net: bridge: mcast: add delete due to fast-leave mdb flag

In user-space there's no way to distinguish why an mdb entry was deleted
and that is a problem for daemons which would like to keep the mdb in
sync with remote ends (e.g. mlag) but would also like to converge faster.
In almost all cases we'd like to age-out the remote entry for performance
and convergence reasons except when fast-leave is enabled. In that case we
want explicit immediate remote delete, thus add mdb flag which is set only
when the entry is being deleted due to fast-leave.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_private.h

@@ -199,6 +199,7 @@ struct net_bridge_fdb_entry {
 
 #define MDB_PG_FLAGS_PERMANENT	BIT(0)
 #define MDB_PG_FLAGS_OFFLOAD	BIT(1)
+#define MDB_PG_FLAGS_FAST_LEAVE	BIT(2)
 
 struct net_bridge_port_group {
 	struct net_bridge_port		*port;