Re: [PATCH net 2/2] nfp: reject binding to shared blocks

Mon, Jun 25, 2018 at 10:50:14PM CEST, jakub.kicinski@netronome.com wrote:

On Mon, 25 Jun 2018 22:40:21 +0200, Jiri Pirko wrote:

quoted

Mon, Jun 25, 2018 at 10:22:46PM CEST, jakub.kicinski@netronome.com wrote:

quoted

From: John Hurley <redacted>

TC shared blocks allow multiple qdiscs to be grouped together and filters
shared between them. Currently the chains of filters attached to a block
are only flushed when the block is removed. If a qdisc is removed from a
block but the block still exists, flow del messages are not passed to the
callback registered for that qdisc. For the NFP, this presents the
possibility of rules still existing in hw when they should be removed.

Prevent binding to shared blocks until the kernel can send per qdisc del
messages when block unbinds occur.  

This is not nfp-specific problem. Should be handled differently. The
driver has information about offloaded filters. On unbind, it have
enough info to do the flush, doesn't it?

Certainly.  But this fix is simpler and sufficient.  We need to
backport it back to 4.16.  If we have to go through driver tables 
and flush filters we may as well merge the reoffload series to net.

Oh, I missed this is for net. Sorry.

Acked-by: Jiri Pirko <redacted>