On Wed, Jul 16, 2014 at 03:38:32PM -0400, Chuck Lever wrote: > The current code always selects XPRT_TRANSPORT_BC_TCP for the back > channel, even when the forward channel was not TCP (eg, RDMA). When > a 4.1 mount is attempted with RDMA, the server panics in the TCP BC > code when trying to send CB_NULL. > > Instead, construct the transport protocol number from the forward > channel transport or'd with XPRT_TRANSPORT_BC. Transports that do > not support bi-directional RPC will not have registered a "BC" > transport, causing create_backchannel_client() to fail immediately. > > Fixes: https://bugzilla.linux-nfs.org/show_bug.cgi?id=265 > Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> > --- > Hi Bruce- > > What do you think of this approach? OK by me. (So clients use a separate tcp connection for the backchannel?) --b. > > > fs/nfsd/nfs4callback.c | 3 ++- > include/linux/sunrpc/svc_xprt.h | 1 + > net/sunrpc/svcsock.c | 2 ++ > net/sunrpc/xprt.c | 2 +- > net/sunrpc/xprtrdma/svc_rdma_transport.c | 1 + > 5 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c > index 2c73cae..0f23ad0 100644 > --- a/fs/nfsd/nfs4callback.c > +++ b/fs/nfsd/nfs4callback.c > @@ -689,7 +689,8 @@ static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *c > clp->cl_cb_session = ses; > args.bc_xprt = conn->cb_xprt; > args.prognumber = clp->cl_cb_session->se_cb_prog; > - args.protocol = XPRT_TRANSPORT_BC_TCP; > + args.protocol = conn->cb_xprt->xpt_class->xcl_ident | > + XPRT_TRANSPORT_BC; > args.authflavor = ses->se_cb_sec.flavor; > } > /* Create RPC client */ > diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h > index 7235040..5d9d6f8 100644 > --- a/include/linux/sunrpc/svc_xprt.h > +++ b/include/linux/sunrpc/svc_xprt.h > @@ -33,6 +33,7 @@ struct svc_xprt_class { > struct svc_xprt_ops *xcl_ops; > struct list_head xcl_list; > u32 xcl_max_payload; > + int xcl_ident; > }; > > /* > diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c > index b507cd3..b2437ee 100644 > --- a/net/sunrpc/svcsock.c > +++ b/net/sunrpc/svcsock.c > @@ -692,6 +692,7 @@ static struct svc_xprt_class svc_udp_class = { > .xcl_owner = THIS_MODULE, > .xcl_ops = &svc_udp_ops, > .xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP, > + .xcl_ident = XPRT_TRANSPORT_UDP, > }; > > static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv) > @@ -1292,6 +1293,7 @@ static struct svc_xprt_class svc_tcp_class = { > .xcl_owner = THIS_MODULE, > .xcl_ops = &svc_tcp_ops, > .xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP, > + .xcl_ident = XPRT_TRANSPORT_TCP, > }; > > void svc_init_xprt_sock(void) > diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c > index c3b2b33..51c6316 100644 > --- a/net/sunrpc/xprt.c > +++ b/net/sunrpc/xprt.c > @@ -1306,7 +1306,7 @@ struct rpc_xprt *xprt_create_transport(struct xprt_create *args) > } > } > spin_unlock(&xprt_list_lock); > - printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident); > + dprintk("RPC: transport (%d) not supported\n", args->ident); > return ERR_PTR(-EIO); > > found: > diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c > index e7323fb..06a5d92 100644 > --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c > +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c > @@ -92,6 +92,7 @@ struct svc_xprt_class svc_rdma_class = { > .xcl_owner = THIS_MODULE, > .xcl_ops = &svc_rdma_ops, > .xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP, > + .xcl_ident = XPRT_TRANSPORT_RDMA, > }; > > struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt) > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
