On Wed, Jun 17, 2020 at 08:17:39AM +0300, Leon Romanovsky wrote: > > My thoughts that everything here hints me that state machine and > locking are implemented wrongly. In ideal world, the expectation > is that REQ message will have a state in it (PREPARED, SENT, ACK > e.t.c.) and list manipulations are done accordingly with proper > locks, while rdma_nl_multicast() is done outside of the locks. It can't be done outside the lock without creating races - once rdma_nl_multicast happens it is possible for the other leg of the operation to begin processing. The list must be updated before this happens. What is missing here is refcounting - the lifetime model of this data is too implicit, but it is not worth adding I think Jason