Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:57456 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751348AbaGQShm (ORCPT ); Thu, 17 Jul 2014 14:37:42 -0400 Date: Thu, 17 Jul 2014 14:37:41 -0400 From: "J. Bruce Fields" To: Chuck Lever Cc: linux-nfs@vger.kernel.org Subject: Re: [PATCH] svcrdma: Select NFSv4.1 backchannel transport based on forward channel Message-ID: <20140717183741.GB30442@fieldses.org> References: <20140716193542.7847.95868.stgit@klimt.1015granger.net> <20140717183621.GA30442@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20140717183621.GA30442@fieldses.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, Jul 17, 2014 at 02:36:21PM -0400, J. Bruce Fields wrote: > 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 > > --- > > Hi Bruce- > > > > What do you think of this approach? > > OK by me. (Applying for 3.17 unless you tell me otherwise.) --b. > (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) > >