svcrdma: Select NFSv4.1 backchannel transport based on forward channel
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@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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 @@
}
}
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: