secchan: Eliminate UNKNOWN_SUPER.
When a super-rule is destroyed, secchan must reassess each of its subrules.
Each subrule might now have no super-rule (which we suspect is the common
case) or it might have a new super-rule.
Until now, secchan has "optimized" this reassessment by initially assigning
each of the deleted super-rule's subrules a super-rule of UNKNOWN_SUPER,
which is not a valid rule at all. It did this in the hope that the
subrule would get deleted before we need to know what its super-rule is.
However, this has repeatedly led to bugs, since it's not always obvious
what code will need to find a rule's super-rule.
This commit fixes the problem by removing the "optimization" (in quotes
because there is no evidence that it was a useful optimization in
practice).
projects / openvswitch / commit