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? 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
