Hi Hans,
So this approach has a fundamental problem, f->dst is changed without any synchronization
you cannot rely on it and thus you cannot account for these entries properly. We must be very
careful if we try to add any new synchronization not to affect performance as well.
More below...

quoted

@@ -319,6 +326,9 @@ static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f,
 	if (test_bit(BR_FDB_STATIC, &f->flags))
 		fdb_del_hw_addr(br, f->key.addr.addr);
 
+	if (test_bit(BR_FDB_ENTRY_LOCKED, &f->flags) && !test_bit(BR_FDB_OFFLOADED, &f->flags))
+		atomic_dec(&f->dst->locked_entry_cnt);

Sorry but you cannot do this for multiple reasons:
 - f->dst can be NULL
 - f->dst changes without any synchronization
 - there is no synchronization between fdb's flags and its ->dst

Cheers,
 Nik

Hi Nik,

I could check if f->dst is NULL, but in general this should be able to
work on a per port basis, so do you have an idea of how to keep a per
port counter of added locked fdb entries?

Best,
Hans