Hi, This patchset breaks compatibility...
On 04/02/2019 16.04, Santosh Shilimkar wrote: > --- a/net/rds/ib_cm.c > +++ b/net/rds/ib_cm.c > @@ -868,7 +870,7 @@ int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id, > bool isv6) > > /* If the peer doesn't do protocol negotiation, we must > * default to RDSv3.0 */ > - rds_ib_set_protocol(conn, RDS_PROTOCOL_VERSION); > + rds_ib_set_protocol(conn, RDS_PROTOCOL_4_1); > ic->i_flowctl = rds_ib_sysctl_flow_control; /* advertise flow > control */ > > ret = rds_ib_setup_qp(conn); The comment calls out to fallback to RDSv3.0, but the code assumes that v4.1 is the new common standard. If there's a mechanism that ensures compatibility with older (pre-4.1) versions of RDS I am not seeing it. The inconsistency in comment vs. code doesn't help in that regard. And tests illustrated this incompatibility: 2 peers with this patchset can talk to eachother. Peers with a mix of post-this-patchset and pre-this-patchset can no longer talk to eachother. Thanks, Gerd
