From 849f67c7e1843fbad81a6e0dbbbb1614acbe9c11 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 16 Jul 2014 15:38:32 -0400 Subject: svcrdma: Select NFSv4.1 backchannel transport based on forward channel commit 3c45ddf823d679a820adddd53b52c6699c9a05ac upstream. 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 Signed-off-by: J. Bruce Fields Signed-off-by: Jiri Slaby --- fs/nfsd/nfs4callback.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index 3eaa6e30a2dc..cc8c5b32043c 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -672,7 +672,8 @@ 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 */ -- cgit v1.2.3