacks
for block binds on other devices. The calling driver is expected to
reference an 'owner' struct that it will pass to all block registrations.
This is used to track the callbacks from a given driver and free them if
the driver is removed while the upper level device is still active.

quoted

Maybe it would be better to follow the trusted environment model of the kernel
and not protect the core from driver bugs? If the driver does things right they
will unregister before bailing out and if not, they will have to fix..

The owner stuff just makes it easier for a driver to track the blocks
it has registered for and, in turn, release these when exiting.
We could just leave this up to the driver to ensure it properly cleans
up after itself.

If it makes the life of the driver easier and doesn't add notable complexity,
then I think I am good to leave it

I don't feel that strongly either way.

m2

So lets see if other comment here, if not, we can just leave it, I guess

quoted

quoted

Allow registering an indirect block dev callback for a device that is
already bound to a block. In this case (if it is an ingress block),
register and also trigger the callback meaning that any already installed
rules can be replayed to the calling driver.

quoted

not just can be replayed.. they will be replayed, but through an
existing (tc re-offload?) facility, correct?

Yes, currently in TC, when you register for rule callbacks to a block
that already has rules, these rules are replayed.
With the indirect block approach we still use the same mechanism for
requesting rule callbacks,

sounds good