[ovs-dev] [PATCH] ofproto-dpif: Init ukey->dump_seq to zero

[Ben Pfaff]

On Wed, Apr 04, 2018 at 01:26:02PM +0200, Jan Scheurich wrote:
> In the current implementation the dump_seq of a new datapath flow ukey
> is set to seq_read(udpif->dump_seq). This implies that any revalidation
> during the current dump_seq period (up to 500 ms) is skipped.
> 
> This can trigger incorrect behavior, for example when the the creation of
> datapath flow triggers a PACKET_IN to the controller, which which course
> the controller installs a new flow entry that should invalidate the
> original datapath flow.
> 
> Initializing ukey->dump_seq to zero implies that the first dump of the
> flow, be it for revalidation or dumping statistics, will always be
> executed as zero is not a valid value of the ovs_seq.
> 
> Signed-off-by: Jan Scheurich <jan.scheurich at ericsson.com>

If we are going to do this, then we should delete the 'dump_seq' member
of struct upcall, because it will always be zero.  It is also worth
considering whether the other caller of ukey_create__() should pass 0,
and if so then we can delete the 'dump_seq' parameter of
ukey_create__().

Thanks,

Ben.